Is it really necessary to clean the primer pocket everytime?

[hounddawg]

That's what I do and use - some people are articulate in life, some people are half-ass. I was taught that if something is worth doing, it's worth doing right or not at all.

if it works why fix it. some 100 yard 5 shot groups using unpolished brass and dirty primer pockets. Would polished brass and a clean primer pocket gave me .100 group instead of .192 ?

[Unclenick]

There is a perfectly lovely can of worms opened up here.

Do you need to clean primer pockets? I think it depends on what you are shooting and other objectives. Dillon suggests cleaning them if you start getting high primers. Some claim to have had this problem and some never see it. I don't recall running into it with .45 ACP, and with target loads I've taken a number of those to the 50 reloads mark in the past loading on a Dillon progressive. Dillon claims to have tested the effect of uncleaned primer pockets on accuracy and found none. That doesn't guarantee a benchrest shooter won't see a difference, but then, he won't be loading on a progressive press. I certainly can't tell any difference in handgun load precision.

On the other hand, there are a couple of arguments for primer pocket cleaning. For high precision high power shooting, cleaning with a primer pocket depth uniforming cutting tool can help improve primer position consistency. The web between the bottom of the primer pocket and the inside of the case is expanded into the primer pocket slightly by pressure. When you clean the bottom of the pocket with the tool, it also cuts the flowed brass back to its previous depth. The cleaning itself is not the objective here, but rather the byproduct of removing excess brass is. So ti's debatable whether this should even be called cleaning, but those doing it seem to.

A different argument in favor of primer pocket cleaning has been presented by a former Aberdeen Proving Grounds test director. He suggests, from his experiments, that age-hardened carbon particles blowing down a high power rifle bore make a significant contribution to bore and throat wear. He thinks it may be the difference between barrels that shoot out at 3,000-4,000 rounds and barrels made from identical steel running 15,000 rounds when carbon is kept soft (by heat, as in full-auto bursts). I don't know that his theory is correct. I haven't seen any wear issues in the .45 ACP barrels that I have been shooting with dirty primer pockets, but then they operate at much lower temperatures and pressures than a high power rifle does. I have shot out high power rifle barrels, all in the sub-4,000 round range, but I've also taken note of reports of some M24 5R barrels going over 15,000 rounds without losing accuracy. Military snipers keep these barrels clean and always fire new cases without old carbon in them. So there could well be something to this.

The fellow with the carbon theory suggests you take a box of new ammo to the range along with a decapping tool and a primer pocket scraper, then fire the box and decap and clean half the cases right there at the range before you pack up and leave. Clean the other half a day later and he says you will be surprised how much easier cleaning is at the range. This is due to the carbon age-hardening. It's not normally convenient to decap and clean at the range, so he has gone to the stainless steel pin cleaning approach.

What about over-cleaning? A member at the CMP forums recently commented that if he gets a high polish inside the necks of his cases, his muzzle velocities see higher standard deviations and extreme spreads. The polished neck interior could have increased surface friction with the bullet due to higher contact effectiveness. That would increase start pressure, which would be good if it was consistent, but in that member's experience, it isn't, perhaps due to irregularity of dust or other contaminates or the level of the polishing itself. So, he thinks you need to avoid over-polishing. Someone else suggested you'll have to add a dry lube inside the neck to prevent the tight connection if you do insist on a high polish.

I've noticed before that highly polished cases are harder to find in the grass. They reflect the color of the grass and surroundings with more fidelity than a duller yellow case does, especially at the edges, making the contrast harder to discern. So it may be, from the standpoint of neck grip, carbon removal, and policing your brass in grass, a slightly dull chemically cleaned case is best best. But I'm not going to make that a blanket recommendation without some careful experimenting. It's just a possibility.

So, how carefully and how much should you clean any part of the case, primer pockets included? Well, as I said in the first paragraph, it depends. At least there is some fertile ground for experimentation here.

[Sevens]

You never cease to amaze me with your posts, Uncle Nick. There's always something more to consider.

It's been said in this thread already... regardless of what I do with primer pockets, I still believe that if it makes a handloader happy and it gives him more confidence in his loads, he absolutely should clean those pockets.

I'm thrilled that I don't do it anymore. I do... on occasion, with rifle rounds. I'll probably quit that also. I hardly load any rifle... but maybe one day that will change.

