Mr Hoyt did a 50 to 54 cal change, rebored and rifled to 1:66 for me back in the mid 1980's. The bbl was won and chose from several items by me at a local shoot. The Numreich Barrel was a 42", .50 cal 1:66 twist barrel was a prize. There was a front and rear site mounted, 2 attempted staples in the bottom flat, the more rearward one was spot welded in an apparent attempt to firm it up. That made a slight swell inside the bore resulting in a tightened spot 2/3 the way back. You had to slam or pound the ball home. It shot well but it was still a bee...atch to clean with a jag. No problem with just towe. I was given Bob Hoyt's name, contacted him and explained the problem and HE suggested the resized, rebore solution to the problem. Took it off the stock; sent it as was; I got the barrel back in a timely fashion. replaced it in the stock as was sent and returned. I shot 5 shots from a bench rested setup, at a 25 yard pistol target set at 50 yards. 3 touching center X ring, 1 just touching at 7 o'clock on the center ring line and 1 at 10 o'clock, 2" out. I left the sights and Mr Hoyt will ALWAYS HAVE me recommend his work. Another member of the Loyalhanna Longrifle Assoc at that time, an officer took my recommendation, and had similar result experience. Just like the ol' ******* saying says: Git 'er Done!