Gentlemen,

I would consider these three rifles:

A) a Heym Express in 404 Rimless NE, with a low power scope like 1,1-4x24 of a good manufacturer like Zeiss or Swarovski; (ammunition: handloaded 400gs Woodleigh SPRN or Barnes TSX for ca. 700 m/s)

B) a reworked Brno 458 Lott (5 shots in the magazine), also with a good variable low power scope
(ammunition would be a 450grs TSX loaded to 700 m/s)

C) a Heym Express in 500 A-Square with a red dot sight (ammunition loaded down to 500 NE level with a 570grs Woddleigh SPRN and Hydrostatic for follow up shots)

stocks made to fit, every rifle tested on the range for correct sighting, abd shot in the shooting cinema for bringing all issues to daylight the rifle might have if operated in a hurry

Testing with standard ammunition to see whether the shooter is up to the task/caliber, and stepping down ballistically if not...

best regards
Rolf