Which ammo for which rifleing? Colt m4 and Sig sbr? AP ammo?

[alfred10]

What grain ammo will function best in the rifleing of the Colt 6920, and 6921 (14.5 inch), as well as the Sig SBR 10 inch rifle? Will all of these rifles feed commercial hunting and target ammo? Whats the best cheap yet accuret stock pileable range ammo? Will the above rifles feed wolf without an issues? What grains will if any will jam the rifles?

Is the military green or black tip AP ammo? If not, what does it do that win white box .556 wont?

[Belmont31R]

They should all feed 5.56 ammo.



Its not a good idea to shoot sub 55 grain HP ammo as the bullets can catch on the feed ramps, and push the bullet back into the case. Ive had this happen a few times before I knew any better.



Prvi match ammo is a good deal for the price. Its not been as accurate for me as more expensive match ammo like Black Hllls but its better than typical FMJ ammo.


Those rifles are 1x7 twist so anything from 55-77 GR should function fine. One of the benefits to a 1x7 twist is the ability to shoot 70-77GR ammo whereas 1x9 will not reliably stabilize these rounds. 75 and 77 GR OTM has been very accurate for me in a variety of barrels. One of my personal favorites is Silver State Armory 77GR OTM 5.56. It mimics the MK262 round. Otherwise 75GR red box Black Hills is my 2nd choice.


Standard issue military ammo is M855 which is green tip 62GR with a steel penetrator. Its not not AP ammo. Actual mil issue AP is very hard to come by, and illegal AFAIK. It has a black tip. Lots of fake AP ammo out there, and its hard enough to come by in the military let alone in the civi world. M855 is a good round for traditional combat roles but its not ideally suited for HD/SD. You're better off with a TAP 5.56 T2 loading, Mk262, or the SSA ammo I mentioned above.

[alfred10]

What ammo is most durable for SHTF long term field conditions. I want to pack a few mags with ammo that will last as long as possible in field conditions. How many years will ammo last in the field?

[Killjoy]

Ammo isn't like milk, it doesn't just go bad. Assuming you store it in fairly dry conditions, it should remain good essentially indefinitely. I've shot '53 marked 30-06 out of my Garand with nary a problem. I've shot tons of 80's marked 5.56 also with no problems.