I made one of my nelspots semi auto, Its slow, heavy, and not practial, but it works, however I do need to finish some things yet but it works. The best bolt on kit Ive seen is the one that WGP made for the ranger (iirc) If you can track one down thats the way to go, otherwise you'll be scratch building it. 4 way location is the big problem, for my nelson, after much thought and a few failures, I decided that a bellcrank was the best way to go. Becuase of a slight oversight I can get 2-3 shoot burst as well in addition to semi auto, Im working on that to see If I can dial it in to where it would work reliably, if not I'll fix the issue and it will be strictly semi. Its a fun progect that I've had goin on for about 2 years now. Long story short, go for it.