Wet Cartrage = loose primers

savage440

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I went shooting the other day 44.5 gr varget 178gr amax. I loaded up 100 rounds shot them all but the last one fell in the snow. I picked it up blew it off, it was still a bit wet. When I shoot it the gun made a funny sound, the bolt was stickey so I looked at the case and the primer fell out! Does wet brass cause pressure problems?
 
Not in my experience using both factory and reloaded ammo. Are you sure you didn't get a muzzle full of snow picking up the round? That could increase pressures.

Assuming the round wasn't in the snow very long, I can't imagine any moisture got into it via the neck (loose crimp). I'd be double checking my scales and measures ... something sounds a little hinky.

I've shot in the pouring rain and even ammo that is fairly soaked has never shown a difference in pressure, so I doubt it was the moisture on it.
 
Water may have stopped the case from being able to grip the chamber wall. Funny things can start to happen when the case is slick or lubed. It can increase the force that acts on the bolt face.

Or a bit of ice between the case head and the bolt allowed the primer to back out, but that seems a stretch (pun, not intentional).

Was the primer pocket loose?

Cheers
Trev
 
Water may have stopped the case from being able to grip the chamber wall. Funny things can start to happen when the case is slick or lubed. It can increase the force that acts on the bolt face.

Or a bit of ice between the case head and the bolt allowed the primer to back out, but that seems a stretch (pun, not intentional).

Was the primer pocket loose?

Cheers
Trev

Yes the primer pocket is loose now
 
What kind of brass? I've had this happen with Federal brass on the first reload with light loads before.
 
Yes the primer pocket is loose now

My nickel says it had little, if anything, to do with the wet round.
Been wrong before. Can afford to lose a nickel. :)

Coulda been something from being wet, but I'd be leaning in the general directions of 'stuff happens' or pressure issues unrelated to the drop in the snow.
Powder charge measuring error, case capacity being out of line, softer case than the rest (over annealed at some point), etc.

Dunno if you are at the top, bottom, or middle of the road for your cartridge, as you have not mentioned it, but if you are skinning along at the top end, that'd be an easy guessed at diagnosis. Being that you found the one combo of things (case/powder/bullet/seating/etc.) that popped a primer.

Meh. Scrap the case, carry on, and wipe dropped ammo dry, before use, eh.

Cheers
Trev
 
If the cartridge was wet enough a bit of water may have be pushed up into the throat and into the barrel. With the barrel partially obstructed with water it is possible pressures were raised enough to blow the primer. It is also possible the barrel could also now be "ringed".
 
is it first load through that brass? is your load at the top end? most of all is it federal brass? ive had a few primers pop all of which have been federal brass there primer pockets tend to be looser and the brass seems softer in my experience. i doubt it was the wet cartridge that caused it but if its a load closer to the top end it is possible
 
I have seen primers pop in the bcra sniper match when it was raining. My 2c is with water on the case (remember a fluid is for the most part non-compressible ) the water would have taken up some chamber space that the brass would normally expanded into, this would basically made your chamber tighter and higher pressures would result.
 
The answer is probably in "Blowing it Off" versus wiping it dry.
The case being wet in the chamber, and under pressure it would be lubricated with a thin layer of water.
 
I have popped primers due to wet rounds.

As said previous, water does not compress (neither does Hoppes #9.......ask me how I know) in the chamber taking up space the brass would have expanded to.
 
IDoes wet brass cause pressure problems?

Yes. Think about it - water is 'non-compressible' and eats up room for brass expansion in the chamber. And there is the steam aspect to consider on top of that.

I'm throwing away any of the brass I shoot in competition when it rains ... otherwise, I'm dealing with 'loose' primer pockets when I reload. You will see pressure signs on the brass and also able to measure a distinct difference in the web between 'dry' fired brass and 'wet' fired brass.
 
If the cartridge was wet enough a bit of water may have be pushed up into the throat and into the barrel. With the barrel partially obstructed with water it is possible pressures were raised enough to blow the primer. It is also possible the barrel could also now be "ringed".

Seen this before as well, probably had droplets on the bullet and this will increase pressure significantly. Living in the land of ice and snow and having over 1/2 my range time during snow months this has happened to me several times. Absolutely must completely dry any dropped cartridge before firing, I open my parka and roll it across my stomach, on my shirt until bone dry.
I doubt there would have been enough to "ring" your barrel or I doubt you would have been able to open the bolt. This is the same reason we tape our muzzles in wet weather, think about it!!
 
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