The bolt on my two Pietta 1858 Remingtons drop just as,or slightly before the cylinder fully rotates into place.Just about every detail on those revolvers is outstanding.
As far as barrel gap and end play it varies from cylinder to cylinder and frame to frame in my experience.Ive seen as much as .004" difference in the OAL of the Pietta 58 Rem cylinders.
What I did was buy a few spare cylinders from Cabelas and measured the OAL's,then compared them in each of the revolvers frames until I got a good of fit/tolerance for each of the revolvers.Then had the cylinders laser engraved with the serial number of each of the matching revolvers so they dont get mixed up.
One of the Rems had alot of end play with the original cylinder that came in it,and the other was a bit tight.So swapping the two original cylinders was an immediate fix as well.
The barrel gaps on my 58's are .004" and the other is .0075".I dont have any cylinder bind issues as I swap cylinders to reload.I wipe the cylinder faces off before I drop them on the loading stand so they are cleaned between uses.
All my Colt replicas have cylinder gaps of .0075"-.011".Rarely do I see one of them suffer cylinder bind.The Walker has the .011" cylinder gap and it will run all day with a 45gr. load of ffg. with a wad under the ball and a grease cookie over it to keep the fouling soft..