Holy $%!7 – OATH 12 Gauge TSR Slug

Sometimes there is no replacement for the immediate exclaiming of an expletive. Most of the time I let one fly its due to someone or something’s rampant stupidity, but on the flip side there are things that are so awesome to behold that no other set of vowels and consonants can do it justice.

A rare entry to the latter category is the OATH ammunition TSR (Tango Shotgun Round) slug, which upon expansion clocks in at a whopping 2.6″+! The 12 gauge round follows similar expansion technologies in their Tango series, which we tested just a bit ago (but found the high expansion detrimental to the handgun round). If that applies in the 12 gauge with significantly more energy, it remains to be seen but in some manufacturer gel testing, it went a full 12″.

The all-copper slug is an unusual shape (called wasp-waisted by our sister-site’s Oleg Volk) coming in at an impressive 602 grains (a bit over 1.3 ounces). The projectile is 100% machined with o-rings at the front and rear for keeping the petals in during flight and getting a good boost from the aluminum(!) shell.


Yes… I did say aluminum… The hull is machined from billet and according to OATH, its easier to extract than traditional plasitc hulls. On the practical side, the stronger hull will keep its shape even when loaded into a magazine-fed shotgun. Ovoid hulls deform easily over time (Especially adding in some heat like in a car trunk) which will cause semi-autos to malfunction.

Check out additional details from our sister site, AllOutdoor.com. The TSR is also available for pre-order. Retail clocks in at $34.95 for 5 rounds, which I consider “not bad” if the performance is there.

Nathan S

One of TFB’s resident Jarheads, Nathan now works within the firearms industry. A consecutive Marine rifle and pistol expert, he enjoys local 3-gun, NFA, gunsmithing, MSR’s, & high-speed gear. Nathan has traveled to over 30 countries working with US DoD & foreign MoDs.

The above post is my opinion and does not reflect the views of any company or organization.


  • Anonymoose

    But how is it for deer?

    • Schadavi

      Would probably kill them.
      Judging from the size of the mushroomed bullet, it destroy at least several pounds of meat and leaving massive bruising but no exit wound – that is, if it doesn’t loose it’s petals.
      If it looses petals, you can probably throw away half the meat…

      • Devil_Doc

        Lol.. Can’t get much deader than dead.

        • Schadavi

          Usually the reason to shoot a deer is not just having a dead deer, but having lots of delicious venison.

          • itsmefool

            Think he meant zombie deer.

  • USMC03Vet

    That’s more than .50 BMG ammunition.

    What is this for, zombie bears with ebola?

    • HenryV

      You don’t want to know what it is for……………….. 🙂

    • CavScout

      I think mil ball still has a heavier bullet. Either way, I’m sure the ft/lb force isn’t anywhere near there. Apples vs Oranges…

  • The problem with these kinds of rounds is always penetration. When they expand they – by definition – have very poor sectional density. I can calculate the exact expanded SD when I get home, but without very high velocity these sorts of projectiles lack penetration.

    • TheSmellofNapalm

      Just listened to your military caliber configuration podcast, VERY interesting stuff man. Do you know what the closest thing to M855A1 would be for civilians before there’s surplus?

      • ostiariusalpha

        Solid copper hollow points are the most effective barrier penetrating projectiles that have decent terminal performance.

        • TheSmellofNapalm

          So Lehigh Controlled Chaos 115 gr .300 BLK? Most of the CCs are brass, except for that round. Pretty crazy results

          • Maybe I just have an inclination to be boring, but I’d rather choose the Barnes 110gr TSX for .300 Blackout.

          • joedeats

            Problem is over penetration of rifle rounds. I like the 300 black out and the 7.62/39 but faced with someone in my home who might be near a loved one I want the round to stop in their body. I can see the merits these rounds have

      • I like Mk. 318. Barnes bullets are also good.

        • ostiariusalpha

          I’d put a TSX over the Mk318 anytime.

          • Well, I think my attachment to Mk. 318 comes from when they were $0.45/round.

            Both are very good projectiles.

      • john huscio


        • TheSmellofNapalm

          I love that round but I think those two have very dissimilar ballistics

    • Alright, SD of the expanded Oath 12 gauge slug is 0.039 gn/in^2. That is less than half the SD of a 32gr .22 LR bullet, or about the same as a single BB shot pellet.

      For the record, this is how I measured the frontal area of the projectile:


      • Rebecca Lopez

        You have to see the video that they did with the FBI jelly. It’s incredible. I think if I recall correctly it was like 7-9 inches penetration. I’m no expert but I think that is enough to get something stopped. I think I saw it on their facebook page.

    • ostiariusalpha

      It’s all about engineering when the petals unfold; you want some appreciable penetration before the petals fully expand. It’s stupidly complicated, because if the projectile is going over a certain speed then it will expand too soon, but if it’s going too slow then it might not expand much, if at all. And shotgun slugs have terrible ballistic coefficients, so hitting something at 10 yards is almost completely different from hitting at 150 yards, as far as terminal performance goes.

