SHOT Show: Seismic Ammo’s Extremely Heavy Projectiles in 9mm, .45 ACP, and 12 Gauge

At SHOT Show’s Range Day, Seismic Ammo unveiled their +M (extra mass) heavy ammo and let us shoot some. How heavy is heavy? How about 185 grain 9mm, 325 grain .45 ACP, and 2.5 ounce 12 gauge slugs . . .

Now, you would normally expect much more pronounced recoil from such a heavy-for-the-caliber projectile, but that wasn’t the case with the Seismic Ammo QuakeMaker. At least not in 185 grain 9mm flavor.

I shot a few rounds of standard pressure 115 grain self-defense hollow point ammo followed by a few rounds of QuakeMaker through an HK USP, and couldn’t really feel a difference. I then did the same thing with a CZ Scorpion EVO pistol, and the direct blowback action accentuated the recoil impulse and the QuakeMaker was unquestionably softer shooting. Not much, but it was there. And the opposite of what I expected.

I know what you’re thinking, and the answer is “no.” These aren’t compressed tungsten or anything exotic; they’re just lead and they’re just large bullets.

The real trick here isn’t the bullet, but the powder. Seismic Ammo has spent most of their development time and effort getting the correct powder blend that propels that large projectile to the desired speeds despite the small amount of space remaining in the case for the powder itself.

For the 9mm — perhaps all calibers, but when I spoke with them we were talking 9mm — it’s a slow-burning powder that’s only just fast enough to get the job done in a pistol barrel thanks to that heavy, slow projectile.

This slow-burning powder is also why the recoil impulse is gentle; more of a long push than a short snap thanks to a wider pressure curve with less of a spike.

At a muzzle velocity of 950 feet per second, QuakeMaker’s expansion is impressive.

Seismic Ammo’s ammo is packaged in 20-round boxes with a bonus round free and is loaded in Shell Shock’s very nice, 2-piece cases. Cost is about $1.38 per round for the 9mm.

As for 2.5 ounce shotgun slugs and 325 grain .45 ACP, they aren’t quite ready for prime time. But they’re coming soon.

And I’m certainly curious to shoot them!

And my sincere apologies for blowing out your speakers with that video. Please email Chris with your complaints.


  1. avatar Blkojo says:

    Boom shak a laka!

  2. avatar Cucamonga Jeff says:

    A 9mm that now has performance of a .45ACP. We are living in the golden age…

    1. avatar uncommon_sense says:


      I wouldn’t quite go that far.

      Nevertheless, a .355 inch diameter bullet that weighs 185 grains and exits the barrel at 950 fps is outstanding coming out of a 9x19mm Parabellum cartridge.

      1. avatar tdiinva says:

        It comes out to 370 ft/lbs at the muzzle compared to 408 ft/lbs for a standard pressure HST 45 Auto from a 5″ barrel.

      2. avatar Art out West says:

        It sounds like something that might be interesting out of a 16″ rifle barrel. I’d bet these rounds would be extremely quiet. Even the 147 grain rounds are pretty quiet out of a rifle. Might be good for some varmit business.

        1. avatar Tom in Oregon says:

          Agreed. Especially out of a suppressed carbine!

    2. avatar Ozzallos says:

      I almost label that sarcasm, but you never know. Ye ole “modern bullet technology” and all that. But, hey, if a 9mm is now a .45, the .45 version must .50bmg. It’s true.

  3. avatar RetroG says:

    Do they stabilize in standard twist barrels?

    1. avatar Cucamonga Jeff says:

      At bad guy distance it doesn’t really matter, but I would be interested to see.

      1. avatar Anymouse says:

        At baffle distances, it does matter. Aguila .22 SSS is explicitly banned in my Element 2 because it won’t stabilize in a standard twist barrel and will strike the baffles. Without a suppressor, it can still affect the hollow point performance. JHP’s don’t expand much when they hit base first.

      2. avatar CraigC says:

        It absolutely matters. The bullet has to track straight and expand in a controlled manner if it’s to be effective.

    2. avatar uncommon_sense says:


      Oh, that is an outstanding question. It is also an extremely important question.

  4. avatar LarryinTX says:

    did I miss something? Dafook is 2-piece cases, and why?

    1. avatar Geoff "Bring the EDIT button back, will ya, TTAG?" PR says:

      2-piece cases are a thing, just not very common.

      TTAG a few years back teased a reloadable 2-piece case, then never followed up on it…

      1. avatar Jeremy S. says:

        That’s what these are. Shell Shock hit the market a couple years ago. They’re great. Lots of advantages to a brass case such as longer reloading life and much higher burst strength, lighter weight, magnetic pickup (use a magnetic broom to sweep them up off the floor and collect them), slightly higher case capacity, etc. Plus you can anodize them in all sorts of purrty colors 🙂

    2. avatar Fcmatt says:

      Old news. Do an article search.

