For what it is worth I'll share a little story, a buddy some years back purchased a heavy barrel 220 swift at a gun show with a 1.250 cylinder tube, maker was unknown, he was told the gun was a real shooter, one can only guess just what that meant, since I had a bore scope he brought it to me, it looked pretty sorry, throat washed out and badly fire checked, the gun grouped about a inch with several types of ammo, it was decided it needed a new tube, that old barrel was 30 inches long, I cut 6 inches of the chambered end and fitted it to a blue printed rem model 7 action, I chambered it to 22 rem Br with a standard neck, I recrowned the barrel and fitted it to a six enterprise thumbnails stock, at 22 inches this gun shot just about everything under 4 tenths, 40 gr noslers bt's to 65 gr bergers, today this it's one of my favorite squirrel guns, after 3000 rounds it will hold its shots to a 1/4 if I do my part, I cut the chamber stub in half, one could see the old rifling but even with a rental pick i could feel the old rifling, I'd say cut back rechamber and recrown.
