My friend Markethunter mentions the industrial shells as raw material for loading. They are common 3 1/4 inch cases and may be suitable for loading 2 1/2 ounces maximum loads, only marginally better than factory loaded buffered copper coated WW 2 1/4 ounce tens, an awesome load in itself. I may have a few of those wonderful shells left from the pre-steel days. However, RMC offers eight gauge 4" brass shells for reloaders (well, all eight gauge shooters except Markethunter are reloaders, including eightbore). I use the RMC brass 3 1/4" shells, but would try the 4" brass if I had any. One of my eights is nitro proofed for 3 3/4" shells and 2 1/2 ounces of shot. I would be willing to shave 1/4" from the 4" RMC brass and see how much shot I could get in there. I don't think the nitro proved Greener Royal is going to explode with any load I would dare to fire in it. Markethunter knows where some of those 4" brass shells live. Maybe he could get the owner to gift me a couple for experimental use.