      1. avatar Jhon says:

        Wow. Very helpful. Please comment here more.

    3. avatar BlakeW5 says:

      They’re supposed to be reloadable for WAY longer than standard cases. Not to mention magnetic, so they’re easier to clean up. Can even custom anodize the headstamping.

      They use proprietary reloading dies, but they’re roughly only $100 a set. The dies push the case off the expander/sizer versus pulling it from the rim.

  5. avatar Geoff "Bring the EDIT button back, will ya, TTAG?" PR says:

    Planning on .38 – .357 in the future?

    Those would be *nasty* in a 9mm sub-gun…

    1. avatar Andrew Lias says:

      I’d be VERY curious about power from a longer barrel since they make it sound like you’re going to be optimized for pistol length barrels. A standard 9mm can be at 12-16″ before you start seeing things taper off velocity wise.

      1. avatar Wrcarmack says:

        Agreed, these would seem risky in a 16 inch barrel, this slow burning powder seems optimized for pistol use only.
        I wouldn’t be surprised to see a bullet get stuck in a carbine barrel. No thanks.

  6. avatar jesse navarro says:

    Still shooting 115g silvertips…

  7. avatar Made in America says:

    GOOD STUFF!!!!!

  8. avatar tsbhoa.p.jr says:

    10mm for thehipoints, .30 carbine. and for gawsh sake let’s see some seismic .44mag.
    the ninemil and fortyfive are priceless, but what’s that slugworth, charlie?

  9. avatar Adub says:

    Total energy calculations don’t show it much different from a fast 115gr 9mm. I’m not sure what the point is, but I’m all for more options.

    1. avatar dwb says:

      total energy does not tell the whole tale. stopping power is in part related to wound diameter, which is why you go with expanding 9mm. The wound area from a .45 is 60% larger than from a 9mm. Also, fast small diameter bullets tend to go through things without slowing down or expand too slowly. A 185 gr 9mm has the potential to expand more, simply because there is more material to mushroom.

      Think about it: a 185 gr 9mm at 950 fps is subsonic, so it has about the same energy as a 180 gr 300 blackout subsonic, but starts a 40% greater wound channel (before mushrooming), so is potentially more devastating to tissue.

      1. avatar Arandom Dude says:

        It’s not so much that you can get much more expansion, it’s that you can get great expansion AND great penetration because the sectional density is so much higher. With a lightweight bullet it’s generally one or the other, while mid to heavy bullets deliver both. Norma claims that their new 108 grain 9mm load is the most expanding 9mm load there is. I saw a test of it, and it pretty much is, right up there with top-shelf .45s- but it doesn’t penetrate. I think this seismic stuff might be overkill, but we’ll find out.

        1. avatar dwb says:

          I doubt its “overkill” any more than the venerable .45 is overkill. Peoples expectations of a handgun are too high.

        2. avatar billy-bob says:

          Maxim 37.
          There is no overkill, only open fire and I need to reload.

        3. avatar PeterK says:

          @billy-bob So much ys.

      2. avatar Arandom Dude says:

        What I mean by overkill is this: it’s not much slower than a 147 grain and the case volume available for powder is much lower, so the wear and tear and recoil are probably going to be substantially greater than with regular defense ammo. Existing mid to heavy weight loads can already deliver excellent expansion and penetration, and I’m skeptical about whether this Seismic stuff can do more than, say, a 150 grain HST.

        1. avatar Jeremy S. says:

          Felt recoil was most definitely not greater than typical 115 grain hollow point ammo.

      3. avatar drunkEODguy says:

        the heavier, slower, larger rounds should also have more energy transfer at the price of penetration, although that penetration penalty may be fairly small and negligible.

  10. avatar dwb says:

    Wonder how the 9mm perform in an 8-10″ barrel and whether they stay subsonic.

  11. avatar RA-15 says:

    I will have to get some , try them in my pc carbine.

    1. avatar Tom in Oregon says:

      Agreed. Gonna have to mix up some gel for testing.

      1. avatar uncommon_sense says:

        Hey Tom,

        I see you commenting more lately. Does that mean you are doing well recovering from your stroke? (I sure hope so!)

  12. avatar Matthew says:

    Would definitely be interested in getting some more ballistics info on these rounds.

    1. avatar Victoria anguish says:

      I agree, bring it on .an….cant wait to see this

  13. avatar possum says:

    And I thought the 9 mils claim to fame was it’s 250 fps over the .45’s.

