AMA: Bryan Litz & Nick Vitalbo of Applied Ballistics

Welcome to TFB’s first AMA (Ask Me Anything). Our debut AMA’ers are Bryan Litz, Ballistician, Author and President of Applied Ballistics and Nick Vitalbo, Principal Engineer at Applied Ballistics.

This is your chance to ask two of the top firearm ballistic experts in the country any questions you have about ballistics, gun accuracy, long range shooting and the future of firearms. Check out their website to get an idea of what these guys do.

Here is how the AMA works:

1. Ask any question in the comments below.

2. Bryan & Nick will monitor this webpage on Wednesday and answer questions as soon as they can by replying to them in the comments.

3. Be polite. Nick and Bryan are our guests are not required to answer every question asked.

Bryan Litz – Ballistician, President of Applied Ballistics, Inc.

Bryan graduated from Penn State University with a degree in Aerospace Engineering in 2002. Following graduation, he began a career working for the US Air Force on Air-to-Missile design, modeling and simulation; spending six years at Wright-Patterson Air-Force Base.  In November 2008, he left the government and became the Chief Ballistician for Berger Bullets.

Bryan founded Applied Ballistics and has written many ballistics programs and technical papers dealing with long-range flight dynamics of projectiles. His books, “Applied Ballistics for Long Range Shooting“ and “Accuracy and Precision for Long Range Shooting ” have been widely received in the shooting and precision marksmanship communities.  They are considered invaluable assets to the art of long-range shooting and ballistics.

Additionally, Bryan is a champion long-range shooter who has won numerous regional, national and international tournaments.

Nick Vitalbo – Principal Engineer at Applied Ballistics, President of nVisti Technology Inc.
Nick obtained both his B.S. in Electrical Engineering and B.A. in Computer Science from Bucknell University in 2003 with areas of concentration on Physics and Mathematics.

For the next eight years, he worked for Lockheed Martin where he was the Engineering Program Manager and Chief Engineer for Lockheed Martin’s Precision Engagement Technology Group.  During that time, Nick was responsible for the developing the system design of the One Shot wind measurement system and he is the principal investigator for several wind measurement and ballistics programs within the U.S. government.

Nick has partnered with Applied Ballistics and has been the technical lead on the IBEAM program executed through Applied Ballistics, Inc. and responsible for the development and integration of the hardware and software for the Applied Ballistics Kestrel devices, the Rapid Engagement Modules, the Wind Sensor Array systems, as well as the Applied Ballistics Tactical Application (US military only).

Additionally, he has developed several other ballistics and wind sensing applications such as the Applied Ballistics Wind Sensor Array and the Android version of the Applied Ballistics Tactical Solver.

His specialties include hardware / software Integration, laser beam propagation, and EO/IR sensors systems.

Modern Advancements for Long Range Shooting by Bryan Litz

Modern Advancements for Long Range Shooting is a book series by Bryan Litz, which documents the ongoing R&D taking place in the Applied Ballistics laboratory.  Volume I of the series is scheduled for release in late July 2014. 

In the first Volume, extensive test results are presented which fully explore the effects of twist rate on muzzle velocity, BC (supersonic and transonic), precision, even spin rate decay for various rifling profiles is tested experimentally.

Other sections detail the evolution of modern rifle, bullet, and optic design.

Results from extensive chronograph testing are presented which show the strengths and weaknesses of available commercial chronographs.

High tech instrumentation such as laser rangefinders and wind measurement devices are explained in detail by contributing author Nick Vitalbo.

The series is heavily based in experimental ballistics, and takes a sort of ‘mythbusters’ approach to many of the questions and problems faced by modern long range shooters.  In todays world of marketing hype and movie magic, Applied Ballistics continues to explore long range shooting using the scientific method, and publishes the results in a non-biased way that’s easily understood by the layman.

Future volumes are planned to cover the ongoing testing and evaluation activities of Applied Ballistics.

Steve Johnson

Founder and Dictator-In-Chief of TFB. A passionate gun owner, a shooting enthusiast and totally tacti-uncool. Favorite first date location: any gun range. Steve can be contacted here.


  • Bryan & Nick, thanks for being here!

    If you had to choose one rifle component to upgrade to improve accuracy, what would it be? Or in other words, whats the best use of money to improve accuracy?

    • Steve – First, I truly appreciate you having us here as part of this event. We’re very excited about the book and also to be here. We are looking forward to this event and think it will be a great opportunity for folks to discuss various topics with us.

      My answer here is going to be just a bit biased being a “laser guy.” Although it is not directly part of the rifle – my favorite piece of kit to improve accuracy is a good laser rangefinder. I most commonly shoot 0.308″ caliber weapons and try to reach out to 1000+ meters at unknown distances. Just a 1 meter error in range can shift my predicted point of impact +/- 0.05 mils. An error of 5 meters is on the order of 0.15 mils! That’s not acceptable to me, so a good laser rangefinder is my most valued piece of kit to increase accuracy.

      For handheld applications, I most often use a Vectronix PLRF 15 or Terrapin. I’ve personally used the new Bushnell Fusion 1 Mile ARC and like those a lot too.

      • I have the Bushnell also and I can sure vouch for it being a good piece of kit.

      • Thanks Nick. I am embarrassed to say I do not own one. I should and will get onto that. *Most* of my hunting is done at ranges where I have thought it did not matter, or I could estimate, but thinking about it now I have probably mis-estimated more times than I would like to admit.

    • In my opinion it’s a solidly mounted scope.

      Most shooters are more successful with a $500 rifle and $1500 glass than they would be with a $1500 rifle and $500 glass.

  • JumpIf NotZero

    I’ve taken long range instruction from multiple people. Among other contentions, I’ve been taught a few competing techniques.

    1. Wind. One guy says it matters from muzzle to target. Yes, you have the most speed and highest BC at the muzzle but a slight wind has more time to effect vs at the target where the power is low but time to effect is also low. This guy says to average it all together. 10mph at the muzzle and 0 at the target is 5mph. Another guy taught that wind only “practically” matters 2/3rd on the way to the target as that’s where the speed and BC are low and the time to be effected is higher. Which would you say is more accurate, ok to generalize?

    2. When practically shooting, do you guys factor anything but full, 1/2 and no value wind depending on direction? That is, would you factor 1/4 value wind? One instructor’s materials pushed for 1/4 value around 22degrees. Another instructor just said to make it 1/2 value. Thought on this as well?

    I’m sure I’ll have more as I’ve learned Kentucky windage, dialing and holds all from different people.

    • This is a loaded question! It’s one that very often comes up.

      1) First, I’m going to make the comment that ALL of the wind along the range to the target matters. You simply can’t ignore any of it – of course, right? That being said, for shots where the bullet is still supersonic where the bullet impacts the target, the greatest influence of the wind is from that which is closest to the shooter and not the target.

      For shots that start to reach the transonic and subsonic ranges, you’ll see that the influence of the wind is relatively flat until the point of transonic, it then momentarily increases, and drops off after that.

      It’s a bit tough to visualize this, so maybe a graph is best. This is something similar to what is in the “Wind Chapter” in Applied Ballistics for Long Range Shooting.

      (Check out the attached picture from this post to see the graph)…

      The blue line shows the relative influence of the wind at various points along the path for a 1000 meter shot with a 175 grain Sierra Matchking – real data. The red lines are ones that I just drew in there as estimates.

      The wind deflection for a given shot is the sum of the wind at the given range multiplied by the influence of the wind from this graph.

      As you can see, for a farther shot, you have a greater influence of the wind and where the wind matters along the path changes. As a general rule though, you can see that the beginning of the path is more heavily weighted – as a result – it is more important to get the wind correct in the beginning of the path rather than in the end of the path.

