panther shooter that appears to be lead buckshot per the marking on your boxes seems similar to what would have been lead #4 buck here in usa.
That was some good stuff many many moons ago when it was legal, various buckshot were legal for deer many moons ago when I was shall we say younger also! When it was legal long ago to use lead one could literaly knock them off at a good distance if you were a good wing shot and that stuff you have was a pass thru only needed to hit with one or 2. many many years ago I belly crawled up on a flock on the ground and line up the heads smoked 5 with a 10 ga 3 1/2 mag and lead. got a bloody nose from the recoil but it was worth it. ah the days of lead it killed em dead, enjoy those rounds wish I had some!