    1. avatar California Richard says:

      Capacity, weight, ergonomics…. 35 years of real world data compiled by the FBI shows no terminal ballistic differences between .45 and 9mm. 10% gelatin and mathemagicians may say different, but the data from dead and wounded humans say there’s no difference.

      1. avatar tdiinva says:

        There are too many factors to claim caliber makes no difference. If you really believed handgun caliber makes to difference you would use cheap FMJ over expensive JHP. You aren’t going to mugged in a crowd and JHPs will fly through drywall so you have more to worry about from a miss than a through-and-through.

      2. avatar yolo says:

        in that case lets load up that ruger 1911/22 because the same studies you are citing say that .22lr has killed more people that any of them.

        1. avatar jwm says:

          It has. .22 was also the preferred poachers weapon in my neck of the woods and farmers have used it to put down large animals. I’ve seen cows, pigs and horses put down with the .22.

          In my youth I knew any number of folks, including a few that had killed their fellow man, that were comfortable carrying .22, .32, and the short .38 S&W.

          Modern folk are heavily influenced by the media. They picture themselves caught up in a buddy movie with Arnold and Sly and Bruce.

          The reality is that in a simple citizen, not police or military, DGU any functional handgun in any readily available caliber will do. I prefer center fire to rim fire just because of the slight edge in reliability that the center fire has.

  14. avatar possum says:

    Jeremy’s got a cute giggle, that guys having way to much fun.

  15. avatar former water walker says:

    Interesting!!! Slingin’ heavy lead. I’m officially intrigued😄

  16. avatar Matt o says:

    I’m very interested in this. Actually im all for normalizing subsonic 9mm so I can enjoy my can to the most.

  17. avatar doesky2 says:

    Yikes $1.38.
    How many rounds do you test fire before in your EDC before you’re confident that its reliable.
    Most people rould probably say at least 50 or more likely 100 rounds.
    No thanks.

    Last week I paid $0.40 for HST 147.

    1. avatar uncommon_sense says:


      I was thinking the exact same thought.

      Personally, I like to see 200 rounds cycle without any problems before I will stake my life on a cartridge. That would cost about $276 not including shipping, ouch!

    2. avatar tdiinva says:

      That’s what people say but it’s not true. There is no reason for a previously broken in firearm to choke on the 51st round if it ate the first 50. Any failure after that is going to be a magazine issue or a generic gun problem. Any ammo issue that I have had usually manifests itself by the second magazine.

      1. avatar uncommon_sense says:


        First point (non-statistical in nature): maybe people who wanted to shoot 200 rounds without a failure were shooting handguns that were not yet broken in?

        Second point (statistical in nature): what confidence level does shooting 50 rounds of a particular ammunition without a failure achieve? Saying it another way, what is the probability of a failure if 50 rounds functioned properly?

  18. avatar jwm says:

    2.5 ounce slug? “Yea, tho I walk thru the shadow of the Valley of Jurassic World I shall fear no evil. For Thou hast provided me with a supersonic bowling ball to throw at angry critters. Amen.”

    1. avatar uncommon_sense says:

      That there was really funny jwm!

      I tip my hat to you, sir.

    2. avatar Perry says:

      JWM, you made me look up Monty Python’s “Holy Hand Grenade of Antioch”, which was applied to a fearsome critter with big teeth.

      The gist of Seismic Ammo’s message is to combine a small amount of slow-burning powder with an oversized amount of lead. As a reloader, this is information I can use.

      1. avatar jwm says:

        Python is always relevant.

        1. avatar Geoff "Bring the EDIT button back, will ya, TTAG?" PR says:

        2. avatar possum says:

          That made me laugh, three times, the number was three, no more no less, not four nor five, the number was three

        3. avatar BobS says:

          Python 2.7 will soon be of only historical relevance.

  19. avatar Mark H says:

    I still want to know the velocity of the .45 acp.

  20. avatar DaveL says:

    A 2.5oz shotgun slug? Sweet Jesus. You could probably knock someone out cold just throwing that by hand.

  21. avatar FB says:

    Just shoot a .40S&W or 10mm.

  22. avatar BobS says:

    The glossy sales sheet correctly notes momentum is linear with both mass and velocity (p = m * v), but kinetic energy varies with the square of the velocity (KE = .5 * m * v^2). And a bullet’s purpose is to deliver energy at a distance, not to have momentum.

    1. avatar RedOwl says:

      Maybe they are taking “knockdown power” literally. Momentum is always conserved in collisions whereas mechanical energy gets spread all over the place – heat, projectile deformation, target deformation, etc.. So, if you shoot a wooden block with a bullet then the resulting velocity of the block/bullet combo is V2 = v1*[m1/(m1+m2)] . The vast majority of the bullet’s energy goes into deforming the block and bullet. In other words, more momentum equals (linearly) more velocity imparted to the target. Of course, the wound is a lot more important than the “knockdown” but that won’t sell bullets.
      My physics professor in college demonstrated this in class with an actual rifle and block. Try getting away with that in 2019!

