So I know that ammunition doesn't last forever, but not all decay is created equally. I've seen both firsthand and in a number of posts here about what happens when rifle powder decays. Gunpowder becomes corrosive and melts through the brass case.
But what about shotshell powders? I've not heard as much discussion about them breaking down. I have a lot of old shells I found while doing some inventory around the house. Shotshell hulls are different, with almost no contact between powder and metal. Really only the primer cup touches powder, as everything else is plastic or paper.
The other complicating factor is that shotshells are made of all sorts of mixed metals. Some have brass heads, some brass plated steel, some zinc plated steel. Add to that the primers are made of multiple metals, so potential for dissimilar metal corrosion is set up. Add to that, they're kept in cardboard boxes in large numbers and taken out into humid conditions repeatedly.
The question is: when a hull is corroded, is it from the inside (bad and potentially dangerous powder decay) or the outside (ugly but harmless surface rust). Shotgun shells aren't as easy to pull as metallic loading cases, but I did pull a few to see what is going on. I'm open to seeing what experiences others might have had.
Shell 1: a reload from 2004, Remington unibody hull, SR 7625 and a Win 209 primer. The box was partly used and likely went to a dove hunt somewhere along the way before getting forgotten in the back of the cabinet when I started carrying bulk dove loads.
This is four shells from that box. The one on the left looks fine, the one on the right is the worst (and the one I broke down to test).
The shot was dry and in good shape (not pictured). The powder was dry, and had no real problems. No acrid smell at all. Poured in a line and burned, it was consistent.
The inside of the primer and inside of the hull looked as good as new, so it appears to be just surface rust.
Shell 2: A factory loaded Winchester AA. It's probably from the early 2000s and spent most of its life in air conditioning, but the last 5 years were in a storage unit in North Georgia.
Cutting into it, the shot was good, but the powder is a bit more unclear. It had no real smell, but did clump together a bit. When tapped the clumps broke and it burned consistently.
On the inside, there were a couple of flakes of clinging powder but the primer looked shiny and new. I'm wondering if the clumping is something that happens with the factory powder (it's fresher? meters differently than canister-grade?) or a sign of something else?
But what about shotshell powders? I've not heard as much discussion about them breaking down. I have a lot of old shells I found while doing some inventory around the house. Shotshell hulls are different, with almost no contact between powder and metal. Really only the primer cup touches powder, as everything else is plastic or paper.
The other complicating factor is that shotshells are made of all sorts of mixed metals. Some have brass heads, some brass plated steel, some zinc plated steel. Add to that the primers are made of multiple metals, so potential for dissimilar metal corrosion is set up. Add to that, they're kept in cardboard boxes in large numbers and taken out into humid conditions repeatedly.
The question is: when a hull is corroded, is it from the inside (bad and potentially dangerous powder decay) or the outside (ugly but harmless surface rust). Shotgun shells aren't as easy to pull as metallic loading cases, but I did pull a few to see what is going on. I'm open to seeing what experiences others might have had.
Shell 1: a reload from 2004, Remington unibody hull, SR 7625 and a Win 209 primer. The box was partly used and likely went to a dove hunt somewhere along the way before getting forgotten in the back of the cabinet when I started carrying bulk dove loads.
This is four shells from that box. The one on the left looks fine, the one on the right is the worst (and the one I broke down to test).
The shot was dry and in good shape (not pictured). The powder was dry, and had no real problems. No acrid smell at all. Poured in a line and burned, it was consistent.
The inside of the primer and inside of the hull looked as good as new, so it appears to be just surface rust.
Shell 2: A factory loaded Winchester AA. It's probably from the early 2000s and spent most of its life in air conditioning, but the last 5 years were in a storage unit in North Georgia.
Cutting into it, the shot was good, but the powder is a bit more unclear. It had no real smell, but did clump together a bit. When tapped the clumps broke and it burned consistently.
On the inside, there were a couple of flakes of clinging powder but the primer looked shiny and new. I'm wondering if the clumping is something that happens with the factory powder (it's fresher? meters differently than canister-grade?) or a sign of something else?
