Above is a picture showing some 7 x 57 Mauser cases after firing them on July 4, 2003. The cases had been loaded in 1984 with BL-32 (military surplus) stick powder (roughly equivalent to IMR 4895). I recall that when I loaded the ammo in 1984 I noticed a few specks of "rust" in the powder, but the powder did not have an acid odor and it seemed to work just fine in 1984. But, something happened (or continued to slowly happen) in the next 19 years while the ammo was in storage.
Please note, before I fired this ammo in 2003 all loaded cartridges appeared quite normal on the outside.
Case #1 -- This was the second round of a 5-shot group with Remington brass, first reload, 44 gr. BL-32, 120 gr. Sierra bullet. The 5-shot group was 0.52" at 50 yards. The brittle case neck is split/cut halfway through. The other four cases did not split. The average velocity was 2826 ft/sec and the extreme spread was 114 ft/sec.
Case #2 -- This was the first round fired with a case that showed a vertical neck split before firing. Now the fired case shows an additional connecting horizontal split starting at neck-shoulder junction. This was Winchester brass, first reload, 42 gr. BL-32, 130 gr. Speer PSP.
Case #3 -- This was the second round fired with the same load. The case "lost" its neck. Apparently it went up the bore with the bullet.
Case #4 -- This was the third round fired with the same load. The case neck stuck in the forward end (note taper) of the chamber. This piece was retrieved with a bronze bristle brush without difficulty.
Although scientifically interested in what was going on, I quit shooting out of concern for my own safety, and the condition of my rifle. Back home I pulled the bullets from all 32 unfired rounds. In all the rounds I found considerable green sticky crud in the powder that was near the bullet bases. And, all the bullet bases were severely corroded. The powder had all gone “bad” and the cases were, of course, too brittle and weak to ever be reused.