      • The projectile is very likely to be velocity sensitive; if you fling it too fast, those petals will bend backwards and/or break off, which is bad.

        To compare, the Oath Ammunition 12 gauge slug when expanded has about half to 60% as much sectional density as a typical handgun JHP when expanded. So we can expect its penetrate to be accordingly reduced over a similar velocity range.

        It seems like every year or so, some company releases a shotgun slug like this. It’s a little strange, because shotgun slugs already have excellent expansion, so maximizing that at the major expense of penetration seems pretty misguided.

        • Devil_Doc

          Why would it be bad if those petals fragmented off? Each one has to be fairly heavy (compared to say, 5.56) for a fragment, and even if all broke off, you’d still have the base penetrating while the petals shredded tissue. Seems pretty effective as a man stopper..

          • Let me put it this way: Would you rather spend $7 a round for this stuff, or $1.50 a round for 12 pellet 00 buck?

            The whole gimmick here is the ridiculous expansion. If I wanted to throw a few hundred grains of fragmented mass at the target, I could use much more common and available buckshot instead… And it would probably penetrate more deeply into the target, too!

          • Devil_Doc

            Yeah, I guess I can see that. I don’t know that 00 buck really dumps that much energy into tissue though. I mean, its real wounding potential is shredding tissue and multiple small projectiles=greater chance of hitting something important. This round stays intact until it hits tissue, begins to expand, and dumps all that energy into tissue. Huge temporary wound cavity, and assuming that it doesn’t fragment, 2.5 inch permanent hole 12 inches deep. That’s pretty significant. I would think that if you’re using this, then the cost doesn’t exactly matter. I guess it all comes down to the math whether or not 1 gigantic projectile massively deforming in tissue is preferable to multiple non deforming projectiles boring neat holes through you. I do know I wouldn’t want to be shot with either.

          • Steve R

            Buckshot (Lead, non plated) deforms into miniature saucer shapes, same as the old percussion pistol balls did. For me, slugs are for greater penetration and range, and while this slug could be amazing, it accomplishes neither task as well as my hard cast 66 caliber roundball sabot handloads @ 30-40 cents each, depending on component costs

          • Andrew Foss

            I think the idea here is to minimize overpenetration by dumping energy into your target. 00 buck tends to sail right on through your average freelance Marxist, through a wall, down the block and through another wall into someone you don’t want to see take a trip to a hospital, (If you live in a city or apartment) because projectiles that exit the target are projectiles that are (effectively) wasting energy.

            Cops have to shoot at all kinds of perps at weird angles and drip with qualified immunity, thus the FBI 12-18″ penetration depth rule. (Sorry we shot you through this member of the criminal classes, bystander…)

            Were I a criminal, 8″ would be enough to go through me (and my upper arm) about halfway in the lateral orientation. 6″ is enough to go right on through me front-to-back. I’m 5’9″, 150lb. 12″ worth of penetration on an 8″ deep target and a severely mushroomed projectile tends to peter out before too long. 14″ worth of penetration on an 8″ deep target and still a 0.33″ sphere is enough to kill someone else.

            Now, all that said, I wouldn’t buy it right off the bat to replace the slugs I use in my shotgun for social purposes: I want to see unbiased third party tests in gel first. And even then, that might not be enough to convince me.

          • Paladin

            Penetration in gel is not the same as penetration in real world use. The notion that 12″ of gel penetration implies that the projectile would pass through a human target is common but incorrect. Gel is a reasonable simulacrum of muscle tissue, but people are made of more things than muscle tissue. You can’t really add things like bone to gel tests because it would make it very difficult to get consistent results. Rather than presuming that the wound tract in gel would be replicated as is in a human target, it’s more useful to think in terms that a round that produces X effect in gel will have Y effect on a living target, specifically, that a round with 12-18″ of penetration in gel will penetrate the human body sufficiently to reach vital organs, without significant risk of passing all the way through.

          • Core

            Living hogs would be way more accurate.

          • TraumaDoc

            I’ve taken care of countless GSWs over the past 15 years as a trauma anesthesiologist in a violent Northeastern inner city. Almost every common caliber included. The few victims I’ve see hit with 00 buck…well let’s just say “it’s VERY effective”.

          • Rebecca Lopez

            I saw a third party test in FBI approved gel is incredible..

          • john huscio

            Neither, gimmie some brennekes or ddupleks

          • AK™

            Alaska State Troopers use Brenneke slugs in their shotguns for bears. Which is why I had a few boxes for my 870.

          • Core

            This round would maim you severely if you didn’t bleed to death. You should shoot one into water, and one into clay. Pour water into the clay to measure tissue displacement. Measure displaced water volume and get a non cad result.

