The thought has occurred to me that I might like to build a .22 rifle...with a Mannlicher style stock. Or maybe something in .223...my question is....are parts readily available..I know there are aftermarket barrels...as well as triggers....but what about receivers? Any books showing how? Am I limited to bolt action..or can I go semi-auto, non Ar-15 style.And if I am dealing with receivers I guess I would have to get an FFL...right?? (I'm thinking this could be tougher than I think.)Yes..I know I could probably buy something already built....But...think of the possibilities...