Age hardened brass?

[timkelley]

I had a number of rounds of 30-06 on the shelf from about 30 years ago. This morning I decided to take them out and unload them, thru the muzzle as it were.

Approximately 75% of the fired cases cracked at the neck, do loaded brass cases age harden?

If they do, age harden, when loaded, do they also harden when not loaded?

My worry is that all of my brass is of that vintage. There was a long period (nearly 20 years)while I lived in Cathedral City, CA. when no reloading happened. I guess what I am really wanting to know is if I need to anneal them all?

[Bent Ramrod]

This phenomenon used to be called "season cracking," and was a common occurrence in the old days before cartridge brass metallurgy and heat treatment had been worked out. Surplus military ammunition from WWI would often either crack on firing or be received in a cracked state by DCM buyers between the wars. I would imagine some brass occasionally makes it through the process with not enough neck annealing to have this happen.

The brass in the neck is put under tension when the bullet is inserted and spends years trying to compress itself back to its original diameter. Unless the anneal is right, this tension eventually cracks the neck usually in a line parallel with the centerline of the cartridge.

[geargnasher]

I was wondering the same thing. Someone gave me a few ancient boxes of .30-30 to use for the brass once, they were smokeless but probably from the 1950s or so, every single one of them split the neck. After splitting the first ten firing them, I went home and pulled the rest, those split when they were fired after reloading. It wasn't worth annealing them so I just pitched them all.

Gear

[zxcvbob]

I have a bunch of 7.62x25 ammo from the 1950's and a lot of them split or crack at the neck when fired. The gun doesn't seem to mind, and it's not really reloadable anyway (berdan primed)

[NVcurmudgeon]

I recently found a pile of old Krag cases at the range. The majority had neck cracks. I sorted out the uncracked necks and took them home for tumble cleaning and annealing, yielding 33 that looked good enough to load. About half had "Western 29" headstamps, I assume that means military contract 1929. There were a few Winchester, Western, and Rem UMC cases with headstamps that said, in part, ".30 Army" which predates any new factory case headstamps I have seen in the last 60 years. The balance were headstamped "Rem. UMC .30/40 Krag" which I know for sure was replaced by the current "R-P .30/40 Krag" headstamp in the early 1960s. So far 32 of the 33 cases have survived one firing with 16.0 gr. 2400 and the Lyman 314299 boolit.

The annealing technique I used was one in a recent Handloader or Rifle magazine article. You hold the case about in the middle and rotate the neck and shoulder in the flame of an ordinary parifin candle. When the case gets almost too hot to hold you drop it on a damp towel and then wipe it clean. It was the pleasantest annealing technique I've ever used, and appears to work very well. No lurking in a dark room where you can't be sure what the propane torch is going to set on fire, and no drying out cases that have been submerged. I like it!

[zxcvbob]

Have you ever tried annealing cases by dunking them mouth-first to the shoulder in a pot of molten lead?

[timkelley]

I tried annealing using hot lead once, the results were inconclusive. Half of the annealed cases still split next firing but I know they had been worked an awful lot. Perhaps I need to try the hot lead annealing again.

[Von Gruff]

I used the lead pot method ( hated cleaning the lead that stuck to the necks though) as well on some 7x57 cases that had been fired many times before they were given to me and I started to loose one or two from split necks after another 10 or 15 reloads. They stayed in use for another 5 or 6 reloads till I started to anneal with a gas torch every few re loads and they have had another 10 loads since then.
If the brass is annealed before re use it should be as good as new and suitable for many reloads. On low pressure loads I anneal every three re loads but for my high pressure - high velocity jacketed loads I anneal every time.

Von Gruff.