[Kellen]

Primers lead to some confusion (for me at least). First, the jargon varies to an unfortunate degree. Some refer to a “primer pocket” while others refer to a “flash hole.” I’ve even seen talk of the “shoulder” around the flash hole, which is not helpful. I normally think one’s the actual hole in the cartridge while the other refers to the cavity in the head/base. Then there is the action involved, with verbs used including “uniforming,” “reaming,” “cleaning,” “squaring,” and “deburring.” I think some actions must be for the hole and others for the cavity… or both? For example, maybe both the cavity and the hole get uniformed? Confusing. Then there are references to what the spent primer actually leaves behind, such as “residue,” “flakes,” “obstructions,” and “compounds”; I’ve even seen the phrase “crusties left behind.”

So in sum I think what you can do is “uniform primer pockets by reaming” and “debur flash holes,” but saying that might just show how wrong I am....

And at the end of the day, does all that focus on primers really matter? Does a focus on the primer make a significant difference to accuracy? I know that some shooters can get quite anal about reloading and basically claim that everything makes a critical difference (and if they’re competitive match shooters then so they should). For the rest of us, how important is a focus on the primer when it comes to reloading? Psychologically, maybe focusing on the primer helps a shooter to believe it makes an accuracy difference, but I question whether it objectively makes a significant difference.

Then there is the question regarding types of primers and their impacts on accuracy, and that’s another whole topic….

To compare to grades, I like to reload my cartridges to a grade of “A,” but I don’t get so obsessive that I strive for an “A+” if you get my drift. So that’s the bottom line question, is a focus on primers needed to reach the “A” grade, or are they really just an "A+" issue?

 

[blaster]

my $.02, the primer pocket is where the primer seats. the flash hole is the hole in the primer pocket where the flame from the fired primer travels to ignite the powder.

Primers lead to some confusion (for me at least). First, the jargon varies to an unfortunate degree. Some refer to a “primer pocket” while others refer to a “flash hole.” I’ve even seen talk of the “shoulder” around the flash hole, which is not helpful. I normally think one’s the actual hole in the cartridge while the other refers to the cavity in the head/base. Then there is the action involved, with verbs used including “uniforming,” “reaming,” “cleaning,” “squaring,” and “deburring.” I think some actions must be for the hole and others for the cavity… or both? For example, maybe both the cavity and the hole get uniformed? Confusing. Then there are references to what the spent primer actually leaves behind, such as “residue,” “flakes,” “obstructions,” and “compounds”; I’ve even seen the phrase “crusties left behind.”

So in sum I think what you can do is “uniform primer pockets by reaming” and “debur flash holes,” but saying that might just show how wrong I am....

And at the end of the day, does all that focus on primers really matter? Does a focus on the primer make a significant difference to accuracy? I know that some shooters can get quite anal about reloading and basically claim that everything makes a critical difference (and if they’re competitive match shooters then so they should). For the rest of us, how important is a focus on the primer when it comes to reloading? Psychologically, maybe focusing on the primer helps a shooter to believe it makes an accuracy difference, but I question whether it objectively makes a significant difference

the only operation I have ever done to a primer pocket is to swage or cut the crimp out of military brass. I'm not a match shooter so I'm not anal about reloading. I have never had any problems with my ammo regarding not going through all those primer pocket preparations. that being said, if I come across a case that has a really grungy or green primer pocket, I just throw it away.

 

[Big Dog]

The primer pocket and the flash hole are different parts of the case.
One problem I had once was in trying to reload some foreign surplus 8mm Mauser. The primer pockets were Boxer, but the flash holes were too small. The decapper pin broke trying to push through it. Only time I ever had that problem.

 

[Blackrock]

My Lyman manual has information about primer pockets and cleaning and removing the crimp either by swaging or cutting. I have tried deburring the flashhole but never noticed any benefit from doing it.

 

[BigEd63]

For crimped military brass I use a RCBS primer pocket swaging set up on my press.

For extreme long distance shooting I deburr the flash hole in a manner that creates a tiny uniform tapered opening on mouth of the flash hole inside the cartridge.
The purpose is to aid in a uniform burn pattern for the primer and a uniform burn rate for each cartridge shot to shot.

Probably not needed for your average shooter/reloader but for precision shooting 600yds+ definitely so.

I don't do it on most smaller cartridges but definitely for the magnum ones.

 

[Dutch]

First, you want to make sure there’s no obstruction. Brass that has been in the mud or dirt, or was cleaned in walnut or other dry media, may have an obstructed flash hole.

You don’t need to worry about much else until you get into long range shooting or are trying to shoot every bullet through the same hole.

 

[OneShotKill]

For a decade or two I was concerned about primers but now not at all. Loading hot rounds, rifle or handgun, you often see a call for magnum primers, others say definitely not. Some gurus show a lessor amount of powder if using magnum primers. I finally just decided to use magnum primers on everything and it works very well. Some companies I think Federal even claim that their primer fits all. The bottom line is you want a consistent burn to aid in consistent velocity, which make bullets hit closer together in a group. The goal of the hotter primer is to get the total burn quicker. That of course requires a hole big enough to do what it needs to do. If using mixed brass, I have even found some with a tiny flash hole, a 1/16th drill uniforms them. I even found that by using magnum primers in 38 special, I could use less powder, that was when I could get primers regular or magnum at the same cost.

