Why I Clean Primer Pockets

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  • Last Post 13 July 2009
CB posted this 22 October 2007

Questions have been asked before about primer pocket cleaning; why some do and why some don't? Duh!

I clean mine to get all of this crud outa the primer pockets.  This picture shows residue after 25 rounds that were cleaned.  I just happen to use Federal 210s and I doubt if any other primer brand is any cleaner.  Primers seat reasonably firm for me and I don't want to break any more of my Lee primer seating tools. If I had loose fitting primers, maybe I'd leave the crud in? But I don't.

I cut all my primer pockets with a Sinclair pocket uniformer because I believe in having the primer seated to a uniform depth and seated with uniform pressure all the way in for the primer to work like it is meant to against its internal anvil.  Running a primer down over previous residue and crushing the primer down over crud makes no sense to me.  :?

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Tom Acheson posted this 30 October 2007

Agree with Dan. Clean the pockets every time the old primer is removed.

New lesson for me recently. I was loading some brand new WW 223 cases using R-P 7.5's. The gun is a break-open pistol and the action just barely would not close. Turned out (after checking other possible flaws such as case length and shoulder and bullet position) that the primer was not set into the case deep enough. It protruded just a 0.001” and this was just enough to exhibit a chambering default. Use of the Sinclair pocket “reamer” solved it. Now they are about 0.004” to 0.005” below the base of the case. These are fire-forming loads and this is the first time I've encountered too-shallow of a primer pocket in a new case. Usually the pockets are deep enough they just aren't “square” in the corners or of a uniform depth. This step and the flash hole deburring would have been done after fireforming.

Tom

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CB posted this 05 July 2009

Dan

I agree with you on primer pocket cleaning. Most skip this this step because of the time involved and they see no value in the step. Mostly because they are lazy. Not saying that I clean primer pockets all the time but I do most of the time. What I am always looking for is seating my primers below level with the primer pocket. If I notice the my primers are hard to seat and I can feel they are not in the way I want them I stop and clean primers pockets. I have several types of tools for this, the one I use for small primers is a Sinclair but the old Lee ones work fine.

Stephen Perry

Angeles BR:fire

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hunterspistol posted this 05 July 2009

     I shoot new brass, then when it's once-fired, go to cleaning.  I like the RCBS (any brand works) brush with two brushes and a handle. Just doesn't cut brass, it's steel brushes that are real stiff. That works for me, I can't understand why you'd leave the crud in the primer pockets.  I work brass, primer pockets, case mouth chamfers and all. I have something in my hands, the coffee is good, and the radio keeps it moving. 

     Only been doing this about 5 years and still learning but, there are details not to be left out.  Unless, of course, you like paying for new brass!

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JetMech posted this 06 July 2009

A picture tells a thousand words, Dan. Maybe it's old-school thought, because I was taught from the beginning to clean the pockets. I've read more than a few times lately that it's a waste of time because the writer sees no difference in accuracy. Well, if you have 1.5MOA rifle, you probably won't see a statistical advantage, but, as you stated, it's easier on the tooling, you know the primers are seated correctly, and maybe, just maybe, the ocassional flyer will be eliminated. Plus it helps my confidence factor, knowing I've done everything I can do to produce the best possible round.

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corerf posted this 06 July 2009

Hello folks, back after a 2 week vacation. Absolutely clean primer pockets and uniform them with a tool. I use the Lyman kit, it's not the best and was designed more for mil brass pocket cleanup but it sure squares the bottom of the pockets and they go in easy. I do it to all rounds loaded sans a few 38 sp's for friends who can't conceive the difference. I de-burr flash hole as well, trim OAL, de-burr mouth in and out and outside turn for concentricity. My Savage shot a 5 round .192 group with this prep in wind on a rainy day from a bench. I believe I could have unloaded 5 rounds of factory Remington ammo, prepped the cases same way, reloaded and gotten a 50% improvement in factory groups due to prep. It pays, and like hunterspistol says, the coffee is good!

