Numerous misfires?

pods8

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After reloading and shooting hundreds of rounds w/o a single misfire I've suddenly got a high occurrence of misfires while trying to help a friend develop a load. To date one of my pet loads (different brass and primer combo) hasn't misfired in his gun (likely a couple dozen rounds fired) so although I plan to pull apart his bolt and clean it out and dry lube it I don't feel that is the root cause.

[Note mag primers are being used as that is what was on hand, loads were worked with them in mind, lets not hash out that selection aspect other than its relevance to a misfire or not.]

My previous loads with WLRM's and both FC & RP brass haven't had a single hiccup in hundreds of rounds in my gun nor a couple dozen in his. He bought Hornady brass for his loads and I cracked into a box of 9.5Ms (again it was on hand, first time using them). We bagged a load ladder today as 3 out of 7 failed to failure to fire!

Additionally I had loaded up a small ladder .5gr increments with a new (to me) bullet to determine a max charge using those same 9.5Ms for my gun (first time using them) in some WIN brass, 1 of 8 failed to fire.

Primers were seated with a RCBS hand primer, I noted more resistance felt with the 9.5Ms vs WLRMs but nothing preventing a complete squeeze of the handle (I'm under the assumption the spring determines seating force in that tool but let me know if I'm unknowingly crushing them in doing what I'm doing, I'm doing the same thing I've always previously done w/o issue using the WLRMs).

Right now it seems the 9.5Ms are generally at the center of the issue (be it the actual primers, or the primer/brass combo, or how I'm seating them). Right now my plan was to break down all those rounds leftover (as the 9.5M combo is unreliable for whatever reason) and run out and grab a fresh box of primers, likely WLR or 210s if they are around.

If someone has a clue on what is going on here I'm open ears.
 

pods8

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Issue is across two guns that shoot my WLRM stuff fine so lower probability firing pin or headspace.

Just had a potential light bulb go off. These were bought in the winter while traveling and were in the car for a couple days, wonder if they attracted condesation during the times the car cooled and warmed? They were in the factory packaging only.
 

Laelkhunter

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You said they were harder to seat. Is it possible they were not completely seated in the primer pocket?
Did you try shooting them a second time, and if so what was the result??
If they fired on the second try, possibly they weren't seated completely, and the first strike of the firing pin seated them allowing the second strike to fire them??

If you look closely at the flat part of the primer when you take it out of the package, you might be able to see water marks (stains) from condensation if that occurred from the temp changes in the car.
 

just country

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morning, sounds like a primer issue. if at all possible use fed 210m. have shot hundreds of rounds, never had a failure.

just countrylightbulb
 

Rick Richard

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I had a failure yesterday using Federal 215. I think my failure was due to cleaning media (walnut shell) blocking the fire path from the primer. I failed to adequately clean the cases after tumbling. Just another thing to think about.
 

pods8

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Yeah a primer swap is the plan just wondering about the root cause (contaminated primers, that primer/brass combo, something I am doing, etc.).


I use a pilot trimmer after tumbling which knocks stuff out of the flash hole. It's possible but for the number of occurrences seems improbable.
 

pods8

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You may try and see if your pockets and primers meet these specs:

Ballistic Tools - Articles - Minimum and maximum primer and primer pocket dimensions
So I popped a couple misfired ones and some fired ones. Common thing with the misfires is the anvil legs were pushed flush with the cup rim which was 0.1200". The fired ones the legs were still a bit proud of the rim and measured 0.1280". Measuring a handful of fresh ones from the box the anvil legs were about 0.1360".

So am I crushing the anvils into the primer cups with the RCBS hand primer? Is the firing pin crushing the legs into the cup? Is the cup supposed to be 0.1230" minimum or just the legs?
 

cjuve

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So I popped a couple misfired ones and some fired ones. Common thing with the misfires is the anvil legs were pushed flush with the cup rim which was 0.1200". The fired ones the legs were still a bit proud of the rim and measured 0.1280". Measuring a handful of fresh ones from the box the anvil legs were about 0.1360".

So am I crushing the anvils into the primer cups with the RCBS hand primer? Is the firing pin crushing the legs into the cup? Is the cup supposed to be 0.1230" minimum or just the legs?
Not sure about that I would tend to think that it would be the cup dimensions. I sure would not rule out the possibility of a weak firing pin spring. What caliber is the rifle? Do you measure shoulder bump when you resize?
 
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