Hoping someone can help me with this issue. I am finding cracked case mouths on reloads that have been unfired since loading a couple of years ago. The cracks are so bad I can pull the bullet out by hand. They are very fine cracks but visibly noticeable. I inspect every round very well as I load. The problem is with several different calibers so I am not sure if this is normal. I even found some cracks on some 7mm loads someone gave me several years ago.

Posibly the necks had reached a hardness that allowed a bullet to seat but the work hardened stress finally just let go....crack

No, it is not normal.

I will make an assumption, please confirm this is the case.

Your reloads aren't on cases that have over worked case necks? Like 10 reloads without annealing the necks?

If that isn't the situation, you might have a stress corrosion cracking issue. Do you store your reloads near/with any cleaners that contain ammonia? Copper solvents with ammonia in particular? Ammonia fumes will weaken brass, and crack it where it is under stress, like the neck of a cartridge. Other chemicals can do this as well like chlorine.

Here is a good explanation of SCC in brass. http://hghouston.com/resources...ses/sc-cracking.aspx

Might not be your issue, but food for thought.

Jeremy

Other than the loads I was given, I can confirm that none of the brass has been loaded more than 2-3 times. The brass is old but I don't believe overused. You mention corrosion, all of the loads in question are badly tarnished and some show visible corrosion. All loads were stored in plastic containers of factory ammo boxes in a cabinet. No chemicals around that I remember.

The only common denominator I can find is age. Several different brands of brass, several different loads, etc. On the older stuff, about one in 10 is cracked.

I have had that happen very rarely on old(15-20 year) reloads. Nothing like you are experiencing. You definitely have some environmental issue going on. Could it be temperature variation?
If it was happening on only one caliber I would suspect a resizing die that is over working the brass but on several calibers?

Your brass is old, and possibly was from a brittle lot to start with. Reloading it didn't help.
Trash it and move on. It is rare for brass less than 75 years old to crack on it's own but it happens.

Thanks for the help. I guess my biggest concern is if I am doing something improperly that will affect more loads going forward. I have noticed that the RCBS case lube I use tends to tarnish cases very quickly if I don't clean them really well after loading. I use a very small amount of the same product on the inside of case mouths with a proper brush. Could this be causing corrosion ?

That is possible. Maybe try a dry film lube like One Shot.

I use RCBS lube, but have never seen any corrosion from it. I wipe off the case after loading, but I don't go to any extreme cleaning measures.

Jeremy

quote:

Hoping someone can help me with this issue. I am finding cracked case mouths on reloads that have been unfired since loading a couple of years ago. The cracks are so bad I can pull the bullet out by hand. They are very fine cracks but visibly noticeable. I inspect every round very well as I load. The problem is with several different calibers so I am not sure if this is normal. I even found some cracks on some 7mm loads someone gave me several years ago.

I am going to provide an answer that no one wants to hear, or will take seriously, because, it is not something they want to believe.

Old gunpowder.

Gunpowder has an indefinite shelf life, not infinite, indefinite. Just when it breaks down to uselessness/dangerousness the exact date is unknowable. Sort of like life, there are all sorts of actuarial tables giving predictions just when you will cease to be, but the exact day and time, we don’t know. But it will happen to you, and to your gunpowder. As gunpowder breaks down it releases nitric acid gas. Nitric acid attacks brass, the most stressed part of the case is going to fail first. I had over 700 LC match 308 cases crack their case necks because I had loaded those cases with military surplus IMR 4895. The powder had little to no smell, but it was outgassing enough to crack case necks after a couple of years.

Some really good pictures of gunpowder going bad in the case in this thread:

Has anyone else had Vihtavuori N140 corrode in loaded ammo?

http://www.falfiles.com/forums...thread.php?p=3745264

Some good pictures of old military ammunition. Something else shooters don’t want to hear, that old gunpowder will blow up your gun.

When milsurp goes bad….

http://castboolits.gunloads.co...ilsurp-ammo-goes-bad

Have had a lot of 7.65 Argentine for several years; SF 80. I have shot about half of it but hadn't shot any for a couple years. Took some out this last summer and loaded 5 into the mag of my M1909, took up a good sitting position and set the sights at 600m for a sage brush on a hillside about that far away. Fired the first shot and smack into the sage, worked the bolt and fired the second shot and smacked the sage again. worked the bolt and the third shot wen high right and away.......dropped the but of the rifle out of the shoulder and immediately noticed smoke curling up out of the receiver........not good

Opened the bolt and the case came out minus the primer Checked the other 2 shots and they all had high pressure signs. Stopped shooting.

I finally got around to pulling the rest of the bullets and about 2/3 had severe corrosion inside the cases and on the bases of the bullets. Picture shows 2 of the fired cases including the blown primer. Middle case shows corrosion inside the cases. Bullet on right shows corrosion on the base. Other 2 bullets cleaned up nice with polishing. Powder looks good with no discoloration and smells good but will make good fertilizer

Very interesting thought on the powder. I am not sure if I am able to post a picture on here but I have one showing a cracked case with the bullet still in it and a bullet I pulled from another. Both have a black ring around the contact surface of the bullet and the top of the brass.

That is true; when powder turns bad, it no longer smells like ether and has an acidic smell and has brown dust in it. You can tell right away if it is bad. Excessive heat will kill powder; otherwise it lasts a very long time.
Speaking of 7.64 Argentine, I once had two cases (3000 rounds) of it that had cracked necks; probably the result of powder turning bad, which it had started to do.

This type of thing has been around for many years !!! The Brits in the 1800s saw it in places like India.
thunderstorms in the wet season produce ammonia compounds which attack the brass.Stress by overworked brass adds to that Also moisture and oxygen. The total effect is called "stress corrosion cracking " They've found many years ago that the solution is to anneal the necks occasionally.
Why haven't you 'shooters' ever heard of this before ???

A vinegar cleaning solution can damage brass.

Thank you all for the help.

Picked up a bunch of new unfired brass that was around 25 years old. Some was Win and some was Rem. All was 264 Win calibre. The first box I loaded about 1/2 of the necks split when fired. I annealed the necks on the rest of them and they were fine. Suspected they had been exposed to something but was never sure what.

That's happened to many ! The Brits called it "season cracking " as it only happened in the wet season ! Thunderstorms > ammonia compounds > cracked case necks ! Even new , still in the box ammo !