For a multipurpose 9mm subgun suppressor that can also handle non-SBR rifles, the YHM R9 is really solid.

It has a 16" minimum length restriction on 556 and 308, but seems to beat out the MG7k 358 on all other metrics.

It's a little shorter, 2 ounces lighter and has 2 more baffles, which helps reduce sound with 9mm.

R9 gas blowback does not seem to be an issue on blowback AR9s we've used with 4" to 8.5" barrels and appropriate buffer weights.