does anybody drill out their flash holes prior to priming and if so what size of drill would you use?
thanks in advance

Would not recommend drilling out flash holes, just deburr them and ream the primer pockets.

Stan

Red:
The Sinclair flash hole uniforming/deburring tool is a center drill with an adjustable stop so that it can be set to barely deburr the flash hole inside the case. It has a guide drill which measures .078". Once in a while you will find a case which has a slightly smaller hole than .078 and the uniformer will open it up to that size.

See: www.sinclairintl.com/

As Stan said, would not use a drill bit on them.
Regards,
hm

I use the Lyman unifier. Cheap and simple. Just a couple of turns so the hole has a even taper on the inside of the shell. Don't go too deep.

Ruger Red,

You may find the link below of interest...

flash hole