Where is the best place to start The Hodgdon Reloading Data Center (RDC) lists 21 different powder types that can be used in the. I'm sure it's been done before for some CQB unit somewhere. 223 is easy and there are a number of great powder choices.
Also, it's the gas port size that regulates the cycle rate etc, not springs, buffers or fairy dust. Bullet design for short ogive 'fat' bullets made for sub-sonic work means crappy BCs, relatively. Chamber throat and magazine length limitations can steal a lot of powder capacity from a round.
#Subsonic 223 ballistics chart full#
Otherwise, you're better off going with a bolt action weapon because it doesn't make any sense using the m16 platform unless you need a semi or full auto silenced weapon. A 150grn 300Blk at 2000fps needs a different twist than a 230grn pill at 1,000fps. Geeez.Ī dedicated platform would be needed because you'd have to have a specialized barrel with a higher than normal twist rate WITH an enlarged gas port so the system would cycle, but this wouldn't work with anything else and still stay together after ten rounds or so. 223 case, you'll know right away they're clueless about putting something like this together. 223 bolt rifle is a solid predator gun that has the benefit of being able to use. Oh and by the way, if anyone ever trys to tell you to put 8gr of ANY powder into a. However the SOCOM will also fire 500gr 600gr bullets subsonic for. You'd need reasonably low pressures shot from a short barrel that reach speeds between 10 fps a balancing act at best that would have to be done on a test-bench having the expectation of blowing up at least a couple receivers before getting it right.
#Subsonic 223 ballistics chart trial#
Getting the right powder would be all trial and error. That may have been accurate with most rifles years ago, before the AR-15 exploded in. 300 AAC Blackout 125 Grain Trajectory Chart. For instance, the SAAMI Spec barrel for 223 Remington is a 24 1:12 twist. I'd start with a moderately heavy hollow point round like a flattail 65, shot from a sort (12" to 16") relatively high twist rate barrel something like 1:12 to 1:17, with a relatively fast burning power. HSM Subsonic 300 BLK Ammunition, 20 Rounds, 220 Grain Sierra MatchKing, 1000 fps HSM Subsonic 300 BLK. It would seem to me that you'd need a dedicated upper to shoot subsonic.