I'm kicking around the idea of a home build using AR parts. The barrel/extension assembly will be standard fanfare, but I was thinking about pressing/pinning it into a 4140 trunnion, which in turn gets welded into a section of 4140 box tube. The question I have is that since I am planning on using the AR barrel extension, do I really need to have the trunnion heat treated? I imagine, just for safety sake the answer would be yes, but I thought I'd float the question. Oh, and does anyone know where I can get the steel parts heat treated at? Is it something I could do at home since they are fairly small parts?