      2) When practically shooting, I personally only think of wind in terms of a pure crosswind. Once again, this is a bias here… when we do wind measurement experiments, we’re always breaking the wind into its individual components – a pure head/tail wind and a pure crosswind. From a ballistics standpoint, inside of any solver, the wind is broken into similar components as well.

      When you’re out on the range or hunting though, I usually use a Kestrel weather meter to get the wind speed and direction and then I look at the mirage down range to see the relative speed – once again – only really looking at the direct crosswind component though. I do a quick mental average between the two.

      If you talk to our other counterpart – Todd Hodnett – he’ll tell you that it’s extremely important to get the little shifts in direction correct. There are regularly 35-40 mph winds down there and so he’s been pushing us to add in :30 and :15 markers to the clock direction on all of our ballistics solvers. This is because at 35 mph, even small shifts in the wind change the effective full value crosswind quite a bit.

      Lesson here… if you can get wind direction and magnitude, use it and compute it to the greatest of your ability to figure out the exact crosswind component.

      Here’s a good chart on what to multiply by… This is from the AB Android App on the Google Play store.

      • JumpIf NotZero

        Excellent! I this AMA is going to do well to sell books. I’ll have to think about my next question as this is a great opportunity.

  • Guys one question that always comes up when we talk about new calibers in military pistols or just new guns is the 10mm. Personally I view it as many do as being a niche round and not one companies should worry about including in a new gun or a round for a new military pistol.
    From a ballistic standpoint isn’t a 40 cal just about as good?

    • spadesof

      10mm is a 40 cal.

    • michaeljball

      Ill add to this. On paper I like 9×23 winchester. Same capacity as 9mm and more muzzle energy than .357 sig. I think the mil couldeasily “standardize” another caliber. With “mainstream” handgun rounds being limited to the big 3, how much room for improvement do you see given the limitations of current technology in the developement (or wider introduction) of a “new” caliber? Can we and should we do better than 9mm, .40 and .45?

      Thanks guys


  • Thomas Gomez

    Bryan and Nick…thank you for being an awesome resource and thanks for all of your contributions to the long range shooting community.

    My questions. What is the best way to measure velocity? What do you think of the MagnetoSpeed chronograph?

    • JumpIf NotZero

      Follow up, are products magnetospeed and the Labradar (if it ever comes out) making the light/shadow based chronograph entirely obsolete?

      • The Magnetospeed is a good device. I prefer something like that over most optical measurement devices. With any type of variable light source, you end up with variable readings. Of course, the high end ones are pretty good and if you’re well acquainted with these devices and how to optimize results, then can definitely get good results.

        The Magnetospeed is a good device – of course you have to watch placement. I am personally excited about some of the new RADAR devices as well as the acoustic ones as they could be useful.

        That all being said, if you have good data for range, environmentals, etc. you can easily derive the muzzle velocity from the drop of the bullet at range. Just make sure you do it at a range at or near the transonic point – too close in and your own observational error is too large and could skew your results.

        • Thomas Gomez

          Thank you Sir.

    • The new book has a comprehensive chronograph review in which groups are fired over numerous chronos and results compared. In short, the magneto speed is very accurate and precise. I don’t hesitate to use it for serious testing in locations which prevent set up of the larger optical (Oehler) units. We did see some sensitivity to placement; you want it as close to the bore line as possible without damaging it.

  • Thomas Gomez

    Bryan and Nick. In regards to glass.

    What brand of glass is sitting atop your “go to rifle” right now? What is the most reliable optic currently on the market? What are your thoughts on the LaRue Tactical QD Mounts?

    • For me it’s Nightforce. I’ll admit that I have little experience with other high end optics (once I got familiar with NF I didn’t have any reason to look elsewhere).

      I use the LaRue QD mount on my OBR and have noticed only minor zero shifts which may be due to the rifle or mounts. Groups are great but zero can wander +/- a click or two in any direction.

    • I have a Leupold 3-18x mounted atop my OBR. It’s the 14.5″ version, so the short 3-18x looks great on there. Otherwise, I have the S&B 5-25x on top of the AI PSR. Both are great optics. I would say I like the Leupold more, just because it’s small, lightweight, and has great optical quality. The S&B is great too but I love the small size of the Leupold. I shoot Horus reticles in them only, so I am usually not moving turrets.

      • iksnilol

        Hope I am not sidetracking here but what do you think about the PSO, POSP and similar scopes?

        I personally like them (the chevron is easy to aim with) but I dont see any scopes with a reticle like that so I assume most people don’t like them. Also if you know about scopes with similar reticles please tell me.

        • I am not very familiar with these.

          • iksnilol

            Oh, that’s a bit awkward. Well I would recommend them then again I do like chevron reticles since I find them easy to aim with. They aren’t really made for target shooting but are good for accurate shots at longer ranges.

      • JumpIf NotZero

        Mark6? I just ordered one of those. TMR reticle, I’ll follow up a question later today about Horus reticles if you guys are still answering.

      • Thomas Gomez

        Thank you Gentleman. I am using a Bushnell HDMR with the Horus H59 reticle. I absolutely love the H59 reticle.

  • Bryan,

    To the extent that you are able to answer, how would you characterize the effects of modern rifle enhancements (optics, etc) on the individual weapon in the (both battle- and hunting-) field? I have no personal experience in the former, but have heard several different things, some of which jive with what I think I know and some that don’t, and fairly average experience in the latter.

    • broad question, but here’s my answer.

      Many of the ‘modern advancements’ (weapon mounted LRF’s & ballistic computers with sensors, night vision, etc) don’t necessarily increase the range that you can hit a given sized target, but they do other things which are very important to effectiveness. Most importantly, reduce time to engage.

      Rather than handling multiple devices and transcribing information from a kestrel to a pda, then to the scope, etc, you can do everything without coming out of the scope which reduces time to engage by multiples.

      Additionally, you can engage targets in more conditions (wind, dark, rain, etc).

      In summary, it’s not so much pushing the effective range from 800m to 1200m, but enabling faster and more reliable hits on 800m targets in all conditions.

      • Thank you, Bryan, that is pretty close to the answer I expected!

  • JumpIf NotZero

    Which one of you has the Jeep?

    • Ha.. the Jeep is mine.

      • JumpIf NotZero

        I know those sound bar / roll bars anywhere.

  • JumpIf NotZero

    Cold Bore. Have you guys scientifically determined cold bore shots to be a real and repeatable thing? One of the classes I’ve taken implied casually that cold bore MAY be more myth than reality, the actual effect coming from a Cold Shooter. That is, the very nature the most people will just pull their first shot after a long period of not shooting.

    I sort of dig this as the actual temperature changes after one shot do seem to be a far smaller delta than say after a string of 20 shots. If cold bore deviation was really because of the bore temperature, wouldn’t it be reasonable to assume that Hot Bore shots would impact with greater deviation?

    • I think multiple effects can contribute to ‘cold bore’ fliers including the temperature and state of fouling in the barrel, as well as the shooter and rifle not being ‘settled’ on the first shot compared to the second. I don’t think there’s any one effect that governs ‘cold bore’ effects. This is where good observation and note keeping comes into play; know your rifle.

      • JumpIf NotZero

        Putting a barrel away unfouled I can certainly see. As to that, I take you guys put a fouling shot down your barrels after cleaning?

        I know my cleaning has become a mostly bore-snake thing until I start to see issues then it’s just a quick patch and go again.

  • Steve Truffer

    9mm or .45?

  • JumpIf NotZero

    Scope Trends There has been an explosion of more advanced/technical optic products in the past 5-10 years than I would guess any time in history. What trends do you see staying and becoming more popular (zero stop, illumination, mil/mil reticles and turrets) and what do you see fading away or at least becoming less popular (38oz+ scopes, BDCs? 2nd rotation indicators, SFP, whole-mil-spaced-horus-like reticles, ???)

