An OLD Ammo question..

[skeet]

Maybe someone can identify the "cartridge" pictured. Some info on it. The bullet measures approx .569-570... the rolled paper "case" measures approx .620.. Length is approx 2 inches weight is approx 520 grains total. There is a thin cup in the rear of the "case" holding the powder in. Have a couple of these and trying to figure out what they are. Any help would be appreciated. Burnside cartridge..Old Spencer pre brass case??