I have an odd question. I'm far from a rookie when it comes to gunpowder and reloading, and have been using various surplus powders and such for decades. I've even seen what happens when powder goes bad. This is a little different though, and has me scratching my head.
I have a bunch of .223 reloads that are cracking. Something like 1500 rounds that I loaded over a year ago, and they all crack at the neck when fired, some are even cracked from just sitting. They are a couple different bullet types, and at least two different lots of brass.
I've never had anything quite like this happen before. I've found old reloads that have cracked much the same after 20 or 30 years, but not recent stuff. They all had two things in common: 1. The brass was all stainless-steel tumbled, shiny inside and out. 2. They are all loaded with some surplus Data 2200 powder that I bought at a gun show a couple years ago.
I've been SS tumbling for several years now, never noticed a problem. I'm a little worried that problems like this could show up in other ammo I've loaded, like nice match 30-06 and such, but so far nothing similar.
That leaves the powder. Honestly it looks and smells fine. I loaded a few more with the same powder and they shot fine. I pulled down a bunch of the ammo from last year and there was no sign of any corrosion or tarnish. I posted about this in another thread a while back, with no resolution. Ammonia exposure of all this brass is extremely unlikely. I know that annealing plays a part, but this is every single round, of the same type of brass that I've never had an issue with before.
If ball powder like this was starting to deteriorate, any chance it could affect the brass like this, just sitting loaded for a year or so? It seems like a long shot to me, but something is clearly going on here, and it's got me puzzled.