Suomi KP31 & Swed 37 SMG KITS

KP31 Suomi SEMI AUTO HEADSPACE pattern 9mm Barrel 16" Threaded 1/2-28

16" barrel for Semi Auto KP31.   Works with slant pattern KP31 shroud.  Will work with compensated shroud if the exit hole is opened to .635".   HEADSPACE on Closed Bolt Semi Auto Guns vs Open Bolt / Fixed Firing Pin Blow Back...