I have three Vaquero' s in 45colt, one of them is a Bisley.
They all shoot great, especially since I bored the cylinders out to fit the .452 bullets.
Don' t know why Ruger makes the front of the cylinder smaller than the bullets.
Manson makes a reamer that you can buy from Brownell' s. I paid for mine by doing other peoples cylinders at $20 a piece.
It will also stop a lot of leading in the forcing cone and barrel. (I only use lead bullets)

Good luck