Quote:
Originally Posted by Snaquebite
Agree. And based on that the burn distance down the barrel would even be shorter. Correct?
|
It is, but the standard powder for the M193 and M855 loads is optimized for a complete burn in a 20" barrel.
The standard 5.56 powder charge will not completely combust in a 14.5" barrel of an M-4, much less anything shorter. It doers not burn in the first few inches of the barrel. Hence the first round designed to work better with the carbine, the MK 318 MOD 0 “Cartridge, Caliber 5.56mm Ball, Carbine, Barrier”. That round does have a faster burning powder charge.
Quote:
Originally Posted by JHB
TR, Yes I handload, and I have thought about (cautiously) working up a load using pistol powder. I know there has been great discussion on this practice to build subsonic loads for the 5.56 community when using cans but still enough back pressure/gas to operate the action. IYHO, do you think SUREFIRE is capable of handling this pressure and if so have you heard howmuch wear is "too much" before a rebuild/replace of a can is warranted? I am not going to use the SBR suppressed all the time but would like to have a "bench mark" going into it so that after many hours of making noise or at least reduced noise while drinking with the TS, I will know when enough is enough.....LOL.....
|
I would NOT use pistol powder in a 5.56 rifle load. I would search the manual for 5.56 loads, and then cross-reference with the powder burn rate to select the fastest burning powder. Alternately, if you can find loads listed for the TC Pistol, they may have better burn rates for the shorty barrel. IMHO, there is little point in a sub-sonic 5.56 round. You are basically using a heavier, jacketed standard velocity .22LR round. With a good, well-running .22LR conversion unit, I have had no problems with getting good functioning with the Surefire 5.56 cans. It will put a lot of lead into the can, however, and I would not make a habit out of shooting it thru any can other than a dedicated .22LR suppressor. I probably have several thousand rounds thru my Surefire with no apparent wear, have fired a full 200 round ammo pack through one on a SAW, and seen the cans glowing well into the yellow heat range without issue, but you would have to cut one apart and destroy it (which Surefire has done) or possibly use a borescope, X-Ray, MPI, etc. to confirm cumulative wear.
Personally, I like the .300 BlackOut for a suppressed AR platform.