    Where do you see the next 2-4 years of “tactical” or long range precision hunter optics going?

    What in your opinions are the “next big things”?

    • I think you’ll start to see some level of integrated displays into scopes next. I expect to see an explosion of rifle-mounted laser rangefinders as well and then logically, ballistics calculators. There are significant advantages to having the LRF co-aligned with your riflescope for fast target engagements. If you couple that directly with an accurate ballistics solution, you can get rounds on target FAST.

      In that case, you’re not dialing turrets as much and instead shooting something like the H59 or the TREMOR 2 becomes the go-to approach. And if you have an integrated display, you can either draw a disturbed reticle or you can just give the elevation and windage markers for holding on the right place in the reticle.

      As an example, I know it’s not out yet… but the speed with which you can get an accurate range to target with the RAPTAR-M with integrated ballistics is at least 4-5 times faster than using a handheld LRF, then getting on your weapon and taking the shot. If you couple that with a Horus reticle, it’s definitely quick to get rounds on target.

  • JumpIf NotZero

    Bushnell Elite 1 Mile ARC vs Zeiss PRF vs Leica 1600 for practical long range and competition at 0-1000y? (Not all of us are going to drop 2-25gr on a Vectronix 😉

    • I haven’t tested all of them (other than the Bushnell) but I have heard many good things about each of them.

      Short of having all 3 on hand, here’s what to look at in the specs…

      1) Take a look first at beam divergence. This is the first thing I pay attention to. Let’s say it’s 2 mils and a circular beam. At 1000 meters, that beam will be 2 meters in diameter. Which means if you’re hitting IPSC sized targets then most of the beam is not going to hit the target, which means you might have a tough time getting an accurate range. So… first, look for small beam divergence.

      2) Next, take a look at what the range that they specify is and what the reflectivity of the target is when they did the spec. A lot of manufacturers will do it at 30% or something.

      By looking at those two things, you should be able to figure out where each of these LRFs is going to start to break down.

      Each of these systems does different signal processing in order to gain signal to noise ratio too. So, read up… maybe look around the web and see what some other folks have to say about them.

  • ABeiruty

    Will Smart scopes, digital or traditional optical scope plus integrated Ballistic computers with On-Screen-Display, be more prolific at a price where the average long shooter can afford?

    • If you take a look at the major cost drivers in any of these systems, it is two fold:

      1) The laser rangefinder
      2) The integrated display

      If you’re doing the LRF at 905, you need large apertures in order to get enough light back from the target. If you’re doing it at 1550, you’re talking military only due to ITAR restrictions.

      On the displays… the primary difference between say the new S&B scope and the traditional heads up display is that a beam combiner is used to project the head’s up display rather than an in-line LCD or other mechanism.

      The primary difference here is that most in-line LCD’s throw away 50% of the light due to the polarizers. In the case of the beam combiner method, you can get a much higher optical transmission. However, that beam combiner comes at a price, as well as the high resolution display.

      The other part is that you have to drive the brightness of the display extremely high in order to overcome daylight.

      These are all the major drivers here but I know that many companies are working on such tech.

      In the case of the all-digital approach, the real issue that I have with all of the systems out there is dynamic range. Quite simply, your eye has a much greater dynamic range and resolution than most of these digital systems. As a result, the images appear washed out and such.

      In the past, we tried things like adaptive contrast enhancement and even real-time HDR imagery. In the end, nothing beats your eyes… It’ll be a little while before camera tech catches up but since it’s being fueled by the cell phone companies, the rate at which this stuff is being improved is huge.

      • Side question: How do 905 and 1550 wavelength compare in terms of performance?

        • It’s less about performance of the actual lasers and more about how much power you can put out. At 1550nm, you can put out over 10x more power on average than you can with 905 nm. I go into some detail as to why in the book, but basically, you’ll blind someone if you put out that much energy at 905! Therefore, if you do a 1550 LRF, you can put out tons more power and effectively get a greater ranging capability.

  • JumpIf NotZero

    Follow Through Maybe you guys can clear this up for me… While taking a semi-auto long range class I watched 9 AR-15 shooters do well enough, and 3 shooters with 7.62 AR-10 platforms just completely fall apart. This was contributed to follow-through. Something that the AR-10s are particularly suseptible to because of their potential to unlock early. The proposed solution was a stiffer spring and heavier buffer. This was noted to be true even for the M110.

    My issue with this is two fold… One, shouldn’t the bullet be long gone before anything in the action even has a chance to move? Esp on a DI platform. And Two, if the action is unlocking early, shouldn’t this be a repeatable change?

    My thoughts on the matter have been that follow-through while instructed to be a proceedure that one employs AFTER the shot, is actually a mental/psycological check to ensure that the shooter is actually doing their part UP TO and AT the shot itself. That is, if you tell someone to hold the position after the shot, they are less likely to give it up that instant just BEFORE the shot, how ever subconscious that may be.

    Applying this to the weak shooter performance with the AR-10 guns specifically, perhaps the increased noise and recoil are harder to train for mentally? Instructing follow-through forces the user to avoid these issues by instructing them to focus on doing something (or that is, not doing anything) after the shot, while in reality the bullet has long since been on it’s way to the target.

    Make sense?

    • That is interesting because my precision rifle that I shoot is a LR308 (AR10 platform) in 308. Its actually a 1/2min gun all day long, and can do better under the right conditions.

      I have been shooting it for over a year, had nothing but good shooting. Had several others shoot it as well, and all of them have done well with it. I would be interested to see their take on your question as well, because on the flip side I see people at the range with their precision AR10 platforms, and have seen the same things you have.

    • gas guns aren’t where the majority of my experience is, but I can tell you for match rifles, the pressures on the rifle affect POI as well as follow thru. Cheek pressure, grip pressure, etc. will affect how the rifle moves during the time the bullet is in the barrel. Consistency is everything.

  • GarinEtch

    I’m an IPSC/3-gun guy wanting to take the plunge into long range rifle shooting. In the past couple weeks I’ve been 100% convinced that I needed to get a .308, then a .270, then it was 7mm, then 6.5 creedmoor…it’s exhausting. If you had to pick just one cartridge for everything past AR range what would it be?

    • Everything *past* AR range…
      338. Either Lapua Mag or Edge. Get the 300 grain Hybrid going ~2700 or 2800 fps and you’re golden.

      Alternatively, a 300 Norma with 230 grain Hybrids.

      • iksnilol

        You could also go for .50 BMG.

        Milsurp ammo is reloadable and relatively cheap.

        Or you can be boring and go for .260 or 6.5×55 and stick to 1km (+/- 200 meters),

  • JumpIf NotZero

    iPhone/IOS Seriously… why won’t you guys take my money!?

    • I swear it’s on the way… it’s been a long time in development now and it’s nearly complete. We’ve been through a number of BETA tests and want to make sure that it is not only feature complete but also has a minimal number of bugs or glitches.

  • michaeljball

    Can you explain the concept of over stabilization (if there is such a thing)? Why go with 1:8 twist rather than 1:7 for example?

    What could be done to improve velocities of conventional ammunition? Why not use faster burning powder and projectiles built to withstand it? What are some design limitations in trying to do this?

    I’ve heard some rounds yaw for a distance after leaving the barrel before stabilizing, what causes this if it is in fact a real phenomenon?

    Thanks again


    • Steve Truffer

      tighter twist means higher pressure & more wear on the barrel. can also cause issues with thinner jackets. The .220 swift was known to have issues early on because of this.

      • michaeljball

        I get that, but I am curious about over-stabilization as it relates to external and terminal performance.

        • Steve Truffer

          Can’t say on over stabilization, but faster powder means higher chamber pressure. Sure, you could made a round that peaks at 140KPSI, but your barrel and action would need to be ludicrously massive.

