I have a 94ae so it has 1:12 twist. Probably limited to 200gr bullets. The quiet 30-30 is a concept I considered around 20 years ago when I started reloading. Thought about loading up some heavy subs, then I saw the prices on heavy 30 cal bullets, they were all specialty or premium big game bullets. So I scaled back and just loaded up some cheap 124gr .311'' AK bullets on top of something like 7 or 8gr of unique. But now the 300bko is gaining popularity making cheap 220gr FMJs and plated bullets specifically designed for subsonic use available and at a typical plated bullet prices. I think I have a few hundred hornady 190gr match Spitzer bullets rolling around the reloading room that I never thought I would use. Could start there just lob them at paper to see if they hit sideways but I'm pretty sure they will fly straight.