Never seem to have a had a problem is they have been stored o.k. A couple of years ago I was given a box of World War II Eley airgunner training cartridges. 12 bore with a tracer element. Normally I would have put them away as collector stuff but this lot had been stored badly and the heads were all verdegris and corroded. Out of curiosity I fired them at 25 sporting clays out of an old single. 24 went bang as normal with one failure. At least half still traced as intended and I got 23 kills with only one miss. Quite surprised as I didn't expect much and was just getting rid of them. I have used wartime issue .22rf. stuff and most of that fails with the odd click, then a delay before a bang and then a delay as the bullet strikes low.
A few years ago I bought a case of Hungarian 12 bore 'Nike' tracer cartridges. Great for shooting crows flighting in at dusk. I had three or four boxes left that had been well stored for only a couple of years. I gave a box away and the recipient said they didn't show a tracer. I shot a box and found the things no longer traced as before. Still have the one remaining box left over. No idea what happened to stop them working. The only other odd things were some 10 packs of 16 bore plastic French 'Starlett' cartridges. When I came to handle them the plastic broke up like egg shell. I guess they were of some sort of biodegradable plastic. They had been stored cool and dark. I shot the ones that remained whole and all that came out of the breech end was the brass head. Shot o.k. but totally disintegrated the case. Lagopus.....
