During the manufacturing process, burrs that can cause erratic ignition are often left inside the case at the flash hole.
Redding now manufactures two different tools for removal of flash hole burrs. Both tools use pilot stops listed below.

The universal tool is for all calibers from .22 thru .338 cal. using standard (.080”) flash holes. This tool controls the cutting depth with a built-in stop that locates on the inside web of the case. A unique feature of this tool is the cross drilled hole for chip relief. Uses standard pilot stops for 3/16” mandrels.

The small tool is for .17 & .20 cal. and cases with small (.060”) flash holes. This tool does not control the cutting depth. The operator must control the cutting depth using the small pilot stops for 9/64” mandrels.