Condensation on case

[Josh06]

Need some validation to set my mind at ease. A few weeks ago I was shooting my 280ai with a load that was previously worked up and safe, no pressure and below book max. I ended up having 2 pierced primers but believe it was due to condensation on the cases from keeping them in a cooler since it was over 100 degrees. I fired a total of 10 rounds, mostly pulling out of cooler, wiping the condensation then firing. The pierced primers were mag fed, didn't wipe off right before chambering so my theory is condensation developed on the cold brass while it sat in the mag and that caused increase in pressure leading to pierced primer.

 

[ShtrRdy]

That seems like a possibility.

 

[Pdyson]

I’ve never had a pierced primer, had hundreds flatten out and a few got loose and fell out Of my AR15. But the only other Pressure signs I’ve ever gotten were a sticky boat lift, shaving brass, and ejector marks on the head. If possible condensation is the only difference between those 3 and all the others of the same batch fired, I’d say youre probably onto something.

 

[baldhunter]

Could be.Codensation could affect the brass expansion in the chamber causing a pressure spike.The only primers that I have had pierced where CCI Large RIfle primers.One time the absent primer piece actually locked up the firing pin inside the bolt,leaving the rifle temporarily non-functional.Had it happen several more times with CCI Large Rifle Magnum primers in a different rifle.It didn't affect my rifle but a few failure to fire primers made me switch brands.

 

[Mikecr]

Why cool brass below dew point?
Is that what you do while hunting?

 

[Josh06]

Could be.Codensation could affect the brass expansion in the chamber causing a pressure spike.The only primers that I have had pierced where CCI Large RIfle primers.One time the absent primer piece actually locked up the firing pin inside the bolt,leaving the rifle temporarily non-functional.Had it happen several more times with CCI Large Rifle Magnum primers in a different rifle.It didn't affect my rifle but a few failure to fire primers made me switch brands.

I'm using CCI Large Rifle Magnum primers in this load. It happened to me again today, fired 2 shots, 1 fine and 1 pierced. Same thing as you, a piece of the primer locked up my firing pin, had to take the bolt apart and clear it. I went ahead and pulled apart the 25 of these I had left.

 

[C-130 Dude]

Need some validation to set my mind at ease. A few weeks ago I was shooting my 280ai with a load that was previously worked up and safe, no pressure and below book max. I ended up having 2 pierced primers but believe it was due to condensation on the cases from keeping them in a cooler since it was over 100 degrees. I fired a total of 10 rounds, mostly pulling out of cooler, wiping the condensation then firing. The pierced primers were mag fed, didn't wipe off right before chambering so my theory is condensation developed on the cold brass while it sat in the mag and that caused increase in pressure leading to pierced primer.

Thermal dynamics is at work here. Assuming you had the rounds "on ice" for enough time to cool them down to the ice chest ambient temp, when you removed them from ice, the rapid rise in temp (100° outside) would indeed cause condensation. Wipe off the rounds prior to loading in mags. Introducing moisture in your gun anywhere is not good. However, over heated rounds may see a pressure rise, not so much cold ones. Depending on powder type etc.. Think summer shooting vs winter shooting. Why you experienced popped primers is another issue here. Anyone got thoughts?

 

[Josh06]

Why cool brass below dew point?
Is that what you do while hunting?

The dew point that day was 69 so it didn't take much.....should have added very humid on top of being over 100. So, the brass was probably around hunting temps.

 

[C-130 Dude]

I'm using CCI Large Rifle Magnum primers in this load. It happened to me again today, fired 2 shots, 1 fine and 1 pierced. Same thing as you, a piece of the primer locked up my firing pin, had to take the bolt apart and clear it. I went ahead and pulled apart the 25 of these I had left.

What did you find when you pulled them down?

 

[Josh06]

What did you find when you pulled them down?

Nothing out of the ordinary, checked a few of the charges and they were right on, bullets pulled out fine so there wasn't any cold weld. I scoped the barrel and saw what may have been a carbon ring so cleaned it really good and it's gone now.

 

[C-130 Dude]

Nothing out of the ordinary, checked a few of the charges and they were right on, bullets pulled out fine so there wasn't any cold weld. I scoped the barrel and saw what may have been a carbon ring so cleaned it really good and it's gone now.

How did the primers feel when you seated them? How is your firing pin? Hope you didn't suffer any damage.

 

[David_h]

My first thought is that an overpressure situation would show other signs too; not just pierced primer. By chance was there any cratering around the primer where the firing pin struck it? My 10 month old BAR 300 WSM showed cratered primers and two pierced primers without any other signs of overpressure so I guessed that the firing pin and/or spring was weak or maybe the bolt face hole was too large for the firing pin. I'll never know because Browning didn't give me any feedback, they just sent me a brand new identical rifle as replacement.

 

[C-130 Dude]

My first thought is that an overpressure situation would show other signs too; not just pierced primer. By chance was there any cratering around the primer where the firing pin struck it? My 10 month old BAR 300 WSM showed cratered primers and two pierced primers without any other signs of overpressure so I guessed that the firing pin and/or spring was weak or maybe the bolt face hole was too large for the firing pin. I'll never know because Browning didn't give me any feedback, they just sent me a brand new identical rifle as replacement.

I just hate it when they do that. At least they honored your warranty. That said, it would have been nice to know what (if anything) was wrong. Does make you wonder though. Hmm...

 

[Josh06]

My first thought is that an overpressure situation would show other signs too; not just pierced primer. By chance was there any cratering around the primer where the firing pin struck it? My 10 month old BAR 300 WSM showed cratered primers and two pierced primers without any other signs of overpressure so I guessed that the firing pin and/or spring was weak or maybe the bolt face hole was too large for the firing pin. I'll never know because Browning didn't give me any feedback, they just sent me a brand new identical rifle as replacement.

Yes, there is cratering but I've had other guns that do this because of oversized bolt face holes so without any other pressure signs I don't worry about it. It's a savage so I think I may just order a new bolt head and see if that helps. Here is a picture of the 2 rounds from today, see anything I am missing?