[hounddawg]

What about over-cleaning? A member at the CMP forums recently commented that if he gets a high polish inside the necks of his cases, his muzzle velocities see higher standard deviations and extreme spreads. The polished neck interior could have increased surface friction with the bullet due to higher contact effectiveness. That would increase start pressure, which would be good if it was consistent, but in that member's experience, it isn't, perhaps due to irregularity of dust or other contaminates or the level of the polishing itself. So, he thinks you need to avoid over-polishing. Someone else suggested you'll have to add a dry lube inside the neck to prevent the tight connection if you do insist on a high polish.

I can vouch for that. That is why a few posts back I recommend that those who want to use the steel pin method use a neck lube. I have found even on my non polished cases if I use a small paintbrush and dust the base of the bullets with some mica or even just plain old talc (baby powder) I get a much smaller SD on my velocities plus they smell minty fresh LOL.

Interesting info on the carbon/neck throat wear aspect however. I am still debating on whether to go the ultrasonic route. No way I will ever do the water and steel pin cleaning, way too much hassle just to get them shiny in my opinion. Each to their own though.

But as you said, each to their own.

[Unclenick]

I realized after posting, over-cleaning (polishing, really) is likely the reason I got lower SD's when I first started experimented with moly bullets. They supply the release coating. You do, however, need to burnish your case chamfer after trimming to keep it from scraping the moly off.

[federali]

I have found that primers tend to seat more easily and uniformly in clean pockets. As for increased accuracy--who cares? I don't measure my groups with a micrometer.

But, I have found that high primers will cause light hits in my S&W M&P and my Marlin 336 so it's important for me to insure that primers ar fully and properly seated. I went one step further, I bought a primer pocket uniformer which cleans the pocket and recuts it to proper SAAMI specs if necessary. After uniforming several hundred rounds of .45 ACP, I generated a small mountain of brass shavings and effortless and uniform primer seating. Oh, and yes, zero failures to fire.

[FrankenMauser]

Originally Posted by Unclenick

Dillon suggests cleaning them if you start getting high primers. Some claim to have had this problem and some never see it.

I didn't know that Dillon suggests cleaning primer pockets for high primers.

It's nice to know I'm not the only person that has seen it, though.

From page one:

Originally Posted by FrankenMauser

Don't bother cleaning primer pockets on handgun ammunition, unless you have 10+ reloads on the cases. At that point, it can be beneficial to clean the primer pockets, to regain about 0.005" (or more) of primer seating depth.

[TXGunNut]

I'll define "right", Mike. If I get it "right", it puts a smile in my ugly face. I have different goals and expectations for each rifle, cartridge and even individual components. Doing things "right" is a moving target but a worthy, often frustrating goal. Good points, all. There is always something more to do to get it "right". Some of them have actually worked for me.

[MOshooter65202]

I've been following this thread with interest and also stated that I clean the pockets everytime and tumble the brass twice in my brass prep,for me this is not just to make the brass shiny and pretty.
My reasoning for tumbling brass twice? The first tumble is to help keep my resizing dies cleaner then after resizing and cleaning the primer pockets I trim and chaffer my rifle brass only everytime for uniformity,after these steps I tumble again to help clean any lube residue or contaminants before priming,charging,and bullet seating.

This just works for me and the way I like to prep my brass,I don't knock others for their practices.

Here's a little food for thought
If you live in areas with high humidity and reload large quantities of ammo for stock for extended periods without cleaning the primer pockets,what's the chances of the residue left in the pocket possibly containing moisture and other contaminates that could effect primer performance?....Just wondering?

[Mike Irwin]

"what's the chances of the residue left in the pocket possibly containing moisture and other contaminates that could effect primer performance?....Just wondering?"

Nil.

The residue isn't hygroscopic, so it's going to contain the same amount of water as the brass.

As for keeping my dies clean....

I don't tumble, but I do wash my brass.

[homesick]

I clean primer pockets each and every time, it's part of my process and just wouldn't feel right if it weren't done. Does it have to be done NO should it be done YEP. Kinda like each to his own.

[wncchester]

"Is it really necessary to clean the primer pocket everytime?"

Not at all so far as the ammo goes. But it may make your front sight rust.

[Unclenick]

I'm wondering now if the brand of primer has some effect on how much residue accumulates? It would be a worthy study for someone to undertake.

[FrankenMauser]

I'm wondering now if the brand of primer has some effect on how much residue accumulates? It would be a worthy study for someone to undertake.

It's an interesting concept. I do seem to notice more residue with CCI primers, but I can't say that my observations have been fair and balanced.

[Unclenick]

I was using Federal 150's most of the time when I was still shooting bullseye matches with the .45, and that's were my multiple loads came from. Those primers have higher sensitivity than some, so the cushion probably didn't bother them as much. Also, a lot of dust came out of those cases with the decapped spent primers, so It probably took more effort to build as much residue up.

