The future of small arms?


We always want something better. So we (as in the U.S.) spends tons of money to try and make the next big thing. (Come on eggheads, where are our directed energy rifles?)

It was recently announced that one project is this screw breach to allow for higher pressure rounds. The idea is to use something like this, along with other changes like a squeeze bore and or a collet chamber to allow for much higher velocities and chamber pressures. The article over at says that the Army’s current prototype with a 24 inch barrel drives a bullet 4,600 – 5,750 fps and has nearly double the chamber pressure of a M4.

I sorta get the feeling that small caliber high velocity has been done before, but what do I know?

I would be worried about how well the screw breach handles dirt and debris. Also how bad a catastrophic failure of the firearm is at 100,000 psi. But both those issues should be manageable with good design. The real question is going to be if it gives enough of a real world benefit to make it worth while.

Just because you make something new doesn’t mean that everyone will want to use it. IWI is making a standard rifle called the Camel to compete with their bullpup Tavor/X95 because so many markets are not interested in a bullpup.


  1. 100k psi and 5000 fps is gonna burn out barrels in like 5 shots.
    Not to mention the increase in recoil manifesting as increase in split times for rifles and decrease in accuracy for machineguns (since the army refuses to adopt a good tripod).

  2. This would certainly end my quest for a lightweight semiautomatic elk rifle.

    Which, I’m open to options if anyone has them. I’d like 6.5 Creedmoor, and under 8# if anyone has any suggestions.

  3. The concerns about dirt or something else that prevents a tight fit of the collet around the cartridge case are very real issues. Most cartridge brass starts to come apart definitively at 70K PSI, unless it has very tight support from the chamber, the breech, etc.

    With small-bore projectiles, chasing these extreme pressures is a poor return on investment – because the surface area on which the pressure can act is so small, we see less force generated by the pressure increase.

    The above comment about barrels burning up – if we’re just dealing with Chome-Moly or stainless (416 or 420) steels? Very, very true. High pressures result in fast burning throates – ask the guys who shoot .22-250 AI’s at these velocities. They burn up a barrel in no time.

    But I still go back to the basics: What problem does this solve?

    – Do these ideas make a gun more lethal? Not especially.
    – Do these ideas make the gun easier(ie, cheaper) to produce? No, absolutely not.
    – Is there a lack of weapons extant that already kill people in the situation they’re describing? No.

    This is my problem with lots of gee-whiz gun design today. Most ‘improvements’ to gun design today are solutions in search of a problem.

    • While the problems with metallurgy and engineering are beyond my ken, and granting your point about pushing a .22 caliber pull that fast not providing much benefit, wouldn’t an advance of this nature mean that a cartridge with current 5.56 ballistics would be able to be much smaller and lighter? That seems like a major advantage to me.

      • It might be smaller. Lighter – sure, perhaps a few grains per cartridge. Most of the weight of a cartridge in the 5.56 class is in the case. A 5.56 cartridge case is about 95 grains. Let’s take the best case and say the bullet is 77 grains.

        I reckon with this idea, you might be able to shave 20 grains out of the case weight. You want to keep the bullet weight (a heavier bullet has a higher Bc), so keep that at 77 grains. A typical 5.56 load has 20+ grains of powder (more like 23+ grains).

        Modulo the primer, we have a total per-round weight of 77 + 95 + 25 (eg) grains = 197. Add a few grains for the primer – call the whole mess 200 grains per round.

        OK, so let’s be generous in assumption: let’s say that we carved out about 20 grains of case weight and 10 grains of powder out of the load – total of 30 grains saved out of 200, or 15%.

        Given the trade-off in reliability and service life of the barrel without having a stellite liner, I’d rate this a “meh.” It’s got some upsides, and it has some downsides.

        • Thanks for the reply. A 15% weight savings seems pretty significant to me. Upping a standard soldier’s ammo capacity by 15% isn’t nothing, not to mention getting 15% more cartridges into a magazine and the logistical benefits on things like air transport into hard-to-reach combat zones and such.

          And a 15% smaller cartridge may also mean a smaller firearm.

          It seems like if this is feasible, improved metallurgy may pick up some slack on the barrel end of things. Who knows. It’s more interesting than another 1911 or AR-15.


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