The need to go beyond just using Deer calibers to put the real smack-down on heavy game.
My observations using these -
9.3mm/35 caliber: 9.3x62 ammo is actually quite reasonable at $29.95 per box from TradeEx (
https://www.tradeexcanada.com/content/prvi-partizan-93x62-ammunition-285gr-sp-- ). Heavy bullets are available, 35 caliber 310gr and 9.3mm 320 gr. I like my 9.3x74R Ruger No.1 because it can be handloaded well beyond factory ammo ballistics. Wide selection of 35 caliber bullets, unlike for the 9.3, including 158gr pistol bullets for plinking. My custom 350 RM can fire 310gr bullets at 2500 fps. OK performance, adequate power to break shoulders on heavy game except at longer ranges.
375 caliber: don't see an appreciable or any performance improvement over properly handloaded 9.3/35 in comparable bullet weights. Has only 4% more cross-sectional area than 9.3mm.
45 caliber: real heavy weight bullets like 500gr+ available for 45-70 or 458 Win. Mag./458 Lott. Bullet drop can be significant beyond 200 yards - if that's an issue - but these have the cross-sectional area to transmit a lot of shock even at lower impact speeds (~1800 fps) and heavy bullet weight for bone-busting deep penetration. The Ruger No.1 45-70 can be handloaded close to 458 WM ballistics.
Not on your list but consider
416 caliber. Bullet weights from 300 to 400gr. These shoot reasonably flat at high muzzle speeds, have sufficient cross-sectional area to transmit good shock and sufficient bullet weight for excellent penetration out to extended ranges.