Flatlander .54, I just bought a .32 green mountain interchanceable barrel on monday from track of the wolf and have shot about 40 rounds threw it. Buy one now! It is a very well made and dropped in with no modifcation. comes with sights, nipple and ramrod. I bought all the accesories( short starter, cleaning jag, ball ammo) for a very reasonable price. Just cleanout storage grease out of barrel and your ready to shoot. I shot touching groups at 25yds and 2" at 50yds with the open sights provided. 20g. 777, .310 hornady ball, .010" lubed remmington patch cut at muzzle.