(Another?) New AR15 Round – The .375 Reaper

UPDATE 2016 : A number of people claiming to be customers of Whiskey 3 Precision Systems (which may be going by the name Terminal Ballistics Group today) have complained to TFB regarding their orders not being fulfilled. We recommend caution when placing orders. 

I know there really is enough rounds for the AR platform that it will give you a headache just from trying to keep up.  Now there is yet another round in R&D out there.  Although the .375 Reaper is still in its infancy, there are various AR forums that are calling it the next .300BLK round and a contender to the .458 SOCOM.  While I am not sure I agree with that, ballistics have always been fascinating to me, and building rounds is how we innovate and down the road save lives with better rounds for the police and military.

The case for the .375 Reaper is made from .308 brass that is cut down in length and then necked down to accept a .375 bullet.  The round will also fit standard AR15 magazines, but your 30rd magazine becomes a 15rd magazine with the .375 Reaper.  All that the end user would need to replace would be the bolt and barrel to be able to accept the new round.  So just like being able to switch from 5.56 NATO to .300BLK just by changing the upper, this round would offer the same modular ability to the end user.

.375 Reaper and .300BLK

.375 Reaper (L) and .300BLK (R)

Because the round is still in the R&D phase, there are no official ballistics yet (that I was able to find) but I can imagine that the round, much like the .300BLK will be a big, slower moving round that will hit very hard and be dedicated to CQB shooting and inside of 300m. Reading through comments that W3 Precision has made, it looks like it will probably end up being a 200gr Spitzer bullet with a MV around 2300-2400fps, but of course that is (as always) subject to change.

Using the Applied Ballistics online calulator, I was able to build a mock round with a 200gr Spitzer bullet to show some of the possible ballistics.  Here are the ballistics based on some rough numbers.  The round begins to drop off at 300yds with a 22in drop, but at 400yds you end up with a bullet drop of 4 feet.  Inside of 100yds the energy is right up there with a .308WIN and well over that of the .300BLK 220gr bullet (498ft-lbs).  We will have to wait for official ballistics to come out, but early number look promising.



I will admit, my first reaction is that this is yet another round for the AR platform, but one that could be one to watch.  The numbers are definitely interesting, and lend credence to the round being viable for various uses. Many are watching the round as a contender against the .458 SOCOM, the .375 Reaper being a cheaper alternative using more readily available brass instead of proprietary brass.  If you are interested in keeping an eye on the progress, Whiskey 3 Precision Systems is posting updates on their Facebook page http://www.facebook.com/W3PrecisionSystems and has some other links listed to follow the progress.


.375 Rounds in a standard AR magazine.


Thanks JBR for the tip!


  • So basically, it is a .375 Whisper loaded short enough for an AR-15?.

  • BoHeck

    Looks interesting for sure

  • Zachary marrs

    The next .300 blackout?
    Would the .300 blackout be considered a failure then? Kinda soon to bring in its replacement dontcha think

    • Risky

      I don’t think the author meant ‘next’ as a replacement but as in the next wildcat for AR15’s to really take off like .300 BLK has.

      • ColaBox

        I wouldn’t say .300BLK ever really “took off”, its still obscure as hell and $25 for a box of 20. I wanted to barrel swap from 5.56 but even the .300 guys out there seem to say its not worth it. Less plinking, more money.

        • Ben M

          300 blk has most certainly taken off… just about every major ar manufacturer has factory 300 guns, and most new models are released with a 300 variant. Ammo is another story, but its a total non-issue if you reload. Besides, if you are thinking about this as which one is cheaper to plink with, why even the 5.56 instead of .22lr?

          Personally, I think the 300 blk is the bees-knees, but you have to use it for its intended purpose. Do you own a suppressor? Do you plan on buying a surppressor? Do you own a sbr’d lower/plan on owning one? If the answer to any of those questions is “no,” then you probably shouldn’t be buying a 300 to begin with. Sure its the “hot” and “cool” caliber of the moment, but the 6.5 and 6.8 will arguably give you better performance from a 16″ gun. The point of this caliber is to give you the versatility of a 30 cal round that can be fired both super sonic and subsonic, with great performance metrics for each intended purpose (ft/lbs for supers, dbs for subs, even with (especially with) shorter barrels).

