Was reading on another forum of the accuracy benefits of preparing brass. Uniforming primer pockets was touched on briefly. I have been reloading for years, but have never done anything to primer pockets, except clean them after depriming. What exactly do you do to "uniform" primer pockets, and which tool in your opinion works the best. Thanks for any help... Grant.

The purpose of uniforming the primer pockets is to get consistent seating depth. I have found this doesn't make much difference, but hey, I can use every little bit of help and it only has to be done once. I think the best tool for the job is the Sinclair model.

Jim

I find this procedure to be simple and I do believe that it adds to shot to shot consistency along with flash hole deburring. Also, this procedure should be performed every time you reload. Case material will flow into the primer pocket each time the case is fired. An easy way to check this is to try and uniform a primer pocket on a fired case that you previously uniformed. You will notice that you actually do cut out more material. I use the basic tool sold by Midway USA and it works just fine. Thanks!

quote:

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Originally posted by 338Lapua:
and it only has to be done once.

Jim

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[ 08-02-2002, 22:43: Message edited by: Shark Bait ]

I did it once...compared it to exactly loaded ammunition that I did not do it to. There was no remarkable, or even noticeable, difference in velocity or accuracy between the two...so I don't bother any more.

I'm with Steve on this one. A recent article by John Barsness profiled his second test of whether case prep made a difference in accuracy, and the results showed that the unprepped brass actually edged out the prepped brass groups by a small margin. The rifle he used was a 1/4 MOA .223 Remington. I'd say if case prep made no difference in that small of a cartridge, the larger cartridges would certainly not realize a difference.

In my opinion, a properly developed load will be largely resistant to minor differences in primer seating depth, flash hole differences, etc. Barsness mentions that if you'll measure the height of your primers you'll often see more variation there than you'll see in primer pocket depth.

I have a primer pocket uniformer (the RCBS model) but no longer use it.

Wizard

I do not uniform the pockets, however, I have found that deburring flash holes on new brass, American made, does improve things to a degree that I can see it on paper.

What a pain in the arse it is to do though!

I foundthat if you get the uniformer that sells for the rcbs trim station (about $10) it will chuck nicely into a drill. It's a real fast way to both clean and uniform primer pockets. It may very well not improve things for the average rifle but heck....you gotta clean the pockets anyhow so why not get a bonus for the same amount of work??

I've bought 2 batches of Winchester Brass (.222 & .38 Special) with too shallow primer pockects. A Whitetail (now Sinclair)primer pocket uniformer paid for it's self on the first batch. And yes, they are the best pocket cleaner made.

Bye
Jack

It is a mistake to assess the value of uniforming primer pocket depth based solely on groupsize. In tandem with deburring flasholes, a consistant primer recess of .005 to .006" will serve to assure more relaible ignition via a constant striker travel and the elimination of the occasional crunched primer in a too shallow pocket. Generally, the more uniform your brass the better, in regard to accuracy but the advantages of consistant ignition are of more immediate import, when loading for dangerous game and/or drawing conclusions as to pressure signs by reading primers.

This thread has convinvced me to start uniforming pockets if for no other reason than to achieve increased consistency. The danger is that I am rapidly running out of excuses for those bloody fliers....

I do not want to do this operation by hand. Using a power drill, what is the preferred tool out there?

Regards,

~Holmes

Hi, Holmes - I suggest getting one of those RCBS case prep machines. They save a lot of time and hold up well.