Does cleaning brass primer pockets matter? 

I am so thankful to guys like you for sharing this knowledge. Many of us don't have a budget for this kind of testing. This helps me focus my dollars on the things that will matter more.

In my testing primers do not seat as consistently(depth) when the pockets are dirty. If there is material in the pocket then there's only two options when you seat a new primer. The dirt either prevents the primer cup from firmly seating against the base of the pocket or it gets pushed into the cup itself. Neither situation seems ideal for consistency. I wet tumble my brass in stainless media after annealing so the pockets are cleaned without an extra step. So if you believe that consistent primer seating depth is important then cleaning pockets is something you should do. There may be too much noise in most shooting systems to resolve this difference though.

I really appreciate that you cover so many of the topics that come up in comments/chat. It helps me as I am a wannabe long range shooter. Like others my OCD would not be able to not clean, but love the info and on another note. Your content helps me decide what I need now and what can be down the road..

If you want to shoot at an elephant, you don't need to clean primer pockets. If your a benchrest shooter, shooting in the very low ones/zeros. You clean the primer pockets. Besides! Who wants to put a precision instrument that measures primer pocket depths in 1/2 thousandths into a dirty hole?

Thank you Padom for the NF scope review, I’m gonna order one soon

If you have the time clean them otherwise don’t worry about it. . A little scrapping of the bottom of the pocket with suitable tool might be worth it though. Appreciate your efforts to bring us informative videos John 👍. Cheers 🍻🍻.

Another great informative video 👍 Found the same results on numerous tests. As with everyone I'm looking to get the most accurate consistent load possible. In my case I'm running a 20in .223 DMR gas gun in 600yd F/TR so I need all the help I can get. This will be my 3rd year of competition and handloading and it should be a good year for me, gun shoots .5 avg, if I'm really on it'll shoot .2s and .3s. My downfall is reading conditions. My goal this year is to podium in close to half my matches. The gun and load will finally be the same for each match. Can't blame the gun or load on a bad day, just me and reading conditions. Love your channel, keep up the great work!! 👍👍

The question is; does enlarging the flash hole in Lapua brass matter? That's what I've been doing to mine. I kept forgetting to change to a smaller decapper and just got fed up. I haven't really noticed any negative affects. But then again, I'm not entering 1000 yard competitions.

Cortina mentioned in one of his recent discussions that he does not clean his brass - only brushes the necks out. I'm sure if it works at that level it will work just fine for the majority of us. I've seen folks grind at the primer pockets with one of those cheap cleaners and you can see the flakes of brass coming out of there... your primer pockets will likely be the first point of failure of your brass to begin with - there is no need to speed it up by enlarging them.

I wet tumble with stainless pins and the brass can still get some black bits in the primer pocket. The secret? Dump all your brass into the tumbling container and soak it with detergent for a day or two then tumble. Using warm water is even better.

Wow! Great video. Thanks John.

Tell Padom congrats on the scope choice. Glad they are happy.

Thanks for all the info, I am just starting out , and this answers all the questions !

Very interesting FCJ 👍🏻 Great video.

I've never cleaned my 9mm pockets and haven't had any issues ever. I wet tumble, no Steel Media and no issues for me.

Great shooting John,I wonder if there would be a difference after 5 reloading's without cleaning the pockets?

Great video, Thanks for sharing

Great test thanks John on the wash up you had the loads dater mixed up 56g was not 2900fps it was 57g 🤯 only a small mistake great test 👏👏👏👍

Seems like an amazing group, using single point of aim. Seems like good idea for match?

8:01 Hey, John. Your payment was received.

300 yard groups , wow. And that's why you do so well in F-Class. And those are just powder test groups ... Nice!

Your ES spread sheets at the end of the video don't seem to match the higher and lower speeds on the target. It also doesn't make sense your speeds lower with more powder. The ES seems to be wrong on your middle spread sheet, I get 19.6 dirty and 23.9 clean.

A nice clean , uniformed primer pocket helps primer seating precision . You can then feel the primer skirt bedding down on the pocket base each time . Even for hunting ammo I uniform the primer pocket , uniform and debur the flash hole but don't sort case weight or volume for average range hunting .

I don't really clean my bolt gun brass at all, the bulk AR and pistol is all lubed, sized/deprimed on the RCBS then wet tumbled so it's nice and clean before it hits the dillon.

John I noticed a few smiling faces or ejector marks. Do you consider that to be pressure that will negatively affect the life span of the brass? Thank you for what you do!!!

I think that there is a lot of speculation as to what suits best. Do you have the opinion of other shooters when it comes to, for example, primer pocket cleanliness vs internal case cleanliness?

Wet tumble! Best change I ever made, without a doubt!

