Talk to me about flattened primers?

P

Prof Young

New member
Loaders:
Was loading some 223 today. Had to ream a lot of primer pockets. Noticed on some of the loads that the primer, while well seated, seemed to be a touch flattened out. I've seen that before on my 223 and never gave it much thought. They've always shot okay. Have I just been lucky in that regard? Is there a danger here?

Life is good.

Prof Young
 
The post is lacking all the information necessary to give a good answer.

Instead of giving you a fish,I will attempt to teach you some about fishing.

Read your load manuals.The stuff about process and pressures and "reading signs"

Follow the recommended load recipes and processes. Use publishd,tested loads..
Observe starting and maximum loads. Don't substitute components

Doing those things will go a long way toward staying within safe pressures.

"Reading primers" will not. Go ahead,look at them.I do. But don't jump to conclusions.

Use the "Search Function" here at TFL. Reew all that has been written on "reading primers"

You say this load has been shooting fine.

OK<review all the things I suggested you review,

Begin by listing for us EVERYTHING about the load,

And isoate the variable.

Give us a clear list of exactly what factors have changed before you saw "primer sign" leading up to "primer sign"

Then I'll share idas.
 
picture(s) and identify whos primer and what flavor. Some primers are 'softer' than others.

And FWIW, HiBC is right... read up and also provide us more to go on.
 
Noticed on some of the loads that the primer, while well seated, seemed to be a touch flattened out.
Click to expand...

Are we talking about live primers you have seated, or fired ones in the cases?

"flattened out" might, or might not have some meaning. Because there is "flattened" and then there is "FLATTENED!"

I've been "reading" primers for over half a century, and its not like reading tea leaves, nor is it pure bunk. Some of what people think they get from reading primers is bunk, some, isn't.

How, and how much the primer is flattened does tell you something. It doesn't tell you the exact pressure, or if it is in safe limits or not. I just tells you the pressure is abnormal for the system and components used.

WHY the pressure is different can't be told from the primers, only that it is different than what we expect to see.

Primers can be slightly flattened, which might be normal. They can be "flattened" to the point where the primer cup metal "flows" all the way to the edge of the primer pocket. This is not normal, and indicates higher then desired pressure. But it doesn't tell you how high the pressure was.

I've seen primers where the firing pin strike was almost flattened back out smooth. THis is way too much pressure, but again, no idea what the actual amount (number value in psi) is.

Primers can also be slightly "flattened" when seated, sometimes, and, if this is not noticed until after firing, can lead to false conclusions.

IF the fired primer doesn't look like you expect it to look, it tells you something unexpected is going on. What, and how much, and whether or not its a risk is up to you to figure out.

Good Luck!
 
All primers of a given size won't flatten out to the same appearance for a given pressure.

The fired cases of 7.62 NATO proof loads producing about 82,000 psi I've given folks to judge their primer appearance most often got the "looks okay to me" types of responses. Other comments were to the effect of being a little warm or high pressure wise but OK.
 
Well Professor, I will give you a direct answer, hopefully without insulting you! Yes, I have twice experienced crimped primer pockets that made proper seating difficult. Pretty common in 223/5.56. There are other tools, but I use a little gizmo sold by Speer that forces a tapered mandrel into the primer pocket. Works like a charm. Second instance was with some once fired 30-06 cases that I got for a really good price (Ha!). Other than introducing me to small base sizing, many of these were also difficult to prime. In this case, I'm just going to write it off and scrap the brass.

Problems that this can create are high primers that sneak past your inspection and, in a worst case, setting off a primer during seating due to excessive pressure. I have been guilty of the first. Never popped a primer, but I have heard of it. One reason we wear eye protection. Get you one of those primer pocket swagers and quit abusing those poor primers.
 
To expand a bit on what I said earlier, you can 'flatten" primers when seating them, something that may happen more with GI brass than commercial, due to the "tight" primer pockets, not just the crimp.

Depending on the exact adjustment of your press/priming tool, and variances in brass (between brands, mil vs commercial etc) you can have a situation where the primer is seated to the bottom of the pocket, and the seating tool still has some "push" left in it, and that small amount of "overtravel" can flatten the primer. USUALLY not a problem other than its appearance.

some years ago, I went from the press mounted to a hand held priming tool, and I found that despite the "clumsiness" and extra work, you could really FEEL when the primer was properly fully seated. And how the primer could be fully seated and still have more pressure possibly applied to it.

