Shotgun primers go in the scrap steel bucket to be sold when the pile gets big enough.
That's better than the whack job at the club who used to drop one spent primer into the shot cup as he was reloading. He loaded reduced skeet loads and used the primer to take up space. Too cheeeep to load a correct load.
Not something I'd do, run steel down my barrel even if it's inside of a plastic shotgun was.
Like I said, whack job.
He was also the guy who was outraged when he got kicked out of the club for game law violation(s)---5 dead deer and 1 license, AR-15 in a shotgun only area. Didn't think it was "fair" he got kicked out.
He's since past away, not a whole lot of mourning for him.
The rifle and pistol primers go in the brass bucket to be sold for scrap. Local scrap yard views it as just more brass.