If you don't have the chuck that holds the case by the rim you can make a jig by cuttin two pieces of hardwood (1x2) to the same length, clamp them together and drill a hole between them that is just under the diameter of your case at the rim end, then while you have a case in the hole (that is half in each block) align what will be the bottom and drill 1/4 inch holes on either sid of the case for 1/4 inch bolts and nuts.
To use it just put the case in the jig, tighten the bolts, put the jig in the drill press and drill the flash hole to the proper diameter.
I sometimes drill out primer pockets to use shotgun primers to fire air rifle pellets. The decapped pocket will center the drill well enough for this job. Clamp it in a vise and run her on through.
There are better ways to do it. Lathe or compound vise in a drill press. Even a simple drill press vise that you locate with the first case under the drill and then clamp, but they ain't really necessary.
And if he is talking about flash hole uniforming like the bench rest boys do, there are special tools for that.
I chuck a drill into a drill press, run fairly fast, and feed the case to the drill in bare fingers. This allows the case to float and center on the drill and produce a more uniform hole.
Someone will surely chime in with Wolfe's finding on drill size; I forget.
To prevent mixing cases, I mark my modified .45-70 cases by rolling them under a mill ******* file to knurl the rims.
Cheers from Grayest California,
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