          To each their own though. I would never consider purchasing a 16″ 300 blk upper/barrel, and I wouldn’t consider the 300 at all without owning a suppressor or planning to own one (I am assuming you weren’t swapping the barrel of an sbr, if that assumption is incorrect please ignore half of the above)

          • ColaBox

            We seem to have a different definition of “taken off”‘. To me as a non-reloading consumer, it means I can find it at my local sporting goods store or rifle range, however with 6.5, 6.8, and .300BLK, you cant. Sure a lot of manufacturers now have AR’s in .300BLK, but can anyone who bought them afford to feed it? If I have to wait 2 weeks to go shooting because its only available online, then there is a problem.
            Every caliber has its limitations, but 7.62×39 stopping power fused with near 5.56 accuracy with only a barrel change is hard to not get excited about. 16inch barrel or not, I just wont grab Whisper. Now once NATO adopts it, and we see it filling the shelves, im all for it.

          • Ben M

            If you’re waiting for NATO to adopt a caliber before you purchase a gun for it, you may be sticking to 5.56×45, 7.62×51, and 9mm for a long time…

            The last assault rifle caliber to be approved as a NATO round was 5.56 in 1980 (which for the record, was 17 years after the U.S. made the M16 its primary infantry weapon, and at a point when many other NATO countries already relied on the round). Adding a NATO caliber is not something they take lightly. The last one they attempted to add was 5.7×28 for a universal PDW round, and even that didn’t get done because they couldn’t come to consensus on this round vs the 4.6×30.

            Consumer demand will get this round onto more shelves, not military proliferation. That said, maybe you are not looking hard enough… I have seen this round commercially available at Wal-Mart, Cabela’s, as well as other big-box retailers and boutique gun shops alike. I will agree though, the factory ammo certainly is not cheap.

          • Sulaco

            Saw a lot of .300blk at the big WAC show in Puyallup WA this afternoon. But holly moelly I didn’t want to take out a second mortgage! WELL over a buck a round.

          • iksnilol

            Just use 7.62x39mm and handload if you need subsonic loads.

          • Sulaco

            I’m going to update that cost slightly. Went back to the show this Sunday and noted boxes of factory .300blk, 250 rounds FMJ for $199.00, so better? 7.62×39 dropping to around $100 +/- for 500 rounds…stockup time.

          • As 300blk goes, I am finding that ~$1 a round is not all that unreasonable, but a little on the high side. But for local NW prices, it’s something I would consider buying.

          • You’re in my home state then, where .300blk seems to be a little harder to find, and more expensive when you do. Been to a few WAC shows, and .300blk is always astronomical in price at them.

            I actually never buy ammo at WAC shows anymore, unless its from a reputable ammo company… Too many people out there reloading and calling them factory new. I have seen more than a few guns destroyed by someone’s “factory new” reloads from a WAC show.

          • Sulaco

            Sam I was looking at the ammo dealers, two big ones at the show. I didn’t see who the maker was but it was in the same lane as the 5.56 and AK ammo. I just don’t see the need but hey, that’s America…

        • ArmySniper

          You obviously don’t know how to find cheaper ammo online, or don’t reload. I can even find 300BLK for $18/20rds locally.

    • This was also my sentiment… .300BLK is just getting going, why try to replace it so soon?

      • Zachary marrs

        So you have no data for it? It SOUNDS like a good bear round, but I live in texas, so what do I know

        • I have no official data on the round. Although talking with them about the round, the number are solidly in the ball park.

          It would be a good bear, but would depend on your hunting. When I bear hunt my shots can be 300yds+ in clearings. So I use a round with less drop to it. For the guys that hunt in the woods, generally their shots are inside of 100yds, so it would be a very viable round.

          • John Bear Ross

            Feral Pigs. This thing looks like it’s tailor-made for taking bacon.
            That alone should guarantee a lot of orders from Texas. 😉


          • Valintino Pak

            Maybe Missouri too, the Show Me State has been having trouble lately with feral pigs too.

          • John Bear Ross

            I wish we had a pig problem here in Nevada. I loves me some bacon.
            I have kin in Cajun country, though. I know there’s good pig hunting down there.


