Re: .410 brass shells: make your own!
use large pistol primers is my recommendation instead of large rifle. I think a shotgun primer is just the equivalent of a large pistol primer anyway, it's just set in a different/larger case.
Still haven't ordered any water-glass to use yet, this project will get underway down the road, I promise! Just busy lately with little time to reload. (relatively that is)
"Loud noises don't end gunfights.... well placed shots do."