          The destabilization can come from rounds being at the verge of stability at the muzzle. Stability is all About RPMs vs length. If we have a given velocity envelope, but need more stability, we usually tighten the twist rate. However, we can also up the RPM count by increasing velocity, which can make the difference.

          On the flip side of the coin, as speed decreases, so do the RPMs. If a bullet has marginal stability out of the gate, the velocity loss 600 yards downrange could mean that is no longer has an acceptable rotation to length ratio. Berger bullets has a handy calculator for determining stability with a variety of variables

    • Good questions Mike!

      Regarding over-stabilization; the ‘common knowledge’ that you hear often is that a bullet which is spun too fast will not trace with the trajectory, in other words, it will point ‘nose high’ on the downrange leg of the trajectory, thereby causing extra drag and lowering BC.
      This explanation comes from high angle artillery shells which are far more massive, fly to very high altitudes (thin air) and arc thru dramatic angles over their trajectories. On this scale, it’s true that spin stabilized projectiles can fail to ‘trace’ and fall belly or base first.
      However, in the realm of small arms ballistics which usually occur below 10,000 feet ASL, projectiles weight less than 1 pound, and trajectories typically only arc a couple degrees (120 MOA) max, the flight dynamics are very different.
      Spinning a bullet faster has the effect of increasing spin drift, but not increasing drag. In fact, over stabilizing (I prefer the term ‘super stabilizing’) can have the effect of suppressing the limit cycle yaw angle of the bullet, and cause it to fly with a higher BC over long range. This is a major subject in the new book and you can read much more detail there.
      One caveat is that if you have a high velocity varmint round, over spinning might lead to bullet failure. But if you’re dealing with larger calibers and velocities closer to 3000 fps than 4000 fps, spinning a little faster typically won’t cause structural issues.

      Increasing velocities. I’m not a powder expert, but I believe that modern powders are sort of at a limit wrt energetics, and they would need fundamentally new/different chemicals to significantly increase velocity. But consider the other limitations such as bullet survivability and barrel wear. As it is now, the upper limits of powder, bullet and barrel are sort of matched and if powder takes a quantum leap forward, multiple weak links appear.

      Finally, launch dynamics such as barrel whip and muzzle blast can induce yaw at the muzzle. For a bullet that has adequate stability, the yaw typically dampens quickly with little adverse effect.

      • michaeljball

        Thanks for the great answers.

        I figured as much as far as more energy dense propelents go. I figure the extra weight on a crew served weapon that is expending high volumes of ammunition may be fair in trade for the ammo weight savings.


      • Interesting; then you contend that the effects of precession on a superstabilized small arms projectile is minimal?

        That wouldn’t be the first time that scaling effects made small arms ballistics diverge significantly from that of larger artillery.

  • Lance

    What do you prefer in 9x19mm 124gr or 147gr? I myself am a stern fan of 147gr and think most 9mm issue are resolved when using 147gr ammo.

  • JumpIf NotZero

    Caseless Ammo Have you guys been following the emergence of caseless ammo in developing firearms like the LSAT? In long range consistency is everything, do you ever see a scenario where such ammo makes it’s way into precision applications?

    • Personally I have not… Bryan might be able to follow up.

  • NotoriousAPP

    What statistical software package(s) are you using to design and analyze your experiments? JMP, R? ….please tell me it’s not Minitab.

    What models or platforms do you find to be the most relevant for your work?

    • Mostly Matlab, Python with Numpy, Scipy, and Matplotlib. You will notice that we have been able to embed some of the scripts directly into the website for the WEZ analysis and also into our AB Analytics app. In that respect, Python with those extensions is a great tool. Matlab is still the go to app for desktop work for us though.

      • Big Python/Scipy fan here. Matlab is to expensive for my amateur needs. I have my eye on Julia which is shaping up to be a decent competitor to Matlab, *Py and R

  • M.E. Prof

    If a young person wants to get into the firearms industry, what would you tell them to do to get there?

    What can schools (universities in particular) do to help supply this industry with qualified engineers?

    • My path involved the standard aerospace engineering degree from Penn State, while remaining active in the firearms industry as a competitor.

      Learn engineering, and also network with industry people and keep an eye out for opportunities as an active shooter.

      • Ironically, Bryan and I are both PA guys and went to school near each other – Bucknell University for me.

        Totally agree with Bryan – get an engineering degree. Doing mechanical engineering and/or aerospace engineering will get you a long way in the firearms industry. My background is in electronics, lasers, and software, which is atypical for this industry.

        However, as you are seeing, there are increasing trends toward integrated devices like displays, lasers, ballistics, sensors, etc into riflescopes and optics. For that, having a background in electrical engineering and/or computer engineering and software can go a long way.

        • JumpIf NotZero

          Well, at least you guys didn’t get stuck at ESU 😉

  • Thomas Gomez

    Bryan….Have you ever taken a 210 or 230 .30 caliber Berger bullet out to a mile from a .308/7.62×51? Any tips for loading the 300 WSM with the 230 grain Berger?

  • Scorpy

    Tips for long-range shooting with a .308? Best effort so far has been an IPSC-sized target (60 cm falling plate) at 680 meters, with some wind and a spotter. Didn’t get to try 750 or further due to time running out. I was shooting a bit high (~1 mrad) compared to my trajectory tables, velocity seems roughly correct based on 100 m => 300 m impact difference and quick measurements in field conditions. Could recoil and rifle support have an effect, a friend suggested the stock was slipping?

    185 gr Lapua Scenar seems a bit slow, shooting from a 22.4″, 1:12″ twist barrel. 167 or 155 grains seem to work better based on Quicktarget results. What would be the rough maximum range for those loads?

    What would you recommend optics-wise for long-range work at a budget? I have a Leupold Mk4 16×40, but working mil-dot with MOA adjustments is a bit of a headache, plus the mil-dots have some limits for long-range work. Lasers would ofc help with ranging, but sometimes that’s not an option for me (same goes for using GPS for navigation). A high-end Vortex could be a suitable replacement?

    • In long range shooting, it all comes down to controlling your unknowns and variables. In fact, Dan Periard (another guy on the team) recently wrote a short article on this. Here’s a direct link to the article:

      Here’s what I’d recommend…

      1) Good LRF – Or like you said, a GPS with a decent range measurement that is +/-5 meters at the worst.

      2) A good weather meter. I have always preferred the Kestrel devices even before I started working with them directly. One of the reasons is the exposed temperature sensor. With good temp and good pressure, you can save yourselves a lot of headaches.

      I am not sure if you were running live calculations when you were out, but it’s critical to nail range, temp, and pressure. Wind can influence your vertical component via aerodynamic jump. You probably weren’t seeing much effect of Coriolis at that range.

      The last thing might be your muzzle velocity… If you were not totally confident in your load, then you might be running a bit high or low compared to what you though. You’re still well into the supersonic for a 308 at those ranges. Relying on data from 100 and 300 meters though is going to be pretty tough though because even a small difference in your drop at 300 meters could mean a relatively large difference in muzzle velocity.

      On the optics side – If you can afford something in the $1500 range, the Bushnell HDMR has made some waves and I’ve heard some good things about it. I have not shot it personally but a lot of guys that I know have and seem to have said good things about it. Working MOA/MILS could be a nightmare on the same scope. I have no idea who ever came up with that concept – being an engineer, mixing units on a scope would drive me crazy!

      • Scorpy

        Training to be an engineer here, too! The thing about LRFs and GPSs are that we’re trained not to rely on them – quite a few stages on our sniper competitions strictly forbid them, and usually stress limited round counts (e.g. 2 shots max, maximum points only for first-round hit); ergo, the mindset about them over here is a bit mixed.

