Author Topic: enlarging the primer pocket (Read 571 times)

Deadeye47 · « **on:** February 10, 2005, 08:04:03 PM »

I have read somewhere on these pages about drilling out the primer pocket on 45-70's and etc to get more spark to the powder...anyone know what size drill is best for doing this.....can one go too large???

dlemaster · « **Reply #1 on:** February 11, 2005, 01:13:23 AM »

Spence Wolf's book recommends a #41 drill bit

Regards, Dave

Deadeye47 · « **Reply #2 on:** February 11, 2005, 04:39:42 AM »

Thanks Dave!

powderburner · « **Reply #3 on:** February 11, 2005, 06:26:00 AM »

in my experiances with drilled primer pockets they work good with mag primers and heavy compression .whereas they are not too benificial to lightley compressed loads with std primers if you cannot find a #41 drill you might try a 3/32 drill ..........Dean

Ray Newman · « **Reply #4 on:** February 11, 2005, 08:03:17 AM »

Lately, Paul Matthews has written in the "Single Shot Exchange' articles extolling the benefits of swaging down primer pockets to a smaller diameter.....

In any event, Id keep carefully track of any enlarged primer flash hole, esp. if you shoot a hot or heavy White/Nitro powder (AKA Smokeless) load. You could have a primer blow back or rupture w/ such a load.

So who knows what is really better--larger or smaller? Youll need to experiment.

Deadeye47 · « **Reply #5 on:** February 11, 2005, 11:22:36 AM »

Thanks guys for the input....the 45-70's that I am enlarging the hole on are for BP only and are segregated from the Smoleless ones....I'm also going to try it on some 45-100 brass also.... Thanks again

Lead pot · « **Reply #6 on:** February 11, 2005, 05:04:24 PM »

I only drill my pockets out to the largest in a new batch of cases, so there all uniform in size and keep them together.
I tryed larger and swaged holes smaller even silver soldered the flash holes shut and made two holes like the berdan primer flash holes. If you want to try larger holes I would sugest just doing it with ten cases so you dont end up throwing all away. I found smaller holes give better consistancy in burn.
Kurt