    • Laserbait

      It’s not a replacement, it’s an alternative. Personally, I like this better than the 300BLK, because you’d never have to worry about chambering the wrong ammo into your gun, and I don’t do subsonic anyway.

  • guest

    Put a heavy bullet in it, and you got yourself the 9×39 alternative.

    • iksnilol

      Why not just use 9×39? 9.3 mm bullets aren’t that rare and 7.62×39 brass is easy to get (even the match stuff).

      • For US customers, it would be easier to do a 0.358″ variant of the 9x39mm given the availability of barrels and projectiles. In fact, it is already being offered as the .358 Gremlin.


        • iksnilol

          I heard about the Gremlin, seems nice.

          Are 9.1mm bullets that common, especially hunting bullets? I mean, only .35 Whelen, .35 Remington and .356 Winchester (IIRC) use 9.1mm. That I know of that is.

          • There are also the .358 Winchester (the rimless father of the .356 Win) and .350 Remington Magnum. They may not be as popular as the thirty caliber rounds, but the .35 Whelen and .35 Remington have cult followings.

          • G

            358 Norma Magnum and 358 Shooting Times Alaskan are two hard hitting .358″ cartridges

      • Eddy

        7.62×39 brass won’t fit nicely into a standard AR magazine. 9.3mm bullet vs. .375, take your pick. Maybe you could create yet another AR wildcat, the 9.3mm iksnilol! 🙂

        • iksnilol

          There are 7.62×39 AR mags, granted those are a bit rare and expensive.

          Main thing is I ain’t in the AR club so I don’t consider AR compatibility to be that important. Granted, if I use 5.56 I like having Stanag mags.

          I would never make an AR wildcat, just because of too many limitations. If I were to make a wildcat it would be 14.5x114mm brass necked down to .50 caliber. Load that with the heaviest (high BC) bullet and push it to about 1 km/s (3300 FPS) at the muzzle. Would be (relatively) mild pressure and high velocity.

          • Eddy

            Rare and expensive magazines are a problem from the marketing perspective. The makers of the .375 Reaper probably want their new round to be a commercial success, so having a round compatible with common Stanag mags may help with their adoption by the popular AR crowd.

            So when is the .50 iksnilol being released? 🙂

          • iksnilol

            Not for a while. Need drivers license first, need to be old enoygh for gun license. Then I need to get 14.5x114mm brass (anyone have a KPV MG?).

            Then I either need to make it on a hunting license or get involved in some long range club.

  • gunslinger

    wait, is this for an ar10 or ar15?

    • sianmink

      AR15 with a bolt and barrel swap.

  • Come to think of it, a 0.411″ variant might be feasible. You could run projectiles ranging from those designed for the .41 Magnum up to the .405 Winchester and .400 Jeffery Nitro Express.

    • Anonymoose

      .411 Hawk and .400 Whelen already exist for the .30-06.

      • True, and SSK also offers a .416 Whisper based off of the Remington Bench Rest case. While meant for .308 length actions, I don’t know if J.D. Jones has ever attempted an AR-10 conversion with the .416. I proposed the .411 Bench Rest wildcat: 1) to have a ready supply of short ogive projectiles to fit in an AR-15 magazine; and 2) to avoid stepping on SSK’s shoes.

      • Andrew R

        Cut down .308 brass for AR-15 mags, size it for .411, call it the .411 Shrike.

  • Renegade

    I’m waiting for people to chamber ARs in old cartridges…

    Now, From Tactical Manufacturer X, comes the upper we’ve all been waiting for… a round made famous by the lawmen and gangsters of yesteryear… .351SL!

    • wetcorps

      You know what would be cool? More guns chambered in 7.92×33.

  • seriously?

    Why not just chop the .308 brass to fit your OAL, and then use a damn .308 bullet?

    components are scarce enough as it is, no need to use something noone will be able to find.

    • Steve Truffer

      Congrats, you just figured out Remington’s entire design work for the .30 Remington AR cartridge.

    • Mark N.

      Being a novice on ARs, if you are going to use a .308 case and bullet, why chop it all and just use an AR 10? You’ve already given up your capacity, and the shorter length will same negligible weight, I would think, meaning all you are making is a neutered .308, right?

