Easy to use, hand turned reamer opens the cylinder throat to a uniform diameter for best accuracy with lead and jacketed bullets. Removable pilots let you select the correct pilot for the closest possible fit to individual chambers. .45 Caliber corrects out of spec, smaller-than-bore-diameter cylinder throats on .45 Colt and other .45 caliber revolvers. Opens throat to .4525". Provided with .4480" diameter pilot. .44 Caliber fits .44 Magnum, .44 Special and .44-40 revolvers. Opens throat to .431". Furnished with .4270" pilot. .357 Caliber from .3545" to .357". Open the throat to .358". .357 furnished with a .354" pilot. Pilot Packs contain six additional pilots in .0005" increments. .45 Caliber from .4485" to .4510" .44 Caliber from .4275" to .4300".