I have a available 30 cal can and am interested in a supressed bolt gun. My main calibers in order are 5.56, 7.62x39, and 300 blk. I am very interested in the 7.62 ruger American, and like that it uses mini30 steel  mags. Does anyone regularly shoot subsonic 7.62 from this platform? Is the transition to super drastic?Ammo is readily available but I just don’t know how accuracy would be.

My end goal is a rifle around 2 moa sub super with good ammo, that can run My piles of junk ammo in shtf.

Nothing? Bump

Hope you like a 26" drop at 100 yards.  If it's for hunting under 200 yards, it's OK.  But after that, you'd be better off with a mortar.

I've been working on my CZ 527 suppressor ready in 7.62x39.   I haven't done any subs yet.   It likes the Wolf Military Classic FMJ's shooting them about 1.5 inch at 100 yds.  Fed American Eagle brass FMJ's almost 3 in.  After some work I have a hand load with 125 Sierra Pro Hunter going into an inch.  If you load, do yourself a favor and buy the Lapua brass from the start. I tried to reload the Fed cases and they had terrible headspace issues (too short) that led to poor accuracy and misfires.  I'm not sure how subs are going to work, mine seems to like full cases loaded near max.  Currently I am shooting a little over the max charge of CFE BLK (according to Hodgdon) with no pressure signs and recoil is mild.  I should have my load settled tomorrow and then I'll get the crony out and check my velocity and post some results.

I run 6.0 grains of Trailboss with 123 grain .311 plated Berry's bullets.  Good accuracy and subsonic, around 1070 fps.
RAR 7.62x39 .

A 9mm carbine would accomplish a similar goal and the bullets are better suited for expansion at those speeds. You are talking 212 vs 250 BC but the terminal performance of off the shelf bullets isn't even in the same ballpark.

ETA: I see you mentioned a .30 can. I will amend my recommendation to get the 9mm and the appropriate can ;)

Not sure the standard-twist barrel will stabilize the subsonics to get your 2MOA accuracy goals.  

You're better off getting a 300 BLK, as you're looking at the exact same ballistics for subsonics and that's what the round/gun was purpose-built for.

I shot some brown bear subsonic out of my RAR this past weekend. They shot about 6” low and 6” right at 100 yards on a rifle sighted in with standard 123gr 2400 FPS 7.62x39. Grouped about 2-3” at 100 but my rest wasn’t the best. They were very quiet.

I think I run 9.5 grains of 296 with 180 grain bullets. You may find better results by opening up the flash holes. I don't remember how much off the top of my head.