Anyone drill the flash hole for a consistent size?
YES
Brass Perpetration for shooting and Accuracy.
If you do a search on LRH or the internet you will find hundreds of Threads/Post and OPINIONS on the way to prep Brass.
Just had a discussion on Primer Pocket Uniformity on LRH the past few days.
You will find everything from just fire used brass without even cleaning to Prepping Brass with very high tolerances.
I have reloaded for over 50 years and went to extremes researching what the TOP Benchrest/F Class shooter do.
I can say going to the EXTREME can't hurt, but some can say that it does hurt.
One example is clean or fired brass cases.
Making a clean piece of brass removes all particles on the outside of the case.
Some say that having a already fired case with particles on the case will "HOLD" better in the chamber when fired opposed to a clean smooth piece of brass.
I can write a lengthy story on the progression of brass prep, but not here and now. If you want to discuss PM me and we can talk by phone.
For the OP answer YES I drill Flash Holes. there are several Tools on the market to accomplish this task, but we use the:
The new K&M Premium flash hole tools have a carbide cutting head that allow the brass chips to free flow from the cutter which conditions both the diameter of the flash hole and chamfers the flash hole at the case web.
I have seen Flash Holes in Brass with "Burs" the cover half the Flash Hole. Now that can direct your Primer Ignition to hit one side of the powder stack with an uneven burn. There are illustrations on the internet that show a Flash Hole that is uniform and having a cut that makes the "FLASH" hit the powder stack like a funnel effect for an even burn.
Why do reloaders use different Primers? To get a proper and consistent ignition in the powder stack.
Only goes to show that is you have the correct Primer with Ignition, the uniform primer pocket to have the primer seated in the correct depth & "Crush" and then you need to have a "Flash Hole" that allows the ignition FLASH to burn the powder stack evenly.
Some say that after a few shootings the Flash Hole will be burned to a consistent HOLE.
If you ever drilled out or cut the base of a case you will see that it is rather thick. If the Flash Hole was Punched in at an angle you will have inconsistent ignition.
To each his or her own on how much case prep you want or need.
Thanks
Len & Jill