I'm not going to stick by the rules but:

Light - 8x68S Mauser 98 bolt action or Mannlicher or similar, scoped
Medium - .375 H&H Mag - Mauser 98 bolt action, scoped
Heavy (bottom end of the heavy range) - .450 NE double rifle (or similar eg .470, or heavier .500 etc)

I would add something in the .22 RF, .22 Mag RF, .222 range for small game, plus of course at least one shotgun.