That's a big +2.
Unlike automatics, almost all critical revolver parts are individually hand fitted at the factory.
Cylinders just don't "drop in" without some fitting and careful gaging and checks.
Just because the cylinder will snap into the frame is absolutely no indication that it really fits.
Among other checks and adjustments, the new cylinder assembly has to be checked for:
Cylinder end shake.
Head space.
Barrel-chamber alignment on all chambers.
Timing on all chambers.
Barrel-cylinder gap.