I'll add that ALL my Pietta C&B revolvers have forcing cones added with the Brownells 11 degree forcing cone tool.
A few of my Uberti's have been modified, too....including my favorite pair of 1860's, which have proved to shoot very reasonable groups and in my best days of CAS, hitting a playing card with 5 shots at 50 ft was common...I used to pass signed cards out to kids at reenactment gunfight shows. I have recently modified a Pietta Spiller & Burr with before/after groups which has shown good improvement.
My unfired Colt Cavalry set..no, I haven't cut...nor my Colt 2nd gen 3rd Model Dragoon which is not NIB.
I do not routinely cut revolvers, such as my antiques, nor my Uberti 1860 RMs, or Open-top (all .44s) as these revolvers have smooth, even forcing cones and have proven performance that suits me.
Several of my C&Bs have also had their crowns smoothed...actually added crowns to these problem children as a rough bore at the muzzle is hard on accuracy.
Just my opinion...and a few things I've picked up along the way at work.
Slim