Popping primers

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13 years 8 months ago #6757 by markthenewf
Popping primers was created by markthenewf
I bring my LAR8 to the gun shop and get them to clear the gun (bolt was jammed out of battery with empty case stuck in the chamber). When this was done, a primer falls out of the bolt carrier group. That particular day I shot about 15 remington white box and about 30 of my reloads. Two rounds were missing a primer (from what I recovered) and these were my reloads which used federal once-fired brass and CCI large rifle primers. This points towards hot loads pushing out the primers which jammed up the action. Note that I can't see any signs of overpressure on the primers in my other fired reloads.

But wait, there's more.....

All the reloads were 150 gr nosler green tips with charges either at the minimum or middle charge of Varget. I always use a medium taper crimp with a Lee factory crimp die. Since I was working up a load, all the charges were initially calibrated on a digital and manual scale so I absolutely know that the charges were not hot. I have also noted that the cases have a very distinctive ejector mark. It's deep enough such that I can actually feel it if I run my thumb over it. So here's my thought: is it possible that the ejector isn't compressing properly and slewing the round off a smidgen to one side. This would result in the base of the cartridge not being fully supported at the bolt face. Would a partially bearing back face of a cartridge result in a primer being able to back-out under less-than-max pressures?

I'd appreciate any input anyone might have. I am also going to contact RRA, nosler, and Hogden and see if they've got some idea of what's up. Either way, the rifle is going to go for a checkup to RRA as soon as I can get to it. I can only hope that it's a faulty ejector causing all my heartaches with this gun.

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13 years 8 months ago #6758 by Edge
Replied by Edge on topic Re:Popping primers
I would suspect that it is the Federal brass. It has a reputation for being soft.

Next time you seat some primers, take notice if they are going in really easy or if there is some resistance. If they are easy going in, then your brass probably needs replaced

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13 years 8 months ago #6810 by Maximus
Replied by Maximus on topic Re:Popping primers
Make sure the bullets are tightly crimped. If they push back into the case as they chamber they can do strange things for pressure as well as accuracy. :blink:

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13 years 8 months ago - 13 years 8 months ago #6814 by markthenewf
Replied by markthenewf on topic Re:Popping primers
Edge: The only difference I've noticed in primer seating is between the Lake City 30-06 (which I've removed the crimp from) and any other brass. Obviously the LC brass is a bit more stout and you can feel it when resizing and priming. I really can't "feel" any difference when priming using my RCBS hand-primer.

Maximus: I've heard conflicting info on this. Some say light crimp so as to not increase bullet holding tension in the case which would in turn increase the pressure. The other school of thought is like you say (and what I've originally read in my loading books) that a crimp is necessary to ensure the bullet isn't shifting around in the case during heavy recoil. This is the case for my 308 AR, so I've been using a moderate crimp.

What sucks is about 80% of my brass is Federal once-fired, which I've trimmed and primed. So I've got hundreds of it just sitting there and now I'm paranoid to use it!

In the meantime, the AR upper is going back to RRA. I've asked them to go over the bolt assembly and chamber in order to assure me that everything mechanical is in order.

I've also ordered some winchester white box 308 from Midway (on sale for $12.99 a box) so that I'll have some good utility brass to work with. I've also located a guy with some Lake City M118LR once fired (match grade out of marksman rifles not machine guns). I think I'm able to get up to 1000 cases through him. I'm hoping that these materials and perhaps a finessing of the bolt by RRA will cure my ARs ailments. Fingers, toes, and eyes crossed!
Last edit: 13 years 8 months ago by markthenewf.

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13 years 8 months ago #6835 by Maximus
Replied by Maximus on topic Re:Popping primers
Have you checked your case length? :unsure:

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13 years 8 months ago #6921 by markthenewf
Replied by markthenewf on topic Re:Popping primers

Maximus wrote: Have you checked your case length? :unsure:


Yup. I full length resize and trim all my brass. I don't have the exact value in front of me, but I'm pretty sure it's as listed as the trim-to length in my Speer reloading manual.

That being said, I suppose I should have done a before and after measurement of the cases just to see how much they were creeping up in size.

