[SampleMan]

You can make ammo with faster-burning powder, intermediate between rifle and pistol powder.

And why don't they always do that? Because burning all of the powder in a 7.62x51 cartridge in 14" would do two things:

1. Increase pressures to the point that you would need a 14 pound receiver to handle it.

2. Burn up the barrel in about 300 rounds.

That's why they don't pack cartridges full of C4.

[Mmogamer]

May be a dumb question, why not make our own version of an ak-47? It’s obviously been proven to be good under adverse conditions and stuff...just asking.

[Eaker]

That's why they don't pack cartridges full of C4.

Hand loads.

5.56x45-C4

Sent a bunch to Squantos, don't know if he has fired any though.