        During the course, we ranged our targets with optics (working in pairs), fired a few rounds, adjusted, and if we had issues, called out for the instructors and asked for the true range. Fairly big course, some 20-30 shooters, and a limited amount of instructors. 1st day was mostly useless for me, lost all faith in my rifle, but one the 2nd day me and my partner managed to work it out. Could’ve tried my hands on a .338 out to 1400, maybe the next time.

        Funny, I always found Bushnell a bit of an air rifle, maybe .22 brand (that’s what my Bushnell is suited for, anyways). Seen a fair few Vortexes, esp. the 4-16×50 FFPs over here, plus they’re readily available.

    • what Nick said, plus, once you’ve developed an accurate load, don’t change anything. Load it all the same and work on shooting/practice. Knowing your equipment is very important and changing things makes that hard.

  • finnsniper

    Why silencer changes impact point of the bullet? Why some silencers add accuracy and some totally ruin it?

    • Putting a suppressor on changes the dynamics of the barrel/weapon and the exit of the bullet. Putting a weight onto the end of your barrel should cause a POI shift downward. Accuracy is going to be dependent upon the design of the suppressor and how it’s managing the exit of the gasses.

      • Matt

        Done any testing with the eccentric Osprey silencers? (for sub loads like .300 BLK)

  • winnie

    does a AR platform for military sniping use need to stay at the 308 or do you think they will look into a larger caliber system/or a modular one?

    • I haven’t seen any movement toward a larger caliber. I wouldn’t be surprised to see a smaller caliber though with a higher muzzle velocity. I’ve some guys converting their OBRs over to 260 and pushing out higher MV.

      • I agree with Nick; smaller caliber, probably 6.5mm.

        The idea here is you can get a higher BC bullet (130 grain 6.5mm) at a higher MV compared to a .308. Everything is higher performance with the possible exception of KE.

        Also interesting that at the mag length constraint of 2.800″, you can seat a (proportionally) longer 6mm or 6.5mm bullet to that constraint.

        There is a section specifically about this in the new book: optimizing AR’s for ballistic performance.

  • iksnilol

    How effective are pistol rounds with spitzer bullets at distance compared to regular ball (non spitzer)? As in if you load a 7.62×25 with a rifle bullet (I.E 123 grain AK bullet). I know AK bullets aren’t the most aerofynamic but they should have higher BC than regular pistol (ball) pistol bullets.

    Granted, the above example doesn’t mention OAL cartridge length and the like but it’s hypothetical.

    • obviously, pointy bullets will have less drag than blunt bullets. However, at low (pistol) velocities, bullet shape is less important to drag than it is at high (rifle) velocities. For low speed stuff, hitting your target is more determined by velocity consistency (low ES and SD) than high BC.

  • John

    I have a simple question. How does a automatic case trimmer such as the Giraud affect accuracy?

    • The Giraud is a great tool and very effective at trimming and chamfering case mouths. The chamfering is very important because it allows you to seat the bullet without scaring it.

  • Matjaz

    Are there any plans to add dope card format to your Ballistic Calculator on AB website , current range card is great but not too practical for tactical comps

    Applied Ballistics

    • We have talked a bit about this to do DA – corrected cards. We haven’t initiated the project but we’ve discussed how we’ll do it. We’ll keep you posted if we do kick it off.

  • Bloedman

    How can we keep the advances you make out of the hands of our enemies?

    • There is a whole other side to AB/nVisti that no one really knows about. Most of the best tech that we have is not at all public and not discussed online or on forums.

      All of the advanced tech, like the RAPTAR-M, for example, or our IBEAM device is strictly ITAR controlled. There is other higher tech stuff that we have been working on too that is not public and will likely remain that way for a long time.


    Bryan, let me start by thanking you for writing such great books on long range shooting. Your books are never more than a few feet from me and I reference them all the time. Concerning Ballistics Solvers there has been all kinds of debates on G1 vs. G7 but I see in your apps you have Custom Drag Curves. From reading your books I am tracking on how the G1 and G7 drag models are representations of the drag profile for a very specific geometry or form factor bullet and that neither is really incorrect they are just often miss applied. Meaning you should use the drag model that is the best representation of the bullet you are shooting. With that said most modern boat tail bullets more closely represented by the G7 drag model. But now you have this custom curve added to your app. IF what I am understanding is correct these custom curves are not like a G1 or G7 in that they are using a BC modifier to compare the form factor of your bullet to the standard form factors of the G1 or G7 standards. My question, is this assumption correct, are these custom drag curves the actual drag profile of the bullets. I know from using them with my bullets in the apps they are wicked accurate at predicting my dope. Would you explain this a little more how is this working behind the scenes. A quick note where I have seen the these custom curves having the greatest increases in accuracy of the prediction is when I am shooting at extreme ranges normally into transonic and even supersonic velocities. Please expound on this new feature, I am sold on them but do not fully understand why they work better!

    • you actually seem to have a very good understanding; BC’s reference standard drag curves, typically either G1 or G7. The fit for modern long range bullets is better with G7, but there can still be some minor mismatch, which is worse in the transonic range. Custom drag models represent the drag of each individual bullet, so you don’t suffer from an imperfect match, rather you’re modeling the actual drag. Since G7 matches well thru supersonic, you won’t see much difference between G7 BC’s and custom curves in that range, but at transonic the difference/error is greater.

  • phill

    Anymore news on the lwrci and colt merger. On the lwrc forum they said Darren the president stepped down and a guy from colt took over.

    • Sorry Phill… I don’t have any insight here.

  • Scott Whitehead

    I’m curious why the concept of absolute station pressure is not used more in long distance shooting. Everyone wants to use barometric pressure and altitude, and that just seems like twice as much work, with two components to determine, document, and track. Is there any reason for this? And second, It seems like the easiest way is to use Density / Altitude (since it also compensates for temperature) but I can’t find a D/A chart or formula that converts Station Pressure and Temperature to Density Altitude. most convert altitude and temperature (apparently assuming some barometric pressure) to D/A. Any hints here?

    • The only reason I can think of is that it’s more accessible from weather stations. I know that when I was implementing a few features on the Android application, like pulling information from OpenWeatherMap, it reports barometric pressure. If I wanted to get station pressure, I had to know the current altitude or the altitude of the weather station, which is not reported, then convert it myself.

      This is pretty much the same all over from what I’ve seen from nearly every weather service. So unless you have a handheld device or something like the Casio barometer watch, then you’re stuck looking at your smartphone or the web for a report of the barometric pressure.

      On the DA conversions, the Wikipedia article is good:

      You could make yourself a spreadsheet to do it. The National Weather Service equation is really simple.

      As a side note – most Android phones now have pressure sensors built into them and you can pull station pressure directly from the internal sensors. Typically, it’s used to aid in the GPS altitude readings since Altitude has the largest error source in the GPS signalling.

  • iksnilol

    How accurate are BDC reticles in regards to temperature and air pressure? I mean will things like using ACOGs in different climates throw your shot off if you use the holdovers?

    • All depends on how far off you are from the conditions on which the BDC was created. Best thing to do is run a ballistics calculator on those conditions and compare them against your current conditions / bullet and you can figure out what the delta would be. Kind of like what I wrote above with respect to what LRDUDE posted.


    BDC has some utility if you are shooting flat trajectory rounds and stay confined to short ranges. check out Nightforce’s Velocity Calculator their velocity reticles are BDC and their calculator shows what happens when they are off condition from the atmospherics they were designed on. pretty compelling why BDC is a bad idea for long range if you don’t have a means of correcting for the new air density.

    • Along these lines – you can back-calculate what the actual drop is at your current DA if you know what the BDC was designed for…

      Let’s say you have a BDC designed for a M855 at sea level and standard atmospheric pressure running 3000 fps. Run a table on your ballistics calculator (AB web site or other) and figure out what the drop is at the yardage markers… Those are going to correspond to some number of MILS or MOA, whatever you want your point of reference to be.

