small primer pocket hole size

heydavemd

Sergeant
Full Member
Minuteman
Aug 11, 2009
340
0
69
SW Colorado
I was prepping the primer pocket of my 6.5x47 Lapua, and noticed that the flash hole is smaller than in my large primer rounds. I talked to someone at midway, and they said that there is only 1 size prep tool ( I currently use the sinclair), and I noticed that I make the hole larger when I use the tool. Will having a slightly larger flash hole change the burn characteristics of the powder and affect accuracy, or will I be better off making all the flash pockets the same size (but larger). Thanks in advance
 
Re: small primer pocket hole size

Russ Haydon offers two different tools. I would call them... they know their stuff. In fact, for LR primers, Lapua has a different pocket than the other makers, which I thought was interesting (not a different flash hole, but a different pocket size... I bring it up because I found out from talking to them).

If you are using Lapua brass, you are doing yourself a disservice by deburring flash holes. If you find a piece of Lapua brass with a burr, throw it away. I think I have seen one with a burr once, but I can't confirm. FC and Winchester tend to have burrs as a rule, so these definitely require uniforming. German Salazar did some testing once and found that deburred Lapua flash holes actually performed worse (in SD and ES) than untouched flash holes. if it ain't broke, don't fix it.
 
Re: small primer pocket hole size

It's not a real problem. Some cartridges utilizing small primers, i.e., PPC and 6.5 Grendel have small flash holes and some are not uniform and the decapping pin will get stuck. There is a .062 flash hole uniforming tool that is available. I do insure all the flash holes are uniform. The more uniform and same standard everything is the greater the accuracy and consistency of your loads.