300 Fireball and 300 Whisper reloading references on the web

[mak91]

For what its worth.

8.5 grn lilgun 240 grn smk

ar15 with 2 different uppers

m1s 16 inch barrel with pistol and carbine gas blocks, Bowers 9mm can:
pistol gas block open - 995 / 1012 full cycle and picked up next round
carbine gas block open - 980 / 965 bolt only came back about 1 inch and stopped.
Overall very little sound except for the action noise.

tp555 10 inch barrel with pistol gas block, aa 7.62 sd can:
1150/1155 full cycle and picked up next round.
Loud crack about 25 ft out from the muzzle but you could still hear the bullet hit the target.

8.2 grn lilgun 240 grn smk

tp555 10 inch barrel with pistol gas block, aa 7.62 sd can:
1006/1034 full cycle and picked up next round.
Much less noise than the 8.5 grn load out of this barrel but not as quite as the 16 inch barrel even with the 8.5 grn load. Not sure if its the suppressor or the extra barrel that makes a difference.