I don't own a supressor, but logic tells me that you need to keep the velocity under 1,100 fps or you can't suppress the crack of the bullet. A .300 Blackout would certainly be a factory option, but they use a heavy for caliber bullet for their sub sonic ammo that might not expand as well as you'd like it to. In your case I'd look for more bullet diameter like maybe a .44 Special or a .45 Long Colt. You could then use a .44 Magnum or .454 Casull or .460 S&W when you didn't need it suppressed and wanted lots more cartridge or hand load those bigger ones down to Special or Long Colt velocities. Bigger diameter, softer bullets would hit harder than a smaller one at the same velocity IMO.
