What makes "permanently attached" extension
I'm nearly done with my SAS Sten Mk 3 kit (nice conversion kit, BTW), and I hit a nagging question.
What constitutes a 'permanently attached' extension? If I weld onto the barrel, that's fine, but my welding skills aren't super, and I'm worried about damaging the bore. What about welding the extension onto the front trunnion? Does that count? The whole reason I ask is that I'd like to remove the extension when I get the paperwork done and approved for an SBR, and I don't want a junky barrel or damaged barrel. Welding on the front trunnion would be easier to clean up for an SBR if that's legal.