          • Rebecca Lopez

            You have a good point but if 12 pellets are flying in my house in the middle of the night? I feel better hitting an intended target than 12 pellets flying in many directions. That’s my opinion.

          • FightFireJay

            Because if they they break off, they arent likely to penetrate deep enough to affect the vitals.

          • Devil_Doc

            It wouldn’t expand until inside the body, so the fragments would already be in vital organs…

          • Tom Currie

            Man stopper yes — but for a 12ga shotgun I can load any number of 100% man stopper rounds that cost a heck of a lot less than $7 each. These MIGHT have some application for a magazine fed (not tube fed) shotgun where there is some need to keep the magazine loaded for long periods of time, under less than ideal conditions. But honestly, the real market for these rounds is people who have far more money than knowledge and who want the bragging rights of having the most expensive load at the range.

          • Anomanom

            DDupleks Dupo 28 slugs get the same principle, albeit with less extreme expansion, for a lot less money.

  • Evan

    “Sometimes there is no replacement for the immediate exclaiming of an expletive”

    Then let us use bad words in the comments.

  • TechnoTriticale

    What keeps the petal end pointing forward in flight?

    This projectile doesn’t even have angled flutes to [hopefully] spin it.

    • marathag

      Center of Gravity ahead of aerodynamic Center of Pressure, an the tail just enough to reduce wobble

  • Kyle

    I bet that thing makes for a real messy gut shot. I’ll probably stick with regular old lead slugs though.

  • Edeco

    Aw, man, why you got to be stealing childrens’ training-verniers out of grade-school science classrooms 😛

  • Imagining the look on the face of the first coroner to pull this out of someone. :-O

    • Nathan Alred

      I was on the receiving end of one of those WTF! phone calls from our medical examiner when we first started using the Billings Precision Choke tactical buckshot – where the shot string was glued down in the flight control wad. Single entrance wound, but 8 OO pellets plus some plastic bits inside the chest cavity.

      • Reef Blastbody

        Only found a webpage for Brenzovich Firearms advertising the Billings buckshot. Will only sell to LE. Maybe try some type of weak glue on regular buckshot to see if you can replicate this for mere mortals so we can have a more effective defensive round too.

      • Giolli Joker

        I’d say somebody else was at the receiving end…

  • Giolli Joker

    Apparently they addressed the weight distribution issue compared to the prototypes we saw in the article back in January.
    These appear to be nose heavy and the dumbbell shape should help with stabilization.
    Pretty much useless but cool looking nonetheless.
    Can the aluminum shells be reloaded?

  • uisconfruzed

    No vid???
    I want to see it hit the gel in HD slo-mo

  • rangerchuck

    What is needed is an old fashion boar hunt with the wonder sluggy and if the hunter prevails, promising. If the boar prevails, no refund on the purchase

  • mike

    Does the shell really need to be billet. They couldnt do it with spun aluminum or something cheaper. Sounds like they just did it to make it sound fancy and worth 7 dollars a shot. I guess the economy must be doing wonderful after all if they really think people have this kind of money to waste.

    • Giolli Joker

      Probably they have CNC milling machines but no other capability of obtaining the shells by plastic deformation. Knowing that their volumes will be quite limited they go with machining, using their limitation as a sell point.

  • Dragonheart

    Seems like this is a solution looking for a problem. Has there been a lot of reports of those getting up and walking away or continuing agression after getting hit with a load of 00 buckshot?

    • Core

      No but most buckshot patterns unpredictably, that’s probably the intent to keep it tighter. And you could just use a expoxy and experiment until you get the right results.

  • Mister Thomas

    I’d like to see the damage cause by a full weight rifled slug plowing it’s way into a block of ballistic gelatin …. vs this copper flower that is lighter and will lose more energy on impact with a similar block.

    I wouldn’t want to get hit with either – and this _is_ most likely a good product – but I want to see the differences between the two.

  • randomswede

    “The hull is machined from billet”
    Wow, that’s “fancy”; but at $7 a round I guess there’s some “wiggle room”.

  • jcitizen

    Machined from billet? Maybe in the 1st step, to build the base plug. It is extremely hard to keep thin aluminum from kinking on a machining center, for something like that; it would not be much to simply pressure form in the final steps. It makes sense, really, as pressure dies are pain to develop, and maintain, for a full form process. Perhaps they are using a roller die and post in the machining center for the final steps – as soft as aluminum is, that could be possible.

  • RickOAA .

    These to complement your Radically Invasive Projectiles in your extendo pistol clip.

  • rocketman

    I would like to see the look on the cororner’s face when he gets a body that has been shot with one of these slugs in the chest!

  • Mike Lashewitz

    Need a video with Ballistic Jel.

  • anonymouse

    What are you shooting that is still standing after being shot with a normal shotgun slug?!