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CB posted this 12 July 2009

core rf

We need to be realistic about cleaning primer pockets. Milling primer pockets will not give a 50% gain in accuracy of factory re-assembled ammo. Cleaning primer pockets does nothing more than remove residue of spent primers in a primer pocket. Also I see no proof that clean primer pockets contribute to better accuracy. I shoot NBRSA BR and know of many who mill primer pockets but skip the cleaning process. Not saying they don't clean pockets at home but not while competing. Continual cleaning of primer pockets risks loosening them up, that's why lot's of BR shooters leave them dirty. As far as cleaning primer pockets tapping the case on a bench will remove all the loose pieces and dust. The rest left in will not affect your primer seating. The idea is  be careful to not take a chance of loosening up primer pockets with a primer pocket tool. After saying all this I do clean primer pockets for rifle cases but only when I feel my primers are not seating properly.

Stephen Perry

Angeles BR:fire

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corerf posted this 12 July 2009

If consistency is what creates tight groups, then consistency in primer pocket prep is as key as properly measured powder charges. If primers just go bang and the left over primer residue in reality make little or no diff., then why would anyone use bench rest primer?? Certainly the minor improvement of pressure consistency would be as unimportant as the residue that prevents the proper depth of primer seat to be had. Why trim the case .003 OAL if the .003 depth idiosyncrasy in primer pocket that you will likely have, shot to shot doesn't make a difference. I assume all the guys with race guns that set world records probably just knock the crap out of the pockets as you suggest, just because it's not important.

Also ,please quote an individual as was spoken (or typed), do not state things that are not claimed.

I did NOT say this: “Milling primer pockets will not give a 50% gain in accuracy of factory re-assembled ammo."

To quote myself “I de-burr flash hole as well, trim OAL, de-burr mouth in and out and outside turn for concentricity. My Savage shot a 5 round .192 group with this prep in wind on a rainy day from a bench. I believe I could have unloaded 5 rounds of factory Remington ammo, prepped the cases same way, reloaded and gotten a 50% improvement in factory groups due to prep".

I have specified that I can take a factory case and do a full prep on it, not just clean the PP, and get a 50% increase in performance. Please be advised, the prep is substantial, not just one step.

I have yet to throw 16gr's of 4227 thru my 8 inch 357, thats a stout max load, behind 158G JHP's and have a pocket loosen, after 10 reloads. I clean them all each reload (pp's I mean), ream them once (first reload). Trim every reload for OAL. I also get groups that I have spec'd on this forum that exceed the average or very good handgun, by a long shot, under any conditions.

Additionally, the tools that every BR shooter uses to compete, like the flash hole deburrer is probably insignificant and doesn't improve my groups either. I mean, it's just a hole that fire comes out of, right?? Why should it be unshrouded for top performance on a full case of slow burning powder?? The burrs certainly can't make a difference, right??

Accurate shooting is 95% prep (physical and mental) and 5% you squeeze the trigger. Why is this forum discussing the finite mad science of melted lead, lube, application methods, crisco shortening, etc if minor prep changes don't make a diference?????

HMM?? Am I chatting in the wrong forum??

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CB posted this 12 July 2009

core rf

I'll pass on responding to your last Post. I said everything I wanted to on primer pocket cleaning to say in my 2 Posts.

Stephen Perry

Angeles BR:fire

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303PV posted this 13 July 2009

Another reason for cleaning primer pockets is that the residue is abrasive. I just don't want it to end up in the press mechanism . I deprime the cases with a separate press.

 

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CB posted this 13 July 2009

303

That is a good point using a seperate tool to keep primer residue out the press. I use a Jones decap tool for that purpose.

 

Stephen Perry

Angeles BR:fire

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303PV posted this 13 July 2009

I bought a Lee C press for $ 9  a couple of years ago. A decapping die is permanently installed in it. Ultrasonic cleaning is very effective in getting the crud out.

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