      • Steve Truffer

        $8 mags vs $23, and most AR15 parts are a good deal cheaper than AR10 counterparts. Plus the AR15 has at least an order of magnitude more parts available. That said, I’d still take a Vepr over an equally priced AR.

        • HKGuns

          Ha! I’d rather spend the extra money on magazines. This is getting stupid.

      • adfds

        It’s not a neutered 308. Neutered 308 is 300blk, which is more like morbidly obese 556 anyway.

        It’s 358. It’s specifically fat, high BC bullets, that can work far better than 300blk. Don’t like it, don’t use it. It’s just as easy as 300blk to make, and most people shooting 300blk are reloading anyway.

    • Laserbait

      That’s been done already. It’s called the 308×1.5″ Barnes.

      There’s nothing scarce about .375″ bullets. They’re easy to get, and 308 brass is plentiful.

    • sdfafsd

      Why? Because practically speaking, people already do that with 300blk, only with 556 brass, and with full 30 round capacity rather than 15.

  • Lance

    I prefer to stay with 5.56mm for a AR. If you want a bigger bang get a M-1A or AR-10.

    • Laserbait

      I’d rather have the AR15 with some of these wildcats. Much lighter, and more cost effective for the platform.

  • UnrepentantLib

    Someday firearms historians are going to have good laugh at the way we tied ourselves into knots trying to design cartridges to fit within the restraints of the AR15 magazine. Not that it isn’t good, harmless fun.

    • People have been doing it for over a century with the Mauser 98. Why should military surplus bolt actions have all of the fun?

      • hod0r

        Difference is the Mauser has ample length do accept cartridges a good bit longer than the original 8×57 (7×64 e.g.), whereas the AR-15 magazine was made for 55 gr 5.56×45 and nothing bigger. Even just a heavier 5.56 has to be shoehorned into mag length by seating the bullet deep into the case, without the ability to accept long ogives.

        • Wildcatting is an obsession. Give a wildcatter an action, and he’ll start to imagine everything that he could shoehorn into it.

    • n0truscotsman

      or why we went out of our way to squeeze blood out of a turnip when it comes to making cartridges better for specific roles…

      our grandchildren will have huge laughs as they grasp their 12 kilowatt lorcin 25-shaped phasers capable of blowing 1’x1′ holes in RHA.

      • UnrepentantLib

        I’m reminded of the way the Brits opted in the 1880’s to go with a rimmed cartridge so they could recycle their single shot Martini-Henrys, then spent the next 60+ years having to make the .303 work in repeating and self-loading weapons. It comes down to does it make more sense for the platform to dictate the cartridge or the cartridge to dictate the platform?

        • El Duderino

          Sort of like the current action in replacing the 12g. Rimmed and plasticy is no way to go through rapid fire, son.

    • Jim USMC

      No they won’t.

      There’s nothing wrong with trying out a new caliber, and nothing wrong with the AR15 platform either. You probably don’t understand the reasoning for using the AR as a jumping point, but if you must know, its because it is currently used by the US military and many other countries and armies. A good alternative is to use the 7.62NATO AR10

      So basically you want to create a new round that will fit in a rifle that is widely used by the most militaries or civilians. Not that hard to comprehend, is it?

  • John

    Sam, your estimates say that it’ll be roughly similar to the [very old] 9mm Mauser…..

    • Roughly, yes… Although I have no idea what the actual number will be… I have a sneaking suspicion that they will be close to what I have approximated here, based on some information I have put together by going over the companies facebook page.

      • John Allen Culpepper

        Got US Army witnessed testing of very light powder charged 235 grain Barnes TSX projos this morning at Fort Benning. 
        21 grains of h110 
        2000 fps

        Keep in mind that this case holds way more than that in capacity and is considered a very low charged case at 21 grains of h110. 

        Other witnessed tests are coming with the normal loads and 1680 looks to be the real winner in powder so far. 2400 fps with a 200 grain projo is a cake walk and will be verified and posted as soon as the boys in Green get jiggy with it again in the next few days.

      • John Allen Culpepper

        ***New update from Fort Benning***

        2,365 fps out of 26 grains of h110 pushing the Barnes 235 grain TSX

        Witnessed and confirmed by US Army personnel. …..

