When new brass is manufactured, burrs are frequently left on the inside of the flash hole, which can cause erratic ignition. Precision shooters deburr the flash hole from the inside to improve powder ignition. This operation only has to be performed once in the life of the brass casing.
This handy tool automatically locates the hole and quickly removes the burr. A self-centering pilot collar with an adjustable stop centers the tool and prevents the removal of too much brass. Fits .22 caliber cases.