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Primer outward dimple

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Ok so I have seen something that I have never seen before.  I have been reloading for over ten years and have never seen a primer dimple outward before.  I am reloading 6.5 Creedmoor with Hornady 140 grain ELD-M bullets.  I resized brand new Lapua brass and trimmed to .01 inches (1.910") from the max length and used CCI small primer seated in the pocket.  I was loading up a ladder test with Superformance and Staball 6.5.  I loaded up 3 grains below max charge and was going up .2 grains from there, the first round dimpled outward at 42.2 grains of Staball 6.5.  Never seen it and the speed on the crony was 2580. 

I am shooting a new Uintah Precision AR10 with a bolt action on the upper, so not a standard bolt with a spring behind it.  It has a precision trigger on the lower from Uintah.  So basically the firing pin is a free floating pin much like a gas gun.  Would this be over pressure?  

The next round had a soft strike on the primer and failed to fire, I tried again and it failed to fire, but there was a small dimple on the primer.  I tried to fire a third time and it fired and made an outward dimple same as the first primer.  Would this be cause by the free floating firing pin?  When I fired factory Hornady 143 ELD-X, no issues at all and the primer looked like a normal fired primer.

Any suggestions?

D919F245-A52B-4FDD-816F-86C102C693C8.heic

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head space is too loose or very high pressure. I am guessing the head space as you would see other signs of high pressure.

your link doesnt work for a pic BTW

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Looks like your primer was pierced, then it looks like your primer filled the bolt face. Looks like an extractor mark on the shiney part of the case head. Did you feel any gas come back in your face when you fired that case? 

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Usually when something like this happens the primer pocket around the primer is black. Can you post a pic of your bolt face?

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I will post a pic of the bolt face soon,,,,,no, did not feel any gas on my face

 

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What was really a mystery to me was the light firing pin misfires on the primers, almost as if the pin was too short.

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As far as the light strikes on the primer, it sounds like Del said a head space issue. If you are sizing your cases to much, it will cause your case to swim in the chamber, when the firing pin hits the primer,  the case moves forward in the chamber and the firing pin isn't delivering enough force to ignite the primer.  Do you have anyway of measuring your cases?

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I have the Hornady gauge that will give me the shoulder measurement, is that what you are talking about?

 

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Will do, that would let me know the amount that I am resizing……will also check my reloading dies first to see if I had them adjusted correctly.  Thanks for the advice!!! I was just panicking a bit since I have never had this happen,,,,,never too old to learn!!!

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You said that your reloads were with a SR primer and this happened, and you had no problem with factory ammo, and I'm assuming that was with a large rifle primer.  With the data that you loaded the case with, did it call for a SR or LR primer? Don't know how much difference it would make between the 2 primers.

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heres a better view as he had the org pic there.

you can see black on the 11-12 oclock position, on the pocket hard to tell if the primer is pierced.

I'm thinking you resized your brass way to much like 10 turkeys mentioned above.

you can also see the machine marks (small light ring) in the bolt face where your case came back and smacked it. I bet you will find the same mark on your bolt, and your bolt isnt square to the round hence the heavy mark on the bottom by lapua and the light mark above. (squareness is not that big of a deal

case.jpg

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