        Also intial reports are that the 250 grain Sierra game king will be pushing this at 2200 fps with a whopping 2900 foot pounds of energy! ! Good enough for any large game on the North American Continent!!!

  • Mack

    Personally i like it, i wish more ar-15 wildcats used readily available .308 case cut down!

    • Practically speaking, wildcats for the AR-15 are limited by the size of the bolt. Once you’ve opened the bolt face for a .308 Win-sized casehead (or larger), you’ve dramatically weakened the bolt and risk cracking/shearing the lugs. A high pressure wildcat would require a proprietary bolt and barrel extension along the lines of Remington’s .30 RAR upper and Olympic Arms WSSM and .22-250 uppers.

      • Mack

        That makes a lot of sense, but would a proprietary barrel extension require a redesigned upper you think? because if your doing a wildcat, odds are you are already replacing bolt, so if it was proprietary bolt with proprietary extension that wouldn’t be the end of the world, but if it became so proprietary that you had to switch uppers and regular handgaurds, that would be way farther then i would be willing to go!

    • John Allen Culpepper
  • John Bear Ross

    The round has promise.
    Happy to help.

  • Mike

    .375 Winchester redux in an AR-15 cartridge envelope.

    • Now that you mention it, you could make a rimless .375 SuperMag by necking out 6.8mm SPC brass. Wildcatting is a sickness, I tell you!

      • Alberto Paulson

        I made some crazy 9×25 Dillon brass from SSA 6.8 SPC brass. 180gr xtp @ the speed of awesome in my throated lone wolf G20 barrel. Gotta look on my old computer to find the vids.

  • adfsdadfdsf

    It’s not even an attack on 300blk, you nerds, so stop panicking just because you bought your cheezy 11 knight’s guns. It’s just an alternative to 300blk, that goes balls out instead of trying to stay a rifle round. It’s as close to an American 9×39 as we’re going to get right now.

  • Alberto Paulson

    “375 is JD Jones favorite whisper.” Can’t remember where I read that lol. I previously worked at a shop and made a, .375 HUSH (PT&G reamer) SR-25 pattern rifle with a 350gr SMK, before that bullet was even a Sierra item. I think this .375 in the article is a happy pipe dream for feasibility. The .338 SPECTRE will eat this for lunch in an Ar-15 platform.
    But none the less .308 brass can make some great wildcats. I also wish the .30 rem AR caught on for us tinkerers just for the brass alone. It is nice to see enthusiasts still making some fun stuff, because that’s what its all about. So A+ for effort, now make the biatch feed and shoot . :] Big up to Dave Kiff @ PTG he makes the world rotate for tinkerers.

  • pwrserge

    Meh…. The magazine capacity reduction is a huge deal. You’re down to little more than .50 Beowulf capacity in a much less capable short range round. The beauty of .300 AAC is that you’re still packing 30 rounds in a 30 round magazine.

    This may be a toy for bench shooters and hunters, but I don’t see it having the same prevalence as more established rounds.

    • John Allen Culpepper

      With a round this big who needs 30 rounds?? 300 aac is great for what it is but this far exceeds it in many ways!

      • pwrserge

        “I wish my magazine held less ammo.” said nobody ever.

        In any case, if I’m going to swap uppers and get less capacity, I’ll skip the middle man and go to 50 Beowulf.

        • John Allen Culpepper

          And you also sacrifice accuracy. ….50 be owl is like slinging a shotgun slug …..no distance like talking about it and accuracy suffers ggreatly. ….same goes for .458 socom

          • pwrserge

            Not as much as you’d think. Besides, within 300 yards 2 moa is six inches. More than enough precision for that projectile.

          • John Allen Culpepper

            Beings I created the .375 Reaper ® I think I sorta know what I’m talking about when it comes to Precision ….that’s my business is creating the most accurate projectiles on the planet. Just saying…..it’s all in the end user as well.

          • pwrserge

            Oh, I’m not arguing that the .375 is more accurate. I’m just pointing out that within 300 yards .458 and 50 is more than sufficiently accurate and will hit MUCH harder.

            It’s cool to chat with the creator, I just think that giving up 50% of your magazine capacity vs 66% is not much of an advantage vs a round that hits a lot harder and is still accurate enough for what I see it being used for.

