Around the early 'Fifties I saw quite a few revolvers sleeved to smaller caliber. Many of these were Webley Royal Irish Constabulary revolvers orignially .442 RIC sleeved to take .25-20 cartridges. And a few to .22 R.F. The .22s I saw had the chamber angled slightly so the centerfire firing pin struck the bottom of the rim of the cartridge in line with the barrel.
Didn't fire any of these so don't know what that did to accuracy.