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13 years 8 months ago #6924 by BUILDING MY SASS
Replied by BUILDING MY SASS on topic Re:Popping primers
A friend brought this thread to my immediate attention....I haven't followed it because the is EDGE'S domain... as far as I am concerned...but common sense tells us and the laws of physics...that a TIGHTER CRIMP...is not the issue...do that and someone will have a bolt carrier coming out their ass.....As a new reloader somewhat I have not had this issue...I am so ANNAL about my brass it isn't even funny...Common sense would state that you have plenty of pressure and crimping the bullet tighter will only send more force backwards through the primer pocket...and your ass...I would go with Edge's advice on this..it may be the brass...but...SHUT UP EDGE..:laugh: .are you cleaning your primer pockets well enough...are they seated .001 to .002 below the face of the head....when I seat my primers...I make sure that they are "BELOW" the face and seated very tightly...if you are reaming you pockets out...you may be doing it to much...this will make them loose and well physics in play...what is going to give first...the bullet with a light crimp...or a loose primer pocket....
I really don't think it is the extractor...it should not have anything to do with popping primer pockets....and from what I read...it is your re-loads that are dong this....
You said that you have a boat load of shells all ready primed...go back and make sure that they are seated properly...use a HIGH POWERED magnifying glass or similar device...also take EDGE'S advice and double check your case lengths...this also can have an effect on all ....there are so many things that can offset shells..that it is almost scary when you think about it...I just don't want to see anyone get hurt....double check everything...is my opinion and follow the manual to a "T"....
Max...sorry don't mean to Pee in you cereal...but a Tighter Crimp in this case is the wrong answer...and I don't want to see someone get hurt...

here is how I prime my shells...it is just for a look...as I said...I am annal about it...
go to about 2:56 to see how I check the primer depth....


Sorry to jump in on this Edge...but MSH sent me the note but did not comment further....the post is all mine using common sense...
Don't mean to step on your toes......my friend....;)
BMS....

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13 years 8 months ago #6925 by BUILDING MY SASS
Replied by BUILDING MY SASS on topic Re:Popping primers

markthenewf wrote:

Maximus wrote: Have you checked your case length? :unsure:


Yup. I full length resize and trim all my brass. I don't have the exact value in front of me, but I'm pretty sure it's as listed as the trim-to length in my Speer reloading manual.

That being said, I suppose I should have done a before and after measurement of the cases just to see how much they were creeping up in size.


After resizing I always check the length...for the most part...before is going to be with in a .002 of factory...so it really is not needed before resizing...but after and while trimming is essential...and a must...one of the golden rules of re-loading...also be consistent..with every case...at least to .0001 if possible..
BMS

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13 years 8 months ago #6930 by Maximus
Replied by Maximus on topic Re:Popping primers

Maximus wrote: Make sure the bullets are tightly crimped. If they push back into the case as they chamber they can do strange things for pressure as well as accuracy. :blink:


Lee makes a "Factory Crimp" die to crimp just like the "Factory". I use this on all my loads and have yet to have one "come out of my ass". :ohmy:

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13 years 8 months ago #6947 by BUILDING MY SASS
Replied by BUILDING MY SASS on topic Re:Popping primers

Maximus wrote:

Maximus wrote: Make sure the bullets are tightly crimped. If they push back into the case as they chamber they can do strange things for pressure as well as accuracy. :blink:


Lee makes a "Factory Crimp" die to crimp just like the "Factory". I use this on all my loads and have yet to have one "come out of my ass". :ohmy:


I use the same die...and for all mine...well different dies...you know what I mean...and I am glad you haven't had one...come out your ass...but if he is popping primers...crimping is not the issue...the issue is the other end...if you crimp tighter on the bullet....and have a loose primer pocket...WHERE IS THE PRESSURE GOING TO GO...out the back....have you ever seen a shell that for the most part exploded in the chamber of a AR....AR-10 type to be exact....it sent the bolt and carrier out the back end....and ruined the rifle...I wasn't there...but I seen what was left of the gun...not pretty....:ohmy: :sick:

I wasn't hashing on you Max...just saying your solution was not the right one or to be tried...I don't want to see someone get hurt...I know you don't either...RIGHT....
I did offer my apologies if you read it right....
BMS

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