I was talking to our local HVAC guy a while ago and the subject of trap shooting came up. He was telling me both his daughters are on the local high school clay shooting club. Between practice and matches they go through a case or more of ammunition a week. I said I thought he might be able save money by reloading their old casings. He agreed it would be less expensive, but the league rules stipulate that no reloads are allowed. Given the price of shells around here that's about $250.00 to $300.00 a week in ammunition
I mentioned I'd bought a Browining 12 ga. pump shotgun for that purpose back in 2019. My timing couldn't have been worse. A friend of mine had talked me into the purchase so we could go to a couple of the local ranges, and he could teach me the fine points. Along came the pandemic and all the ranges closed. By the time they opened again he started having problems with his hands and could no longer shoot. To this day the shotgun has never been fired. It's sitting in the case while I look for a place to use it. I've found a couple ranges that do allow the public in, but most are 50 miles or more away.
Getting back to the original subject of the viability of older shells, I did buy a couple 10 count boxes of Fiocchi 12HV4BK shells from a local resale shop. They turned out to be only a couple years old assuming they're in the original dated box. They weren't at bargain basement prices in that I paid $10.00 a box, which is close to retail around here.