What the? Ammo cracked?

[Bhamrichard]

Went out yesterday with a friend to pop off a few rounds. Ended up taking along my S&W .38 with us. This .38 (model 15-3 revolver) was left to me by my father when he passed away, always been very accurate and fun to shoot. I had some older ammo socked away that I decided to go ahead and use up. It's very likely this ammo was also part of my dads stuff, as it was unboxed and unlabled.

After popping off a few rounds, I had a very hard time dropping the casings from the cylinder, literally had to force the push rod to clear it out. I got to inspecting the empty casings after that I found what you see in the attached pictures.

There's a split in the side nearly from end to end, I'm not familiar with this ammo, it's stamped "W-W 38 special" I couldn't tell you who made the stuff.

What, if any, danger would this pose? I've never seen ammo split like this and it convinced me to refrain from shooting any of the rest of it.

 

[Curator]

The cases are splitting due to age-hardening or over worked brass. They might be old reloads or just plain old. I have had every case in a pre-war (1940) box of factory .44-40 Winchester ammo split just like that. Chances are to real harm would befall you if you simply shot them up and disposed of the brass. Cracked cases happen with reloads occasionally, and its no big deal as long as they aren't overloaded. Be sure to clean any carbon out of the chambers afterward.

 

[tekarra]

Has the ammunition been stored near an ammonia containing compound? It appears the case cracks could be season cracking, a common phenomenon in cartridge brass that has been in contact with ammonia vapours. You should pull the bullets on the remaining rounds and dispose of the components in a safe manner.

 

[Bhamrichard]

Far as I know it's been stored in a box in the closet. He purchased the revolver in 1969 so the maximum age the ammo could be would be about 42 years. I don't know the actual age but it would have been unusual for him to keep ammo that long, he liked to go out plinking too much with it. Anyway.. I still have 6 left that I will not be using

Thanks for responding guys

 

[wilkersk]

Its known as "de-zincification". Cartridge brass is made of 30%zinc and 70% Copper. Over time, zinc depletion at the grain boundries results in intergranular corrosion, which can cause exactly this type of failure in older ammo.

 

[atomd]

I have had this happen with some old ammo. I had some old .357 rounds where the case completely separated at the rim while being fired.

 

[NavyLCDR]

Yep. Really nothing too unusual about that for old ammo or reloaded cases. I used to reload .460 S&W until the cases would fail like that.

 

[Jim K]

Wilkersk is correct, but the actual cause is the powder; powder with un-neutralized acid in it is the villain. That situation is common with wartime ammo which was produced in a hurry. (The crack will occur on the side of the case that was down when the ammunition was stored.)

Jim

 

[351 WINCHESTER]

Well, that explains why some of my older .351 ammo split and cracked.

 

[rcmodel]

What, if any, danger would this pose?

In a low pressure caliber like .38 Special, none.

Just shoot it up and throw away the brass.

As others have noted, it is quite common in handgun brass that has been reloaded too many times.

It's another issue with hi-power rifle brass.
In that case, it is not safe to continue shooting it as a catastrophic gas leak could blow you up.

rc

 

[nitetrane98]

I did not know about the "de-zincification". Pretty common in reloaded .38s I used to do. Usually around 10-12 trips. Kind of an "I'm done." sort of deal.

I guess the powder part makes sense but evidently it can happen on old grungy cases that have been exposed to the weather for a long time. The kind that are real dark brown and won't tumble up shiny. I'm currently working through several hundred .45acps that I found laying in the dirt and mud. Thought I had found the motherlode but I'm experiencing a split case like that now and then. Fairly low pressure loadings. They'll all get chunked now after they get fired.