Load some 1-1/2 oz loads of TSS #3 or #4 shot loads and pattern them through your cylinder barrel before you spend a bunch of money on barrel work. TSS shot patterns way tighter than lead shot because it is perfectly round and dose not deform when the shell is fired and by having way more pellets per shell you won't need a real tight pattern.
From KPY Shotshell Ballistics
1200 fps lead T shot gets 3.70" of gel penetration at 59.7 yards and has about 70 pellets in 1-7/8 oz of shot.
1200 fps lead F shot gets 3.70" of gel penetration at 80.1 yards and has about 53 pellets in 1-7/8 oz of shot.
1300 fps TSS #4 shot gets 3.70" of gel penetration at 78.9 yards and has about 125 pellets in 1-1/2 oz of shot.
1300 fps TSS #3 shot gets 3.70" of gel penetration at 96.8 yards and has about 100 pellets in 1-1/2 oz of shot.