            From what I read, .375 is not designed as a 400 yard + round and when you stay within that 300 yard envelope the difference between 2 MOA and 1 or even 0.5 MOA does not (to me at least) make much of a practical difference.

            As for most tactical applications, 300 AAC has the major advantage of double the magazine capacity. (Leaving aside the games you can play with SBRs and suppressors.) It might not hit quite as hard, but it hits twice as often.

            I would be jumping for joy if you used something closer to a 6.5 Grendel case and gave me an awesome short to medium range round that hits almost as had as .458 with negligible drop in magazine capacity… Sadly, that is not what you have here.

            But then again, I’m a tactical applications guy. You will probably get a much different response from guys looking to get the accuracy you designed. To me, however, it’s all about either punch or magazine capacity. I am willing to go to opposite ends of the spectrum on that, but the middle ground seems like the worst of both worlds.

          • John Allen Culpepper

            Well between the accuracy. …ease of versatility in the platform….being able to convert your own brass on a budget….and be a more accurate and heavier hitter than 300 aac “due to the complaints we get from guys running 300 blackout” we think we have reached a compromise. When a guy like Dave Kiff gets excited about a round when in his last 30 yrs he’s seen it all we take that as a compliment.
            Thanks for the input none the less. ….we are working on new things everyday.

          • pwrserge

            I think I see your point. I don’t even think about the reloading angle and most of my “social work” involved 5.56×45 NATO. Like I said, my point of view is limited and a bit biased.

          • MarylandShooter

            1.66 MOA at 100 yards with an Aimpoint, so I’d hope to be better scoped, but with a slug that hits that hard, do I need any better?

  • Secundius

    I think their trying to make the M4 Carbine/Rifle Rig and/or Frame, a Mult-Purpose design chassis for swap-outs, for multiple caliber receivers or simply put a “Jack-of-All-Trades” or “One-Size-Fits-All” weapon system. I don’t know whether that’s a Good thing, or a Bad thing. Theoretically there’s a limit, on how many things you can use the frame for.

    • pwrserge

      Well, the M4 platform is versatile enough that with upper receiver swaps you could conceivably cover a multitude of mission profiles. However, the stupidity comes in trying to engineer specialty ammunition that does things already available in other loads with minor tradeoffs.

      This is a classic example of what I refer to as a snowflake round.

      300 AAC does the short range envelope a lot better without sacrificing magazine capacity. Sure it does not really pack the punch, but the disadvantage is not huge when you consider the fact that every magazine carries twice as many rounds.

      .458 SOCOM or 50 Beowulf do the sledgehammer thing much better and don’t sacrifice THAT much magazine capacity for DRASTIC improvements in stopping power.

      As always, 5.56×45 remains a good “jack of all trades” compromise.

      This round seems to be trying really hard to split the difference between 300 AAC and true big bore calibers without really maintaining the advantages of either and not really brining anything drastically new to the table. (Like the 6.5 Grendel)

      • John Allen Culpepper

        Not sure the source on magazines that you have on .458 socom but here is what you get with .458 socom in standard AR 15 mags as a reality. ..
        10 rounds of .223 – 3 rounds of .458 SOCOM
        20 rounds of .223 – 7 rounds of .458 SOCOM
        30 rounds of .223 – 10 rounds of .458 SOCOM
        40 rounds of .223 – 13 rounds of .458 SOCOM

        • pwrserge

          Yup. That’s what I was working off. I personally like 50 Beowulf over .458 SOCOM, but that’s just me.

  • smartacus

    hmmm 375? Now you got me following a train of thought…

    -What would a .375 Magnum handgun be like? How hard is it to cut a .375 Winchester case down to 1.28″ and use the same 200-220gr. FP’s?

    **uh oh! Now you got me thinking what if they made .375SIG and 9.5×25 Dillon!!

    • Cut-down wildcats of the .375 Winchester case been done already. Look up the .375 DAK and the longer .375 SuperMag. Unfortunately, either approach results in tapered case. The case is fat enough to be necked out for 0.401″ projectiles.

