I picked up this proof shotshell awhile back. I’m guessing that is was made back in the 50s or 60s. I know it was used by the gun manufacturer to test production shotguns. The shell is paper, and 2.3" in length. I was wondering what the amount of powder in one of these would be in relation to a similar size sporting load.
I would guess they still employ a similar testing method today, but wonder if there was there a “proof” blackpowder shotshell produced ?