I don't clean the inside of necks. But, wipe off outside of brass to prevent scratching die during sizing. Always clean primer pockets. With a primer pocket reamer. Sinclair/PMA. 6PPC. Different games. Different things.

It may not matter on target, but I will clean mine every time anyway. It just makes me feel (mentally) better about the job/process of reloading. Just like wiping my butt after sitting the throne makes me feel (both mentally as well as physically) a whole lot better than if I didn't.

one less reloading step for me, thanks John

Thank you John. One more step ELIMINATED.

Done both on 223 brass can’t tell any difference.

Would repeated firings without cleaning keep decreasing the pocket depth by that 0.010" per firing?

Great representation of the two extremes. What tool are you using to uniform the pockets?

Are you using metric I have never heard of 12-8 in imperial however I do know .128 as a prototype aerospace machinist for over 20 years. It can't be 12-8 mm

It was suggested that clean promer poxkets meant less carbon going down rhe barrel....thus ..better for barrel. Hiwever... any real world difference would be hard to detect..im aure. None the less i sonic clean..so..primer pockets are clean...one less variable...even thoug it seems irrelevant.

Do you clean up the flash hole

When you use lapua brass you do not have to work on your primer pocket, think that how consistent the dept from the primer is and how deep, more affects has.

And the winner is... 57grains! What powder? I assume that the cartridge is 7PRCW. Magnum or regular primers?

I noticed that the primer pocket depth is measurably different between the clean and dirty pocket. I try to maintain .008 recess on my primer depth. Some test I have seen say that that measurement makes a difference. Thoughts?

What brand turret magnifier is that?

Great information Sir. Tell me about the tool you used to measure the primer pocket. And Thank You.😎

Lapua = good to go out of the box. Greg at Primal stated this…

Statistics, again. You cannot compare extreme MV spreads from two shot strings without jumping through some hoops. ES is a random variable dependent on the size of the sample and the underlying variability in MV. Comparing the raw ES from one sample with an ES from another sample has no performance meaning. Might help you feel better (or worse) but that’s in your mind. A single ES from a single sample is a essentially a sample of size n = 1 of a random variable, the sample range. To gain insight from extreme spreads, you must generate repeated samples from which extreme spreads are accumulated. Shooters seem to treat ES as if there were true ES for a load. No. ES needs to be characterized by its properties, e.g., a load’s mean ES for n = 10 (for n = 5, mean ES will be different), median ES for n = 15, 95th percentile for n = 20, and so on. If you insist on comparing extreme spreads, several authors (e.g., Gammon, Bookstaber) have generated tables of lower and upper confidence bounds using Monte Carlo simulation. In your first set of velocities, the observed dirty ES of 13.1 fps has 90% confidence bounds (7.9, 19.0) fps; the clean ES of 20.7 (I could not get the 20.5 fps shown in the video) has 90% confidence bounds of (12.5, 30.1) fps. Since the ranges overlap, you cannot conclude the extreme spreads are significantly different. Better Path. Under the usual assumptions, you can test intrinsic characteristics of the MV variability by testing the difference between sample means and sample variances. Whether the sample means are from normal distributions with equal means is commonly tested with the t-test. For your first pair of strings, the null hypothesis (samples come from distributions with equal means) cannot be rejected at 5% significance (p = 0.2062). You can test if the data are from normal distributions with the same variance with the F-test. For your first pair, the null hypothesis cannot be rejected at 5% significance (p = 0.0929). Testing the sample averages and variance is far more powerful and informative than comparing two nearly meaningless velocity ranges. Despite arriving at the same conclusion for the first set, using some simple statistical tests provides a solid basis for conclusions rather than just good luck.

Quick question John does a dirty barrel make you have bad SD and ES

So... I keep doing what I was doing 😂

Hello John, on a resent video you were back at house before Swn with a gentleman that makes f class stocks could you please give me his name as I cannot hear it off film . Thank you .luvs your youtube a great help

I started using shooting bot, then it stopped sending alerts.

What tool are you using to measure the depths?

The sound of firing was much too loud on the video.

I stopped cleaning them awhile back, have noticed no difference. If anything I have been shooting better but that is probably related to other changes.

Why is velocity decreasing with increasing powder charge?

Nice comparison. 👍 Do you think barrel temperature had any effect in your 20 shot groups?

I played with that many years ago, couldn't see a difference that mattered as far as I could tell., that was with 1 case at 300+ shots, and a batch of 50 at 300+ shots over the course of a week each in my 32-40. I clean them if I'm in the mood these days. Pockets were not uniformed, bullets were breech seated, powder was out of a thrower on the bench for both setups. Gun shot 3/4MOA with 208gr cast bullets @ 1450fps.

Please tell me I dont have to lol 😂

What kind of shooting glasses do you use, they look like they have a split lens, great test, thanks for the info

Great video. Efforts like this keep advancing reloading a little bit each time.