[Sevens]

I can tell you that when you resize/decap a round of S&B, almost no matter what caliber... it's as clean as a whistle. So whatever they are doing is what you are looking for.

[Unclenick]

That's what I'd call a good clue. I think their primers were listed for sale at one point, but don't know if anyone is importing them currently..

[TXGunNut]

I'm wondering now if the brand of primer has some effect on how much residue accumulates? It would be a worthy study for someone to undertake. -Unclenick


Haven't given it much thought but now that you mention it I do recall a difference in some 45ACP brass I scrounged awhile back. One brand, Top Brass, seemed to have very clean cases and primer pockets. Federal SP brass seemed very clean as well. Loading mostly rifles these days using Federal primers and they don't seem especially clean, just very consistant.
I'd be interested in the results of such a study, just don't think it would fit in with the loading projects I have scheduled. Also wondering if a visual inspection would suffice or if we'd have to determine the weight of the residue. Big question is, will a clean primer perform better than a dirty one?

[Unclenick]

I just located some S&B primers at Graf & Sons, if this project has any takers?

[hounddawg]

Interesting Uncle Nick. Just ordered powder from them last week, if I had known I would have had them throw in a box or 2 of primers and tested them on new cases. There is a Gunshow later this month though, I will check some of the powder/primer vendors there. On a side note I have a Lyman case care kit on my wishlist for the chamfering tools, it includes primer reamers and cleaners so I might start reaming my primer pockets on my rifle cases just for the heck of it.

[FrankenMauser]

I just located some S&B primers at Graf & Sons, if this project has any takers?

I'm considering it.
I just haven't figured out how to get empirical data for something like primer pocket residue. Weighing scrapings is trivial, but about all I can come up with for "hard" data.

Tracking primer seating depth could be valid, but I haven't figured out how to reliably measure it, with repeatability.

9mm Luger would be a good candidate for a handgun cartridge.
My 6mm could be a good choice for a rifle cartridge.

I'll have to see what else I have on hand in the various types. I'd like to compare as many brands as possible.
Edit: It looks like I was correct. Small Pistol and Large Rifle would be the best approaches, for me. But, I currently only have CCI, Winchester, and Federal primers in each of those types. I would have to pick up some Remington, at a minimum; and would like to include Magtech and Fiocchi. (Which I could do, now, with Small Rifle, but I don't own a small rifle cartridge...)

[Jimro]

Just an aside about the milspec M24's going 15,000 rounds between barrel changes. The accuracy standard for an M25 is 1 MOA for five shots, if the issue sniper can't do that then a senior sniper will try, and if that fails they try a rest (to eliminate things like optics or nut behind the trigger issues). So we aren't talking benchrest accuracy here.

The Marine Corps M40 series of sniper rifles uses aftermarket barrels with a traditional 6 groove rifling pattern, and the M40s are assembled by Marine Corps armorers at Quantico.

But both the M24 and M40 are fed the same diet of M118LR ammunition. There are very good records kept on M40 rifles, and I have yet to hear of an M40 lasting to 15,000 rounds, so I think the difference is the 5R rifling in the Remington barrel, not the use of virgin ammo.

Jimro

[Unclenick]

Jimro,

Do you know if the Army and Marine snipers are using the same cleaning and maintenance schedules?

Nick

[Jimro]

The Army cleaning schedule for an m24 is "after a range trip" in garrison, and "once a day" in combat. I would expect it would be the same in the USMC, but I don't know first hand.

Army and USMC use the same equipment to clean with as far as I know, although most snipers I know buy and use their own cleaning supplies. However all the USMC Snipers I know haven't mentioned any M40 barrels not lasting to 6-8000 rounds, which is about when you'd expect a normal 308 barrel to start going (with a 1 MOA accuracy standard).

On a side note, the M40 in good condition usually shoots a little tighter than an M24 in good condition. Not enough to matter if you were on the receiving end, but enough that our snipers notice.

Jimro

[TXGunNut]

I'm considering it.
I just haven't figured out how to get empirical data for something like primer pocket residue. Weighing scrapings is trivial, but about all I can come up with for "hard" data.-FrankenMauser


I think that's going to be the tough part. I think this could require lab conditions and equipment to collect meaningful data. With the equipment I have on hand the only possible method would be to weigh 20-30 new cases as a group, fire them without powder or projectile, decap and re-weigh. Collecting and weighing scrapings would most definitely exceed my skill, equipment (and patience) level.