I had Thompson Machine build me an 8 1/2" long 1 1/4" OD silencer for my GSG-5P Pistol. I'll permanently attach it to the gem-tech adapter at the front sight for a total of 16" overall and i'll add a stock. No SBR's in my state. The silencer monocore removes from the front of the can for cleaning so I dont have to remove the tube or rear cap from the rifle and the can comes with a tool for dis-assembly. Tube and rear cap are steel and the monocore is anodized aluminum and the thing is probably strong enough for a .223. Cost me the grand total of $160 WITH shipping for the silencer plus the obligatory $200 NFA tax. Should have the form 4 cleared any week now and i'll post a pic and videos. Heres a pic of the silencer core on my dealers kitchen table.