I just finished up my M31 build, well not finished but it does run now. Need to park it or paint yet. Converting the bolt was probably the easiest part of the build to me. Your AR firing pin setup made it easy. You still make those? I had picked up 2 of them and it was a good thing I did, I ended up screwing up one. Glad you mentioned it, I was wondering about converting one to a .45. I have another bolt here that's calling my name to do something with it.