For this one I was going with a Wilson Combat AR10 carbine spring, Slashes’ extra heavy 6.5 oz buffer and a full mass carrier.
I have used slashes buffers for most of my projects to slow down the bolt speed. Has been great in my suppressed setups. To be fair, my main rifles are rifle length systems, heavy buffers, with adjustable gas blocks, and tuned to suppressor use. They have all ran great unsuppressed, though.
My worry here is that a carbine length .308 SBR would have a janky dwell time without a heavy enough buffer. Reasons I’m here lol. I don’t really mess with SBRs and I like the additional knowledge.