Thread: Subsonic 300blk suppression issues

Hello all, I’ve got a howa mini 300 blackout, I’ve shortened the barrel to 14”, got a load that’s very accurate and subsonic (190sub-x, converted 223 brass, once fired in this rifle and resized, win 296 powder). My problem is it’s still pretty bloody loud, certainly more so than I was expecting. I’ve tried three different suppressors (brand new dpt, sonic ghost 40, and another larger diameter sonic), I’ve tried getting the loads way down to 700fps, several different projectiles at 900ish fps (all speeds verified with a chrono, definitely not supersonic). The only other thing I can think of is the dies that came with the rifle are rcbs small base, perhaps after FL sizing some of the gas/noise is exiting out the pressure relief hole on the left side of the receiver, I think I may be clutching at straws here but that’s the only thing I can think of.
Am I just expecting too much out of this round/suppressors? I was expecting only slightly more noise than a 22 but it’s more like a 22mag.
Any light that could be shed on this situation will be appreciated even if the outcome is that I’m a moron than expects too much!
Cheers!