I shorten the receiver, bolt, magazine, and firing pin on Spanish actions by about 3/4" and make rifles that use .223 or 7.62 X 39 based wildcat cartridges. They're light, handy, and very accurate. They get a lot of comments like "What in the world is that action?" at the firing range or by the hunters I meet in the woods.
Jerry


Ignorance can be fixed. Stupid is forever!