I have a 30" barrel on my Browning Mountain Rifle that was re-bored to 58 with a 1/66 twist for round ball shooting. This gun shoots 120 grns of 2f into 2 1/2 inches about 1" low at 100 yds. The mid-range trajectory at 50 yds is 2 1/2 " high with about a 1-1/2" group (all from the bench) I clocked this loat at just over 1600 ft per second. Not fun to shoot from the bench, but this is a hunting gun not a bench gun. I also have a .58 big boar barrel for my renegade with a 1/48 twist and 27" barrel. It likes 80 grns of 2f for a round ball target load, but 110 grns for a round ball hunting load. 58's are just fun, and who doesn't like putting big holes in paper or game?