    2. avatar uncommon_sense says:


      While your physics equations are correct, your conclusion with respect to typical handgun platforms is incorrect.

      Here is the skinny on terminal ballistics for the overwhelming majority of handgun platforms:
      (1) Handgun bullets are travelling too slow to cause hydrostatic shock or other exotic wounding mechanisms.
      (2) Handgun bullets therefore incapacitate through blood loss or mechanical disruption of central nervous system.
      (3) For a given caliber, velocity, and expanded bullet size: the greater the mass of the bullet, the greater the penetration — and hence a greater probability that the bullet will reach the central nervous system or cause even faster blood loss.

      So, in this case of 9x19mm Parabellum where the heaviest bullet up to this point was 147 grains with a typical muzzle velocity of 975 feet-per-second, Seismic Ammunition’s 185 grain bullet with a muzzle velocity of 950 feet-per-second should penetrate deeper and therefore provide a greater probability of reaching your attacker’s central nervous system or causing faster blood loss.

    3. avatar Texican says:

      Bobs, a bullets purpose when fired fired into an animal or human is to cause damage. In hunting it’s to cause rapid humane death. In a human it’s to cause them to stop doing the thing that required you to have to shoot them. Energy, momentum, bullet materials, velocity, etc. are just factors that we consider to get the result we want. An arrow fired from a bow will do the same with nowhere near the energy as will a knife with next to zero energy. Seismic ammo is another way to get the result we want. Maybe better, maybe not. I think their ammo would be great for hunting or self-defense against animals or unarmored humans especially if they used hard cast bullets and made some with a flat nose. Their bullet weights would actually go up without a hollow point! I prefer Lehigh Xtreme Defense bullets loaded by Underwood Ammo in a handgun for EDC but would use their Xtreme Penetrator in the woods. Have a great day!

  23. avatar DaveDetroit says:

    180 grain .357 readily available at over 1400 fps for the win!

    1. avatar possum says:

      And you can play Russkian roulette with it. That is if you wanted too

  24. avatar ozzallos says:

    Dude, that 325gr .45acp offering in the small print. That’s almost a 45-70 in my hand.

    1. avatar little horn says:

      no its not. jesus. its not complicated. the acp cartridge is not going ot hold anywhere NEAR the powder to push it to 45-70 speeds. you would have to hollow out the projectile which is counterproductive. this is so fucking stupid.

  25. avatar raptor jesus says:

    These guys lost me as soon as they started using pseudoscience terms like “knockdown power.”

  26. avatar Elaine D. says:

    $1.38 a round? Dayum…

  27. avatar TommyJay says:

    I’d worry a bit about proper cycling with a typical longer barreled 9mm handgun.

    Most are short recoil actions with either a Glock style or Hi-Power/CZ style unlocking cam. These usually allow about 3.5 or 4 mm of recoil before unlocking, before which the bullet should be out of the barrel.

    Roughly, the center of mass of all the moving parts stays fixed as the bullet accelerates down the barrel. The longer the barrel, and the heavier the bullet, the more the slide and barrel must move backward before the bullet exits. I think for some guns, a 147 gr. bullet already has the barrel moving back about 3 mm or more before the bullet exits. So possibly, the cam is engaging and tilting the barrel with the bullet still in the barrel, if the barrel is 5″ and the bullet is 185 gr.

    1. avatar Jeremy S. says:

      I was on target at 20 or 25 yards through that HK USP. POI was close enough between the 115 grain stuff and Seismic’s 185 that I couldn’t tell a difference on the steel silhouette.

  28. avatar little horn says:

    LMAO. so many gimmicks. wow.

  29. avatar TX223 says:


    1. avatar Jeremy S. says:

      That’s kinetic energy. Momentum is just mass x velocity. There is plenty of debate in the shooting world as to which matters more when speaking of self-defense pistol rounds. I think it’s well-accepted, though, that heavy-for-caliber provides deeper penetration even with identical expansion as a lighter, faster projectile. It also tends to lose less velocity as a percentage of its original velocity when moving from a long barrel to a short barrel (e.g. duty-sized 5″ barrel down to a sub-compact 3″ barrel). The trend for the last at least 7 or so years for self-defense and duty pistol rounds has been heavy-for-caliber for better penetration due to the higher sectional density plus less trajectory deviation when encountering objects.

  30. avatar jt says:

    I hope their customers have adjustable sights! Because those are going to hit way high.

  31. avatar mark s. says:

    Got to try this in my carbines .
    ……..and my pistols , but , Carbines for sure .

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