      Now, with a ballistics calculator, run your current bullet / gun and atmospheric conditions. Print out a range card. Look at the yardage markers where it crosses those points you’ve written down.

      You’ll probably have to run the range card in 2-5 meter increments to do this.

      It’s a real pain to do, but it’s a means of using a BDC if that’s all you have and you can shoot different calibers, MV, etc.

  • Matt

    I loved your book on external ballistics. What book or resource would you recomend for internal ballistics?


    Very Cool, I went thru one of Todd Hodnett’s courses and he showed how to take a BDC and reference it to target laid out in 1 ” squares, another in MOA and or a milliradian based target. He just converted the BDC sub tensions to MOA or Mils making them universal for use like a mil-dot reticle. He likewise showed us how to take that information and make DA based range cards with holds then for each of the sub tensions. Pretty Bad Ass for the ACOG and other BDC reticles. We didn’t have to know what they were designed for we just referenced them to a universal angular unit of measure. still way better to just have a milliradian based reticle. I also saw out at the last shot show Todd is working with you guys now. pretty cool kind of the dream team for shooting stuff at long range.

    • Yep… been working with Todd for years! We were finally able to make it official. If you’ve been there then you undoubtedly know where these photos were taken!

      • LRDUDE

        Good memories, that is the Golf Course looking down from a narrow ridge on top of a big hill. You can even see one of he head targets in the bend of the corner of the road. The road going off to the right goes behind the hill and the hill where it looks like the photo came from has the road you see on the south side and the road running off to the right going on the North side of the hill. The golf course and wind courses are truly humbling. we never got under 20 mph wind and it definitely let us know we weren’t in Kansas anymore. Very Cool you guys are all working together I know he is the best instructor I have ever had and now you guys have the science to meld with it all. Wish I still had a reason to get out to the ranch good people, awesome facility, and we all learned more than most people can absorb in a life time.

      • LRDUDE

        PS. I got to hear the Brief you gave on the original One-Shot program at Shot 2010 maybe 2009 can’t remember which year exactly, you know how shot gets with the rhino visits, but it was at the JSOP Conference. Very impressive technologies if they ever get fully miniaturized and weaponized.

        • Ha! Glad you got to see some of the inside story then. Pretty cool – I think people just liked the fact that I brought donuts and red bull to the meeting. From then on out, I always make sure to have at least red bull on hand for any meetings. This material can get tedious. When I start talking about lasers and stuff, people start drifting!

      • LRDUDE

        The stake house in town, awesome bread pudding and medallions

  • Chance

    At what range does the Coriolis effect generally become an issue? Does the Coriolis effect’s… effects differ depending on what cardinal direction you’re facing? What would you say are some / the most common myths with regards to optics, long-range shooting, et cetera? How do you quantifiably consider the effects of rain, snow or other precipitation?

    Also, why did the book take so long to come out on Kindle?

    • My general rule is that if I’m shooting in the supersonic ranges of the bullet, I don’t always think about Coriolis. If I’m into the transonic and subsonic I do. That’s a personal opinion and Bryan may have some other thoughts on this one.

      Effects from rain,snow, etc are not really very quantifiable. Higher humidity drops the air density.

      • It all depends on how accurate your rifle is, and the size of your target. If you’re shooting a 1 MOA rifle at elk, you can ignore coriolis beyond 1000 yards. But if you’re shooting a 1/4 MOA varmint rig at 2″ wide prarie dogs, you might miss at 400 yards due to coriolis. It just all depends. There’s a chapter in “Accuracy and Precision for Long Range Shooting” which specifically addresses this question with WEZ (hit %) analysis.

  • Peyton Besand

    I have had an interest about getting into long range shooting for a while, sadly, my funds are not sufficient enough to purchase quality equipment and I won’t spend my money on fill-in equipment. I have been looking at riflescopes though, more specifically reticles. I know that first focal plane is a must, but is there any reticle out there that, in your opinion, just shines at what it is meant to do?

    • LRDUDE

      Check out the Tremor 2 the wind dots built into the reticle solve a great deal of wind management issues. The dots being based on TOF allow them to be scaled to any TOF for any weapon and ammunition combination. Once you know what each dot represents in mph of wind for your rig you simply make your wind call and hold the appropriate dot. Best overall system I personally have ever seen in a reticle. The vertical stadia are all milliradian based. Another advantage is with the wind dots you have a wind bracketing system in your field of view. Bracketing wind is the best management policy I know of. hopefully Nick can replay he is the wind guru. I know he got to spend many millions of us tax payers money on research and development of wind measuring systems for sniper applications. I doubt anyone on the planet has spent this kind of coin concerning wind research and development for small arms target engagement.

    • The Tremor reticle, developed by Todd Hodnett, is the state of the art.

  • Allen

    Hi Im from New Zealand and was wanting to know the g7 bc for a 7mm 140gn Nosler balistic tip? I know the g1 is .485, I only shoot to 600yds, is there much difference on paper or on animal within 600yds with using either bc? Thanks

    • Easiest way to convert is multiply the G1 BC by 0.512. In this case, it would be 0.485 * 0.512 = 0.248.

      If you’re only shooting to 600 yards, you’re unlikely going to notice any difference in the estimated drop as the round is still in the supersonic region there.

  • Joe

    Whats a good affordable rifle and scope if someone wants to get into long range shooting? I work at a range and people ask this all the time. i’m a fan of Tikka/Sako and Vortex. What do you guys think?

    • Scott Whitehead

      I’d strongly recommend the SWFA 10x SS as an affordable entry-level fixed-mag Mrad/Mrad scope. It’s a fantastic piece of glass for under $300 (Rear Focus model), and it will be a while before you need more. I’ve competed rather successfully (placing top third in major national level long-distance tactical matches) with this glass. Is it optimal – certainly not, but it’s an easy thing to upgrade later. I chose to put my money into action / barrel / chassis initially, but I know others will have a different opinion. Just my $0.02

  • George Crawford

    What are the optimal chamber dimensions for the 215 hybrid in 308 Winchester for FTR competition?

    • The most important chamber dimension is the throat; you want around 0.225″ for the 215’s. This will also allow you to seat the 185 LRBT. The 185 seats way long, but does offer an alternative in that same chamber.

  • Scott Whitehead

    Bryan & Nick- Thanks so much for your time today! What light can you shed on the “distance to lands” measurement? I understand how to measure it and set it, and it’s relationship to COAL, but I’m curious about it’s impact on performance parameters. This seems to be somewhat of a black-art trial & error parameter, and I’m wondering if there is some analytical method of determining an ideal measurement here. Or, put another way, if I have a load I’ve worked up that works for me, and I need to shorten the COAL by 0.030″ with no other changes, what performance differences should I expect? Is there a way to find the “ideal” distance to lands for my combination (6.5CM w/ 140gr Berger Hybrid, 42.5gr H4350, currently set at 2.900″ or 0.020″ to lands) and to know what penalties I will pay if I shorten the cartridge a bit for better magazine compatibility? Is there a specific number I should try?

    • the following are the only universal rules I know of on this topic, but most of it is rifle specific.

      Seating the bullet to jam into the riflings will cause pressure to spike a little beyond what it would be if you jump (even a little).

      Jumping more would lower pressure, until you significantly decrease internal powder capacity, then pressure can start to go back up.

      Bullets with tangent or hybrid ogives tend to be more forgiving (in terms of precision/groups) to jump distance, whereas VLD’s are very picky as to where there ‘sweet spot’ is.

      Other than that, you have to test in your rifle.

