The two groove barrels will shoot good with groove diameter or slightly larger bullets. The one' s Ive shot were about as accurate as the four groove barrels. You should slug the bore and mic the slug to find the groove diameter. Linotype is an alloy of about 2% tin, 12 % antimony, and 86% lead, or something real close to that. I found 1500 lbs of it in the basement of a print shop here in town about twenty years ago, but you will be hard pressed to find any type metal these days. Try Bill Ferguson www.theantimonyman.com in Arizona. Or you might locate the metals from a base metals dealer near you and alloy them yourself. To make the alloy you will need something that will generate alot of heat. If memory serves, antimony and lead will alloy at about 1500 F. Quenched wheel weights will be as hard as Lyman #2 alloy though. Thats much easier to find. I think Ferguson can answer your metals questions, and the cast bullet association has a good magazine with how to articles on every cast bullet subject imaginable. The NRA used to sell a book by C.E. Harris, cant remember the name of it right now, and the Lyman cast bullet handbook are good sources of information.