what causes bad primers?

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I didn't want to admit this to anyone when I did it, but I had 12 primed 38spls that I mixed in with my dirty .357mags by accident and ran them through the ultra sonic cleaner for 16 minutes with citric acid and Dawn detergent.

When I discovered this I set them up on a shelf out of curiosity and left them dry for a month and they all fired. I couldn't tell a difference between them and new primers ... The things are tough!
Yes and thanks for sharing. :thumbup:
 
BTW, do you have a hand primer?

Maybe you can hand prime a batch of 50-100 and make sure they are .004"-.008" below flush or as deep as you can seat them to see if you experience any more issue?
 
It is possible you seated them to hard and broke the primer pellet.

I am quite certain this has happened to me. Primers that did not fire, given multiple tries in a rifle, I took the primer out, placed it on a range top burner. I placed an upside down cast iron frying pan above the primer, to keep things from flying about. Once the burner got hot enough, the primer went bang. Conclusion, there was enough primer cake to make a bang. Most probable cause of the misfire: cracked primer cake between the anvil and cup.

this article is well worth reading, and also for the understanding of setting the bridge thickness.

Mysteries And Misconceptions Of The All-Important Primer

http://www.shootingtimes.com/2011/01/04/ammunition_st_mamotaip_200909/

Page 5 of 9


The real story is that Boxer primers leave the factory with the anvil higher than it would be when seated in a cartridge case. Seating so anvil legs touch the bottom of the pocket lets the anvil tip penetrate into the pellet of mix. The nearly universal recommendation of having the primer cup bottom 0.003 to 0.005 inch below flush with the case head exists to set the proper amount of priming mix between the cup and the anvil tip.

This critical distance is known as the bridge thickness. Establishing the optimum thickness through proper seating means the primer meets sensitivity specifications but does not create chemical instability. However, failing to set the bridge thickness through proper seating depth is the number one cause of primer failures to fire. The bridge thickness is too great with a high primer, even one whose anvil legs touch the bottom of the pocket
 
Most probable cause of the misfire: cracked primer cake between the anvil and cup.
Like cap guns, I believe priming compound inside cups are powder and not solid - http://www.hho4free.com/black_powder/primer_powder.html

When I disassembled primers for the Tula SP primer thread, I noticed once the barrier was removed, the priming compounds were powdered and not solid (I think they are powder compressed into somewhat solid state held by moisture barrier/sealant) - https://www.thehighroad.org/index.p...ts-your-experience.630512/page-2#post-7794378

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Notice Tula and PMC primers with barriers removed showing powdery priming compound. Winchester/Magtech primers still have their barriers/sealants intact.

index.php
 
Sometimes you can do everything perfectly & if someone else messes with your stuff or a mfg
screws up then you feel like it is your fault & there is no way to prove it otherwise.
If the rest of them fired ok then it is probably not your fault.
I bought a huge load of reload eq from a fellow years ago & NOT to my knowledge the eq was
hauled here in the back of a pick up truck while it was raining.
When I found out, it was only by noticing one primer box had a slight water line on it.
If I had not seen that, there would have been lots of failed primers.
I had to properly dispose of thousands small rifle primers, knowing lots were probably good
but who would load with them?
 
Like cap guns, I believe priming compound inside cups are powder and not solid - http://www.hho4free.com/black_powder/primer_powder.html

When I disassembled primers for the Tula SP primer thread, I noticed once the barrier was removed, the priming compounds were powdered and not solid - https://www.thehighroad.org/index.p...ts-your-experience.630512/page-2#post-7794378

index.php


Notice Tula and PMC primers with barriers removed showing powdery priming compound. Winchester/Magtech primers still have their barriers/sealants intact.

index.php

I love your primer posts! :p You have done a great job informing us on your tests.
 
I'm going To pull these failed rounds and look at the primers under magnification. I'll post photos so you all can chime in but assuming the anvil is present what else should I look for to verify the primer being good/bad?

I just must assume the fault is somehow my own but I really want to know what exactly I did. Dawn residue on the cases maybe? That's the only contaminant I feel confident may have touched the primers so I'm hoping to find a visually confirmable mechanical defect, either manufacturer related or user induced.

Can I tell if I cracked or over seated from looking once I deprime?
 
I'm going To pull these failed rounds and look at the primers under magnification. I'll post photos so you all can chime in but assuming the anvil is present what else should I look for to verify the primer being good/bad?
Before you do anything, I would suggest you try these first:
  • Prime "control" test cases with known clean/dry primer pockets with primers (checked for presence of anvils) seated to -.004" to -.006" below flush (or with definite 1st/2nd resistance force felt by hand priming)
  • Pull the bullet/powder from rounds that did not fire
  • Shine a flashlight through flash hole to check for presence of an anvil
  • If anvil is present, I would chamber the primed case in the GP100, point in safe direction wearing hearing protection and fire
  • If primer doesn't fire, try again
  • If primer fires on 2nd or 3rd strike, cause was anvil tip was not pre-set against the priming compound
If primer still doesn't fire but all the "control" primed cases did, problem is not from the primers and I would then look at primer seating procedure, possible sources of contamination and hammer spring.
 
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