  • Scott Whitehead

    Bryan- Some time ago I read an article you wrote about the phenomenon many of us have seen of degraded accuracy in certain loads at short distances, and the accuracy actually improving at distance (when measured in angular units such as MOA, and independent of weather-related factors). In that article which I can no longer find, you ruled out several possible factors as being an order of magnitude less than the effect as it was noticed, and I think you came to the conclusion that it’s true root cause is unknown. Now, years later, I was wondering if you have any more insight into this, and any advice for shooters with good long range accuracy rifles / loads but who are fighting for short-range groupings. (And of course, I hope I’m accurately summarizing your paper – my apologies if I’ve mis-interpreted or mis-remembered it.)

    • Scott,

      Here’s the article you’re refering to:

      You summarized my conclusion well: I don’t know of a flight dynamic can cause this effect. I suspect poor parallax adjustment at close range is often the culprit.

      I’m actually studying this phenomemna right now. It’s my goal to sort it out and report in the next book in the “Modern Advancements” series. As of now I don’t have a solid answer yet.

  • Eddie

    First thank you for your time and expertise. My question is what is your load development process for 223 & 308, high level summary of course due to the format. How do you select brass, powder, primer, projectile, onto load testing (e.g. Optimal Charge Weight, Ladder, etc.) Thanks again in advance, Eddie

    • First, using the best components will eliminate many steps, mostly in brass prep. Start with Lapua or Norma brass, and load development is highly simplified.

      Next is to find a suitable powder for your cartridge/bullet weight. As long as you’re using a suitable powder, I don’t think it’s necessary to experiment with different powder types.

      Use match primers, I recommend CCI-BR’s or Federal match.

      Work up powder charge in 1.0 grain increments (1 shot each) until you see pressure signs, then load 3 grains below that.

      Now work on seating depth, this is my primary ‘knob’ for load development. If you have a mag length constraint, there’s not much room for adjustment here. Otherwise, start 0.015″ off the riflings and move back in at least 0.015″ steps, at least one 5 shot group at each.

      Using the above (roughly outlined) process, using good quality rifles and optics, I’ve rarely failed to achieve acceptable accuracy meaning what I consider the rifle to be capable of.

      Most of the trouble with load development is actually trouble caused by low quality rifles, optics, and components IMO. Use the good stuff and it’s easy.

      • Tantoco

        Thanks so much for your feedback Bryan, greatly, greatly appreciated! I think in the past I’ve focused too much time testing various charge weights (ala Optimal Charge Weight method) and not enough on seating depth, looking forward to applying this approach.

  • Just an FYI – on the load out questions, Bryan is going to hit those up later on this evening.

    • Eddie

      Thank you Nick. I’m trying to find it from earlier but I remember from this morning you had responded that laser range finders are your most important tool to invest in. I have a Swarovski Range Finder and have always wondered how this compared to the high end range finders, have you had any experience with it or feedback. Thank you.

      • Hi Eddie – Which model is it?

        • Tantoco

          The 8×30, thanks again Nick.

  • Russ

    From everything that I have read, the 55 grain M193 is superior in every way to our current NATO load, with the exception of penetration at longer ranges. Given the trend for shorter barrels, (14.5″) the performance difference becomes even more pronounced. However, there is a lot of more involved folks talking up the new M855A1 and are bestowing upon it some traits that are simply not credible to me (e.g. greater penetration than a 7.62 round, better “accuracy” etc.). What, if anything would add to the conversation?

  • Gene

    I don’t know if this is too late, but has there been any rigorous study of cryo treatments on receivers/bbl and it’s effect upon accuracy and precision?

  • GoldStarFather

    When shooting a solid, full bore projectile through a smooth bore barrel (shotgun) what, if any, effect does the transition from sub-sonic to super-sonic speed have on the projectile while it is still in barrel?

    Let’s say exit speed is 1300 fps. Is there any force upon the projectile or the barrel during this transition? Would or could that force affect stability when leaving the barrel that would affect accuracy? Would there be any advantages when a sabot is used?

    I have been reading as much literature as I can find on this subject but it is never addressed as far as the transition while in the barrel. I am hoping you could give me some insight.


    Nick and Bryan, I recently got turned on to the Applied Ballistics Analytics program. I likewise read your book. Accuracy and Precision where you explain WEZ which the Analytics program can perform several of the WEZ analysis you did in the book. I have to tell you the book and even more so the Analytics program has nearly totally changed how I look at engaging targets. It is a real eye opener to how things really work. I have to share an analysis I ran with your guys program because the results are so dramatic that I would really like you to explain how this is possible. I was comparing two weapons systems. One using M118LR ammo – 175 gr. SMk bullets and the other the Berger 230 gr. .30 cal hybrid match bullet. The comparison I was looking at was concerning all the hype about having super precision shooting rifles. I ran a 1/4 moa dispersion rifles shooting M118 against a 1.0 moa precision rifle shooting the 230 hyb. If I put even a small amount of uncertainty in the wind SD at long range the rifle shooting the 230 Hyb had a much higher hit probability. Trying to logically think about this how can a 1 moa weapon not only have a higher hit probability at long range but a significantly higher hit probability. This is completely contradictory to everything I and most anyone I know has been told or assumed for as long as I have been pulling triggers. IF this is true it changes everything. WInd uncertainty is something that is nearly impossible to get a grip on. The very best wind caller I have ever even heard of is a +/- 2 mph consistently and that is on a golf course type minimal terrain feature range. out in the real world of mountains, draws, thermals and all the influences we see out west shooting you are lucky to call wind within 3-4 mph. With all this said your program is indicating that the bullet selection is probably the most important thing to maximize in the entire system. BC is everything when it comes to dealing with the wind and the rifle’s accuracy is not irrelevant but it is way down on the peaking order of what is important when shooting long range and making first round hits. This defies nearly all logic, Am I doing something wrong with your guys program if not. Please explain how this can be. Also again the Applied Ballistics Analytics program is probably the most useful and powerful piece software I have ever used since I started using your ballistics solvers. In the future I would really like to see more of your books on proving how much of what we think is how things work is really FUBAR and BS that has just been passed on for so long that we all accept it as the truth. Anyway please tell me how my above conclusion can be possible or am I just all screwed up in what I am seeing and thinking.

    • That’s a pretty great observation that you have. You’re right though, shooting the 230 gr Hybrid, you’re nearly doubling your probability of hit.

      And thanks for the “props” on the software. There’s a lot of time and effort that went into that package. It’s very comprehensive as I am sure you have discovered.

      I made some assumptions and ran a similar analysis for the group here at 1000 meters. First, I assumed that the shooter can only read the wind to within +/- 3 mph, which is about what we’ve concluded through several tests with the military and civilian sectors.

      Assuming 2650 muzzle velocity for both bullets and also assuming each has an SD of 15 fps, the two plots are included.

      Even with the 0.25 moa gun shooting M118LR, the 230 Hybrid with a 1 moa gun is the clear winner here. Probability of hit is nearly double. Looking at a scattering of the bullets though through the simulation, it becomes pretty obvious as to why.

      It’s all about the wind!

      The time of flight for the M118LR in this case is about 1.98 seconds on the simulation and it’s 1.64 seconds on the 230 gr hybrid. With the greater time of flight, we would expect to see larger wind deflection.

      I love your idea of debunking things like this in a book. There are a few high level points we could hit on but there are any infinite number of situations that can be run. I’d encourage people to check out the software as you have and allow them to make their own discoveries too.

