Gentlemen,

best regards from the old continent. As far as I know, the H-Mantel was never intended for thickskinned game but rather deer sized critters.

The job of thick skinned game was left to the TUG Bullet (Torpedo Universal Geschoss by Wilhelm Brenneke; produced and loaded under licence by RWS until just about 10-15 years ago).
This seems to me the bullet shown by luvtosafari above.

The TUG is still produced both by RWS (sold under the name UNI Classic) and by Brenneke GmbH, Langenhagen.
Both can be bought here as components in Germany.

https://www.grauwolf.net/wiederlade..._verwendung=224&grauwolf_kaliber=242

I hope this is usefull.

Member of the Merry Band of turdlike People.