A damaged or poorly-cut muzzle can really hurt accuracy; sharp edges on revolver cylinder chamber mouths can cause rounds to hang up going into the cylinder - a real problem when using speedloaders. Cure both problems with this cutter.
Big Book Catalog, Issue:69, Page:462
SPECS: Cutter - 3-1/4" (8.25cm) long (except .17 caliber cutter - 2-3/8" (6cm) long). 1/2" (12.7mm) or 5/8" (15.8mm) diameter.