Since just after 86, I have had quite a number of B&G registered bolts come and go in numerous configuration for minis and micros.. Cut down slotted full size with and without feet, mini group bolt with and without feet, mini IMI with and without feet, micro semi with welded lip. The only configuration I don't remember having is a closed bolt full size semi with welded lip but I have seen a couple. I believe with the frenzy right before May 86 B&G was registering any and everything they could get their hands on. With that said, there has been a handful over the years that I have looked at that gave me pause for one reason or another, and I passed up. Been a huge fan of the uzi since my first purchase in 85.