270 Win brass failure

[oldfortyfiveauto]

I was shooting up some old Winchester factory ammo practicing my off-hand skills. This ammo was probably from the late 50's or early 60's judging from the box. 100gr soft points. As you can see from the photos there is a corresponding burn mark in my chamber. There wasn't any external indication on the brass before shooting. I've shot all kinds of old milsurp, some from the 20's and not seen anything like this.

My poor old 270 has taken a beating. I managed to also have a bad batch of Winchester LR primers that burned through. My bolt face looks like I took a torch to it. Winchester replaced all my primers. This was not an unusual problem a few years ago.

 

[just country]

morning, I loaded some rounds for my 257AI. set about 2yrs. went to range.

had the incident happen. thru all of the ammo away. old H4831 powderlightbulbgun)

 

[philipbrousseau]

Just could have been galvanic corrosion possibly& not the powder. and 1920's ammo is corrosive isn't it?

 

[J E Custom]

Just could have been galvanic corrosion possibly& not the powder. and 1920's ammo is corrosive isn't it?

The powder and primers were both corrosive especially if the degraded from time and moisture.

The older powder breaks down and becomes acidic over time and can change burn rates causing this
problem. Some times it is bad enough to eat through to the outside.

All of this ammo should be tossed for safety and to preserve your rifle. look at the chamber with a bore scope after a good cleaning to evaluate it for possible barrel replacement or a 1 thread set back and fresh chamber clean up cut if the barrel is still good.

J E CUSTOM

 

[oldfortyfiveauto]

The ammo was probably early 60's. You can see the burn marks in the chamber, but just a hint of pitting.

 

[Dosh]

45, I pulled bullets from some 60's era 7mag, punched the primers and the primer pockets were eroded so bad the pockets were just a crater. I only wanted the brass which was useless. Don't recall when the corrosive type primers went out of production, but this was pretty bad. As mentioned, toss that bad stuff and start with new. Good luck

 

[oldfortyfiveauto]

Most commercial brass was noncorrosive by the mid fifties. I've shot a lot of old corrosive milsurp and not seem anything like this. Must be a reaction with powder gone bad.