Then some rounds may call for rifle primers in a handgun, 400 Corbon is one, they suggest small rifle primers. Personally, I have not seen any definitive testing to show a better burn by the premium powders. When you start with rifles that shoot .5 moa, maybe at longer ranges it would matter.

But to me, if you are going to make a 1,000 yard shot, the brass is going to be new or once fired, same lot, same lot of primers and powder and bullets from the same box, all powder charges weighed. And if it matters, you probably want to weigh each bullet to make sure they are consistent. Pretty easy really and you can load 20 rounds ever hour or so. LOL

Point is, I just want a clean primer pocket and unless it reused military brass I do nothing to the primer pocket. For a time, I used the little pocket reamer on all 30-06 cases, after a while I noticed a few loose primers. Not good, the more you mess with them, the quicker they get loose, so I just dumped that idea. There is only so much time...

A few muzzle loader guns have been designed to use 25 acp brass with small pistol primers because they work so well on black powder, even preferred to 209 primers, won't take the time to explain it here.

And then there are the brass shotgun shells. I reload the 410 for my Marlin 1895 lever action, anybody want to guess what primers you use in brass shotgun shells>>,,,, https://www.midwayusa.com/product/1657121283?pid=860921

 

[Moroco Mole]

I always clean the primer pocket with the little lee tool and look to see if there is an obstruction in the hole.
If military brass and crimped. I just take a drill bit and cut the crimp out of the end.
Plus If dealing with crimped pockets. I keep an extra rod around for the de-primer in case a crimp is really hard and I break the de-priming rod.
Use magnum primers for magnum loads. Rifle for rifle, ect. Stick to the same brand when repeating a load.
Other then that, do not worry too much.

 

[Mindy up North]

I keep the pockets clean and always make sure the flash hole is unobstructed after tumbling, that's pretty much it. Never had a problem with this basic level of prep. Every now and then I get some brass that could actually benefit from deburring - since I consider burrs an obstruction, but this has been rare for me.

 

[blaster]

since I don't do all the primer pocket prep., I tumble my brass before de-priming. that way I know the flash hole is clear.

 

[Rocky7]

So in sum I think what you can do is “uniform primer pockets by reaming” and “debur flash holes,” but saying that might just show how wrong I am....

I think that is correct.

I used to "uniform" primer pockets but, as OneShotKill said, it seemed to me I was getting loose primer pockets sooner than I used to so I quit that. I still debur primer pockets on new brass (done from the inside) but suspect that I may be wasting my time. I am a hunter, not a silhouette shooter. That said, I am prepared to do what I have to do to get to 0.5" groups. After that, I'm done.

And at the end of the day, does all that focus on primers really matter? Does a focus on the primer make a significant difference to accuracy?... So that’s the bottom line question, is a focus on primers needed to reach the “A” grade, or are they really just an "A+" issue?

Yes and no. The hardness of primers matters if you are shooting an M1A, for example. I think there is a consensus that a softer primer like Federal should not be used with a floating firing pin. I won't use Winchester primers on anything; might be just me but I've not had good luck with them.

I think it is important to stick with a brand and strength (ie, magnum or not) when loads are developed, whatever brand you use. Some people use magnum primers in everything and I believe that is fine if you stay with it. I doubt your firearm would blow up if you moved back to regular primers but I think you'd see a difference.

I don't know about you, but I am aware that I read too many gun magazine articles; which has sometimes caused me to fix things that aren't broken so I think it is very wise to question some of the nit-picky stuff we read. It might have been written by someone with nothing important to say. Jack O'Connor cautioned against dithering over the minutiae, too, and whatever he said has always been good enough for me....and proved true sooner or later.

 

[Junction15]

The largest portion of my reloading is handgun calibers. Several thousand per year (yeah I know, that ain't much but it's all I have time for).
I shoot mostly USPSA matches and 3 gun, so if I can keep my shots inside 4" at 25 yards, fast, I am a happy camper. My main concern with primers is that they feed reliably through my Dillon 550 priming system.
I have found Sellier & Bellot primers will sometime get upside down. Which I find AFTER the round has gone through the cycle. And I am very sure all primers went into the primer tubes correctly. But that is a primer dimension issue and not a primer pocket issue.
All other primer brands I have used work fine but I have not noticed any accuracy differences, nor ignition differences.

 

[ninwnc]

I tumble my brass before resizing. Make sure the cases are empty. Lube and deprime/resize. Tumble again. Then check each primer pocket and flash hole for media. I normally use the Lee primer pocket tool to give each one a quick scrape and check the flash hole for obstructions. I normally use Winchester primers. I have used some CCI primers when Winchester primers were nor available.

Most of my shooting is 200 yards or less, and that's good enough for me.

 

[Mowgli T.]

I don't do not care for any manifestation of the Lee tool. A small bladed screwdriver works very well. I decided that having the correct components trumps about anything else. Also, doing some heavy loading and groundhoging we came to a conclusion. That conclusion was that after the basics one gets to the point of diminishing returns fast in a factory chamber. My two personal favorite primers come from CCI and Winchester. Those two brands are also the most commonly seen in stores. Take care and be safe.