I've got a sandman-s on a dd pdw in 300 blk. I like the length and I'd rather my ears were assaulted by the resulting Db than the original unsuppressed Db. That said, it ain't exactly quiet, even with a jp silent captured spring. I've got a nomad-l in jail. We'll see if that is acceptably quiet. I don't have super high hopes though because the action cycling on an AR is pretty damn loud all by itself.

I've also got a Wolfman on a CMMG Banshee in 9mm. Even with 147gr subs it's still uncomfortably loud due to what I assume to be the action. My glock 19 with the same ammo and can is significantly quieter.

You want real hearing safe semi auto in an AR? Get a dead air mask hd and put it on a 9" 22lr ar. It won't have stopping power, but you won't need hearing protection either. My competition 9" 22lr AR is super reliable too, as long as I keep it super clean.