Blown primer?!?

[CanusLatransSnpr]

Hey all! Well, I had an interestig occurence yesterday while I was shooting. I was working on some load development for my .243 Win. so I chambered the fouling round, touched the trigger, and then chambered another round. After I chambered the next round it occured to me that I needed to check the primer to see if it was flattening, the previous load was a little hot and flattening primers so I backed it off .5gr., and I noticed the primer was missing from the case and there was a raised circle on the head stamp from the hole where the ejector come out of the bolt face. This scared the shit out of me. With caution, I shot 2 more times and noticed similar pressure issues but, not quite as severe. As I sat there and scratched my head and my ass at the same time it occured to me that I didn't mop the chamber after I cleaned the barrel on this rifle. Also, I could smell Butch's and it was all over the action. Could a wet chamber cause such a severe pressure spike and is everything ok with my rifle? The only thing I could notice is an ever so slight ring in the bolt face where the primer pocket sits against it, can't hardly catch the tip of a knife blade with it! I will say this, I am grateful that neither my cousin or I were injured from this!! As always, I appreciate the help guys! Thanks!

Mike

 

[Jay Christopherson]

I'm sure someone with specific expertise will answer, but here's my experience (from a long time ago in a land far, far away):

I had the exact same issue with a .270Win firing factory ammunition. The first round I shot, the primer blew and there were ejector marks. I had a hard time believing that factory ammo was overpressure, so I took a round from a different box I had with me (again, factory ammo) and this time the primer did NOT blow, but the round show signs of excessive pressure (flattened primer, etc...). I continued to shoot (cause I was dumb) and after about 3 or 4 shots, all those pressure issues/signs went away.

When I thought about it, I had the exact same revelation you had: I had just cleaned the rifle and had swabbed the chamber heavily with solvent. I had left it sitting with the solvent and forgotten to swab it out and dry it before firing it.

That doesn't happen to me anymore- this was a long time before I started reloading; I was still just shooting a few times a year to keep my skills up for hunting. However, it's always stuck with me and I've never gone to the line since without swabbing the chamber thoroughly.

Anyhow, IMO, the answer to your question is "Yes, a wet chamber (i.e., flammable solvents) can cause a pressure spike like that". Even with factory ammo.

 

[CanusLatransSnpr]

Thanks jaychris, I appreciate the reply! Unfortunately, you had to experience the same thing I went through but, you confirmed my hypothesis of the wet chamber. However, it does give me some security that my rifle is ok if you continued to shoot and had no problem. Thanks again!

Mike

 

[bozo699]

Mike,
Absolutely it will,...think about it? (I have done it more than once)
you would think I would learn anyway you have a chamber with tight clearances even a factory chamber is still measured in the thousandths and you add liquid?? somethings got to give, also it's on the same thought as (lightly) lubing your cases for fireforming,..you do it why?...so the case doesn't stick to the chamber wall,...it can flow and form itself. well yours formed itself alright!..right out the firing pin hole in the bolt,..it was the only escape. If you live long enough and shoot enough rounds it probably will happen again.
Wayne.

 

[CanusLatransSnpr]

Yeah Wayne I agree, somethings has to give! I hope I learned my lesson and this won't happen again but, I am human so I will make mistakes ! No offense to any blondes out there but, that truly was a blonde moment that I experienced lol! Thanks Wayne!

Mike

 

[Keith Glasscock]

I have had the same experience. In my case, I've had it happen from forgetting to mop out the chamber, and also from shooting in the rain. Water, like any other fluid is incompressible and makes the pressure go up.

If you shoot a hot load, and it's raining, you have to do everything in your power to keep both your ammo and your chamber dry.

Just my experience shooting matches...

 

[bozo699]

I have had the same experience. In my case, I've had it happen from forgetting to mop out the chamber, and also from shooting in the rain. Water, like any other fluid is incompressible and makes the pressure go up.

If you shoot a hot load, and it's raining, you have to do everything in your power to keep both your ammo and your chamber dry.

Just my experience shooting matches...

Busdriver,
That is exactly right, however you and I have the ability to keep it dry or make the call, enough I will disqualify or the match will get called. I have often wondered about our Boys in the service in particular WWI &WWII, Korea, and Vietnam how they kept there weapons dry enough and clean enough to function? I mean if your on the line and your BR rifle malfunctions you don't get to take the wood home, if your on the line in a foreign country and your weapon fails??.. you don't come home!! or maybe your whole company doesn't come home !! I can't even imagine the feeling or the pressure one would have but it has to be intense just to say the least. I know I took this off topic but it is something to think about!
To all you service men and women for your total dedication in keeping all of us civilians safe from tyranny and harms way,....
THANK YOU ALL!! very very much!!
Wayne.