Thread: Subsonic 300BLK , AR15 loads

Yeeap ,

Just shoot the 300blk for the 1st time today , using 9.5gr of Belmont ( WC296 ) & 220gr SMKs , speed is 1050-1098 fps, and it cycles , but the converted brass I am using is in short rubbish .
Will try 9.3 & 9.4gr , But this powder is super fine , and a bit fiddly .

This is from a 1-8 twist , 10.5 inche barrel .
with pistol gas lenght .