http://www.blackthornforum.com/Forum/vi ... f=35&t=115
a successful subsonic .223 load for one particular gun. kind of almost getting into the 300 BLK thing, but with the tiny bullets. the interesting quote:
here are some questions I posted on the other thread.Everyone's weapon is different so don't use this recipe and expect the exact same results. This was tested and dialed in on an AR-15, 16" barrel, 1:8 twist, mid-length gas system, with a YHM Phantom Suppressor. The cases were trimmed to 1.743" and the Over All Length (with seated bullet) is 2.220" using a Speer 55 grain HPBT projectile. 3.8 grains of the IMR Trail Boss powder is what I fine tuned. This gives me 1005 FT/s at 123 ft-lbs of energy. (In comparison a 40 grain .22lr round at 1000 FT/s is 88.8 ft-lbs)
so, if there's any interest, I'd be interested in hearing it. The 223 subsonic thread shows potential. Although the 115gr 300 BLK seems to cover the zone, not everyone has that or even wants it. but the idea opens up the .308 subsonic questions too.Interesting idea. But would you really want to rely on the spring to lock the breech? and, if you had that much spring, could you cycle it all the way?
I was thinking you would alter the buffer and spring weights.
Or maybe even use the charging handle to cycle, essentially a sequential single shot.
Or maybe this is the place for a piston gun with variable gas?
Hoping someone has this all set up and running. Wouldn't even need earplugs. should have all the accuracy and potential of 22mag or better, eh?
anybody into the .223 subsonics?
Grizz