Buzz I would also go the bobby hoyt route back a while ago I had a dixie tenn mtn rifle that bobby put one of his .40 cal barrels in and wow was that thing a tack hammer. I also had one of green mountains drop in .58 cal replacement barrels it was not so good it seems that gm put a few barrels out there that weren't drilled properly through the ignition passage way and would hang fire and guess which one I had when it did discharge properly it was accurate but most of the time it was like a bad flinter even when bone dry & spotlessly clean. I had an idea it would be fun to use it with minnie balls but it just wasn't to be.