Well I must admit that the two most accurate PRB guns I have own were not TC 1-48 twist guns. One is a Hopkins & Allen 58 caliber that with a really tight PRB would tear a raged hole at 100 yds the load it liked was 100grains, the other was a 54 I hand built with a green river barrel which I used in the Hawken and Mountain man competition at Friendship. But with that aside I have gotten good accuracy from the 45 50 and 54 TC 1-48 barrels I have. One of the things I have found is that it takes a scope to really find out what a gun will do at 100yds.