I just found out I really need an integrally suppressed Yildiz .410

I might look at Liberty. Their Leonidas line is built on AR platform barrels but they might do shottys as well. I did some business with Well’s Custom Gunmakers in PA several years ago and was very pleased with my products. But I think I’d much rather do a 20ga suppressed than a 410ga.

Might consider a 12….just because it’ll kick like a 28ga and be just as quiet. I’ve got a metro barrel, and dove loads are crazy quiet, just adding that.

You can just go buy a suppressor for a 20 or 12 if you're willing to tote it. Does the larger gauge do anything for you if you're loading subsonic?

Call and talk to David Saylors at Liberty suppressors. If anyone can do it he can.

Ol popgun may have some suggestions as well

Larger gauge gets you more payload and more energy at subsonic, with same sound signature. If you don’t need ‘more’, then sub gauges have the same sub gauge advantages/disadvantages as always.

If I was to suppress a shotgun, I would get an integral barrel. Seems too unwieldy otherwise. Phoenix Weaponry sells them off the shelf for Mossberg 500's, and they do custom work for other shotguns.

https://www.phoenixweaponry.com/store/Cindy-Integrally-Suppressed-12-Gauge-Shotgun-p169585731

Pump probably makes more sense i guess.