Hello, so I’m trying to fix up my uncles .300blk but am stumped. He just got his supressor out of Jail, a gunwerks 6 supressor. This thing runs supers great, but I cannot for the life of me run subsonic Ammo. Tried multiple Ammo brands and grains. It’s a 16” faxon 300blk. Currently on lightest buffer at A5H0. Gas block is non adjustable. It will cycle out the old round, but will not cycle a new one. At this point would it be a gas port being too small? Or something else. Any feedback would be great.