      The stillborn 9.65mm FN and 9.8mm Colt semi-auto pistol cartridges from the early 20th Century were essentially based upon a rimless version of the .41 Long Colt case. However, a .375 round based on the 41 Long Colt case would still be slightly tapered.

      For a straight-wall .375 handgun cartridge, I suspect that you’d need a case-head between 0.395″ and 0.400″. If such a case existed, it would fairly easy to convert existing 9x19mm or .38 Super pistols for a rimless variant. A rimmed version could be used in conversions of .357 Magnum revolvers with thick walled cylinders. The Ruger GP100 and S&W L-Frame was be easy conversions, and I suspect even the Ruger SP101’s cylinder could be safely bored out for a .375 Magnum.

  • valorius

    I see no point at all to this round.

  • buzzman1

    What barrel length was used in your fcalculations?

  • Lujan

    If this .375 fits in an AR-15, why not neck it down for a .300blk? Side by side it seems a bigger case with a aerodynamical bullet would be interesting.

  • Lawrence C Spies

    I’ll stick with my 6.8

    • MarylandShooter

      And my 458 SOCOM

  • Hyok Kim

    Is this just another gimmick to get the shooters to spend more money?

  • All the Raindrops

    How do you figure getting 2400 fps out of shortened (to 223 cartridge length) 308 brass with a 200gr bullet, when normal 308 is around 2750fps with a 160gr bullet. You would have to do that entirely with powder and have unsafe operating pressure. I think a projection of 1800-2000fps would be more reasonable.

    • MarylandShooter

      This is why we see no real world data. There is none.

      • John Allen Culpepper

        Please excuse me not being able to find the post for your reply as the email link just directed me back to the article itself for some reason. Thay being said…..if you go to our fb page or you tube you can see it running from the standard AR 15 magazine just fine. Also as a smart business man the reason for the wait on numbers and videos was directed by our Trademark lawyers and legal staff. As common sense as it gets when it comes to protecting my creation. I have had 2 well known companies already try and steal it with no avail.

    • John Allen Culpepper
  • Nick Aviles

    “While I am not sure I agree with that, ballistics have always been fascinating to me, and building rounds is how we innovate and down the road save lives with better rounds for the police and military. ”

    Bullets take lives no save them stupid lol.

    I am not sure I agree with that, ballistics have always been
    fascinating to me, and building rounds is how we innovate and down the
    road save lives with better rounds for the police and military. – See
    more at:
    I am not sure I agree with that, ballistics have always been
    fascinating to me, and building rounds is how we innovate and down the
    road save lives with better rounds for the police and military. – See
    more at:

  • MarylandShooter

    Vaporware with nice charts. Where is real, hard data?

    • John Allen Culpepper
      • MarylandShooter

        Well John it only took two months. Why was he single loading his ammo?

        • John Allen Culpepper

          Do I have to shoot through a chronograph with a magazine in my gun? Just wondering? That’s me in the video …….if you want to see it function and feed you can check that video out on Facebook or on you tube. It’s there. What’s your thoughts on the numbers by the way? Makes you scratch your head doesn’t it? Lol. Trust me ……I did too. My dad always tells me I’m the only guy he knows that can stick his hand in a toilet full of poop and come out with clean hands and a gold ring on each finger. It’s crazy but these numbers you are witnessing are 100% legit.

  • MarylandShooter

    Vaporware with nice charts. Where is the real, hard, actual data?

  • greg

    So why not just go with the 6.5 Grendel? It out performs the 5.56, the 6.8 SPC, the 300 BLK, and the venerable 7.62/308. What possible advantage would this round serve over the 6.5 Grendel?

  • John Allen Culpepper

    Got US Army witnessed testing of very light powder charged 235 grain Barnes TSX projos this morning at Fort Benning. 
    21 grains of h110 
    2000 fps

    Keep in mind that this case holds way more than that in capacity and is considered a very low charged case at 21 grains of h110. 

    Other witnessed tests are coming with the normal loads and 1680 looks to be the real winner in powder so far. 2400 fps with a 200 grain projo is a cake walk and will be verified and posted as soon as the boys in Green get jiggy with it again in the next few days.

  • supergun

    They use the 308 brass necked down. The bullet looks skinnier????

  • John Allen Culpepper

    The Author has updated the article for anyone who wants to see real world numbers.