This is a wildcat cartridge, one that hasn’t been adopted by any major manufacturs. It’s made w/ a 10mm auto handgun round’s brass case and a .338 caliber precision rifle bullet.

Some will look at this cartridge and see an unholy amalgamation of brass, copper, and lead. But this cartridge was actually designed to work like .300 blkout. With a slight twist.

Unlike the .300 blkout this cartridge is chambered in .338 meaning it can get heavier 300g bullets.

Practical? Probably not. But does it look funny absolutely.

It also notably is shorter in length than 8.6 blkout meaning it can still fit in guns designed for 5.56x45.

  • @Tangent5280English
    6•1 year ago

    What does this mean for ballistics? I’m guessing you can’t cram in the normal load in those smaller casings?

    • @FireTowerOPMEnglish
      6•1 year ago

      Here’s someone load data I found.

      Load data: Bullets 250gr and below sit at 2.10" COAL, >bullets heavier than 250gr, seated at 2.20"

      250gr Lapua - 9.3gr Lil’ Gun @ 2.10" COAL

      300gr Lapua - 9.1gr Lil’ Gun @ 2.20" COAL

      Hornady GMX 225gr - 9.2gr Lil’ Gun @ 2.10" COAL

      Barnes TTSX 225gr - 9.2gr Lil’ Gun @ 2.10"

      They estimated 900-1000 fps

      With subsonics if you want to increase impact on target you’ll have to increase the weight of the bullet as you can’t increase velocity past the sonic barrier. Otherwise it’s no longer subsonic.

      I’m guessing that because they’re using a .40 cal case on a .338 cal bullet they have just enough space for the powder. Most cartridges are no where near full, but this might be.

      I think fitting into an AR-15 action was a desired design trait and if you’re going to shoot .338 rifle bullets your AR you’re kind of stuck with a short case length if you still want to fit.

      • @[email protected]English
        2•11 months ago

        Fitting into an AR-15 action makes this really interesting; it’s like the .50 Beowulf in that it’s clearly going to be single stacked in a magazine and it’s going to pack a really big punch. I wonder how the ballistics are within, say, 200 yards (183 meters or so) as the size of the bullet would make it really interesting for hunting larger game. If it’s really accurate out to 200 yards, it could likely knock down anything in North America ethically. The suppressor for this guy has to be a big boy, either in length, width, or both.

        • @FireTowerOPMEnglish
          1•11 months ago

          I haven’t heard much in regards to hunting with this round due to it being not very popular. But the creator of the new 8.6 Blackout rounds has taken cae buffalo w/ a 10in barrel.

          8.6 Blk being essential this same concept on a 6.5 creedmoor case for AR-10 length actions.

          Also the suppressor thing is a challenge. Most commercially sold cans are .30 caliber so the .338 caliber rounds won’t get along to well with those.