      • LRDUDE

        Thanks Nick I am glad I you are confirming what I was seeing. In the analysis I ran, I even scaled the MV relative to the grain weight increase of the 230 over the 175 smk the results were a little less compelling than what you are showing but it doesn’t change the fact that most of the world is all screwed up in how they look at the complete weapons systems when designed for long range shooting. Everything needs to start with the most optimal bullet and work backwards. We have all been chancing super precision shooting rifles for decades and come to find out we have all really been not wasting our time but not focusing on what is really important. From what you just confirmed and what I got from running the Analytics program. A long range shooter needs to focus on means and methods of managing, accessing and mitigating the wind above everything. A Walmart special rifle with the right bullet selection and a decent wind call is going to put more rounds on target than a $20K PSR weapons system shooting something like the 175 or 190 SMK. Why isn’t this kind of knowledge readily available we have all been not only wasting time and effort but huge amounts of money because we simply don’t understand what the real pecking order is for all the influences that effect hitting targets.
        Again thanks guys for putting out such a powerful piece of software, In my opinion it has more utility and meaningful applications than anything I have seen concerning engaging targets in the last 150 years. I am glad you guys are on our side this software is some major powerful shit! it rocks the core and proves or disproves how things really work. Money well spend even though expensive it just proved I have spent thousands of dollars chasing things that really don’t matter. Unreal eye opener. If I start another thread somewhere 100% about analytics would you guys be willing to seat in and just run analysis on questions. I know it is asking allot but the majority of the shooting community is walking around with a blind fold on including me for the past 25 years. This stuff has to get into the public awareness it is beyond a game changer. Just think about it, You should use analytics to realistically define your intended shooting application and with minimal deductive reasoning you know what you should build for a weapon, aspects you should train harder at mastering and it all gets summed up in means to quantify it all. HIT PROBABILITY it is what we are all really after !!!!! you guys have just empowered a totally new generation of better shooter purely because they make decisions that actually matter. I can’t tell you how big this is when you really think about it from every aspect. knowledge is power and this program can provide more knowledge in 5 min. than I have learned in 25 years pulling triggers. Awesome piece of must have kit !!!!

        • Thanks LRDUDE – I’m really glad we can help the community with this software. I can’t tell you how many times I’ve used it in training and discussions with people. The math really doesn’t lie and it’s really obvious when you start running analysis that people are spending tons of money on wasted efforts.

          If you’re worried about putting 10 rounds on a target in a 5 inch ring, then sure… you need 0.25 moa precision. But if you’re hunting or hitting man-sized steel, a 0.5 or even 1 moa gun is really good enough. You’re better off working on pushing up your muzzle velocity and running the right round… cutting down time of flight to increase your probability of hit.

  • strongarm

    It is said “Lever Delay Blowback” principle can not be explained through the drawings. Is there a short and reasonable explanation about what it is.

    Besides, Pedersen’s Lever Delay is also very intriquated. A short description about its working would be much appreciated.

    • strongarm

      correction; Pedersen’s Toggle Delay.

  • exoskeleton

    I recently did some research on monolithic bullets and
    design and tested my own. Do you think
    it is the future and what is your opinion on the driving bands that seems to
    become synonymous with these bullets, does increase accuracy or not?

    • Monolithic (lathe turned) bullet have the advantage of optimizing drag reduction beyond what conventional (copper cup/lead core) bullets are able to achieve. However, the density advantage goes to conventional bullets which is significant. In the end, the performance advantage is questionable but usually goes to lead core bullets, and cost always favors conventional (lead core). I don’t see a big shift towards monolithic bullets in the future. They’ve been around a long time; if they were dominant, it would have been demonstrated by now but it hasn’t.

      • exoskeleton

        I appreciate and agree with your reply. Thank you.

  • Dj 708

    Could you guys describe Coriolis effect, in a easy to understand way. I am not a scientist so most of the explanations are to technical for me to understand. Also any place you could point me to that would help me get a better understanding.

    • DJ – Here’s a fun video.

      Ignore the parts about the toilet flushes and go to 30 seconds in. It gives a nice explanation and a good visual.

  • LRCampos

    First, thank you for the books and the oportunity to answer our questions.
    My question is about precision and barrel wear: assuming that using two bullets (one 155gr and other 185gr. for example) at mid range (about 300 to 600 yards) that will have velocities thats causes them to drift almost the same on light/médium wind (say 10mph) is there any advantage on using one over other regarding precision and barrel wear?
    (I hope I could get the answer logic… english is not my primary language)

  • Andrew

    Nick & Bryan – When will the ABREM launch and what is the retail price? It seems like a good options for manually entering range data and getting a solution since the Storm & Rulr are really expensive.
    Also, what is meant by “Ballistic Calibration allows you to modify your solution to match observed impacts in the field.” as shown on the web site?

    • Andrew – REM is available – we are currently fulfilling military orders right now and once those are complete in the 6-8 week timeline, it will be available to civilians.

      It’s really simple to manually enter the range data with just scrolling up and down. I’d be willing to push out a user manual if you send me your email address. Just send me an email to:

  • Nomar Abdiel Vazquez Vazquez

    Which bullet is more accurate for long range shooting: 7.62x54R or 7.62×51 NATO ?

    • uisconfruzed

      What bullets & their BC, and twist rate?

      • Nomar Abdiel Vazquez Vazquez

        I’m just a neophyte, sir. lets just assume is regular surplus ammunition.

      • Nomar Abdiel Vazquez Vazquez

        I’m a neophyte in this matter. Lets say non match rounds, FMJ surplus.

  • Studenta ot Sofia


    What is the longest possible shell to stabilize through spin? 5.5 caliber lenght/diameter or?
    Is this one and the same for all calibers?

  • Eluoci

    What makes 6 -6.5 so more “accurate” Does its proportion to air density has anything to do with it in comparison to other diameter bullets? Or its just happens that 6.5 bullet are better made and have better coefficient? Just curious if proportion to anything density, speed, weight is a reason they are so accurate. Or if not what makes those calibers so accurate? I how you understand my question, sorry if its confusing.
    Best Regards

  • sickofthespin

    I’m trying to find the best 5.56/223 round, for long range shooting and self defense. Two that I’m looking at are the Winchester 69 grain Match (Sierra MatchKing bullets CE 0.297 / Velocity 3060 / ft. lbs. 1434) & Hornady 75 grain 5.56 NATO Superformance Match ( Velocity 2910 / ft. lbs. 1410). I looked at the Black Hills 77 grain NATO but the velocity and energy were low. I’m current using the Hornady 5.56 62 grain TAP. One of my problems is that I haven’t been able to find out how Hornady and Winchester get their ballistic results (Barrel Length). I also need to know if I would have pressure problems running the Winchester 69 grain & Hornady 77 grain 5.56 NATO Superformance, in my AR & M4 rifles.


    Nick and Bryan, thanks for helping us improve.

    Which of .204 Ruger, .222 Rem, .30-06, .308, .338 Federal, .300 Win Mag will give best long range performance? All are in 24″ barrels, (Kimber Classic, Remington 7, Remington 700, SAKO 75, Kimber Classic, and Tikka SubMOA, respectively), free floated, with Bushnell Elite 6300, 4.5 x 30 as scopes, all using NF Rings.
    And if one caliber best, what are recommendations for factory optimum load for best effect?

  • 1_Mitch

    I subscribe to four gun magazines. Each generally includes velocity Standard Deviation in their tables of gun/ammunition performance. Yet there does not seem to be any correlation between low SD and small group size. Often the smallest group average comes from the larger SD. So why is SD interesting?


  • Rodger Young

    I hear a lot about ‘overstabilized’ bullets. This being when the bullet is spun so fast that the centerline of the projectile does not follow the trajectory, the tip staying above the trajectory on the back end. Is there any truth to this?

  • Ronnie Schmidth

    Could you two fellow explain what a SEE event is? There’s a fellow claiming it basically boils down to a stuck bullet type of failure. I suppose he means the bullet gets started, then the pressure stalls, then starts again, thus hitting a stuck bullet from the stall.

  • dresign

    I have a bullet that I like know the BC, 2R design, aol 1.06, Dia 457 cal, the 45 apc swagged to 457 cal with 240 grs Lyman 429-2R mould wieght 325 grs