Chamber reamers wear, get dull, and need resharpening.
When resharpened, they tend to cut undersized holes, and become eventually become unserviceable.
For whatever reasons, Ruger revolvers have a reputation for having undersized (tight) chamber throats (that part of the chamber just ahead of the cartridge case).
Most revolvers are less accurate when the barrel groove diameter is larger than a chamber throat.
HTH
John