Doesn't matter for a lot of things the press/bench tool seating systems work well enough, its just enlightening to feel the difference.
 
Lot more to this than I realized . . .

Thanks for all the info and ideas etc.

As always there is a lot more to this then I realized.

Take and post some pics and we'll go from there.

Life is good.

Prof Young
 
My take is the poster is clearly talking about seating the primer, not a flat primer after firing. And it seems he is also swaging the pocket when he states he had to "ream" a lot of pockets.

I have experienced exactly the same thing with seating .223 primers, even after swaging those that need it and I have never had a problem with a primer going off on me or failing to fire. As stated by 44AMP, it's just an appearance problem.
 
This is a real struggle point for me....primer flattening is a pressure sign. The trouble is there are just too many drawbacks to make it absolute.

Still, if I have flattened primers, I stop and reassess my loads.

Essentially, I view primers that are not excessively flattened as a good sign, but not an absolute sign that loads are safe. If primers are flattened excessively, I view that as a bad sign.

This is because of how primer flatten. When the cartridge fires, the primer comes out of the case. Then the case stretches back onto the primer. The force of these 2 actions determines how flat the primer gets. Well, the biggest factor is pressure, but it is not the only factor. The other thing is straight wall cartridges ....they don’t really flatten the same.

You should look into case pressure ring measurement.
 
First,I'll agree that its quite possible the OP meant that his process of removing primer crimps isn't qute perfect,and the primers are being deformd by the primer punch during high effort priming.

I may have misinterpreted the post as I associated "primer flattening" as a voodoo "pressure sign"

If that is the case, I suggest re-evaluating the process of reaming or swaging the pockets to remove the crimp.

Some processes are better than others. Our subject may have just a few cases or two five gallon buckets of military once fired to process.
A hand held Lyman VLD case neck chamfering tool can work for a few.

If its part of the routine of processing brass,the bench mounted Dillon pocket swage is a good tool. A Dillon 1050 press can be set up to do t during the loading cycle.

It depends n the quality of reload you want to make,but some folks just shrug and crush them in.For some folks,if it goes bang and loads the next round its good enough. Watch out for high primers and expect velocity variation.

I prefer Dillon swaged proper pockets.

as I said before,I look at my fired primers,they MAY give me some sort of clue about something,but they are not a pressure gauge.They are not a red,yellow,or green light. (OK,They CAN be a red light) They are good for a hunch.
 
I've noticed primers backed out past flush with 308 Win case heads when powder charge is more than 10% below max. .005" with regular brass cases. .007" with nickel plated cases. Fired case headspace is near an equal amount less than before firing. Case shoulder gets set back from firing pin impact and case doesn't expand to chamber limits.
 
Let me have second pass here . . . and thanks.

Okay Loaders:

See pic below before going on.

Primer on left is "flattened." Primer on right is "high" and I can't get it to seat even with lots of pressure. I've been loading the brass with the flattened primers and they shoot just fine. The high primer brass go into the reject/redo box.

Behind/above the primers is my pocket reamer. I put it in the chuck of a cordless drill and have at it. I think it's a Lee reamer.

This (flattened or high primer) only happens when I load 223, and 223 are the only brass I load that I need to ream pockets on. I'm guessing the flattened primers are in the brass that needed reaming and the reaming was not a complete success.

I'm using a Lee turret loader that seats the primer on the down stroke. I can definitely tell when a primer is well seated save for the flattened ones and the high ones. On those I can usually feel that something is amiss.

Okay I think that's the whole story.

Talk to me and thanks in advance. I learn a lot from all who frequent this forum.

Life is good.
Prof Young
 

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Aha! We are on the subject of primer flattening upon primer insertion, not post-firing.

I agree that during my career of handloading 17 different calibers has only encountered a problem with primer insertion in the .223/5.56 cases, which is eliminated after a pain-in-the-ass swaging with a RCBS tool, designed for that purpose. But once and done.
 
Depth?

Loaders:

I don't understand how depth can be the problem. The primer pocket had a fully seated primer previously. How could the depth become less?

I think the problem is with the primer pockets that have a crimp. If they are not "un-crimped" enough it takes a lot of force to get them in. But then again I may not know what I'm talking about.

I thought the OP made it clear that I was talking about the reloading process.

Thanks again to all and . . . talk to me.


Life is good.
Prof Young
 
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