458 socom bl length

Might want to check barrel restrictions for your suppressor, I have a Hybrid and went 16" TROMIX for that reason.

Even subsonic, 458 SOCOM is not very quiet. FYI, fun, I like mine, but realistic expectations and all.

A PDW sounds painful and I would worry about the strength of the mechanism, but have not tried it.

I would go longer rather than shorter, I think an 8" would be a flamethrower. My 16" with can is still quite handy.

I have a 12 inch tromix. Runs great, but as said above, is not particularly quiet with any loads that run the action. Pistol length gas with adjustable block, have tried a couple different cans.

A 16 inch bolt gun with fast powder or longer ar15 barrel will make less noise of course... just depends on priorities.

When I got mine, the 12 inch barrel was supposedly more reliable than going short like 8 or so. Not sure if still true though.

Very happy with the 12 and would definitely go that way again. It's great for deer hunting up close in brush here.