Hunting and shooting are acquired skills. Big guns are a bit harder to shoot than littler ones. So you MUST practice with your rifle if you expect to any good with it. A .22 rimfire is good for basics and many rounds. A 30-06 is a very adequate big game cartridge, better to shoot one well than a bigger cartridge poorly. 375 H&H will require a bit more practice, doable for everyone, but the rifle is usually heavier by 1.5 lbs or so. A 375 Ruger is a 30-06 weight rifle, but kicks harder than the 375 H&H for that reason. I think though that if you can handle 375 H&H, you can learn to handle a 375 Ruger and benefit from a lighter rifle. In Ak, I'd carry a 375 Ruger. But it''s not necessary. A well-shot .30-06 with 200s or 220s is good enough. A .35 Whelen is a great cartridge, much power less recoil than the 375s or th 338s. The cartridges used for many, many years in Africa on the largest game have one thing in common: muzzle velocity about 2200 fps with a heavy bullet. So a 358 cal bullet at 2400 fps ought to be more than adeuqate for a big bear. And a 35 Whelen will shoot as flat as a 30-06 to 300 yrds with the same weight bullet. A 35 Whelen is a much overlooked cartridge of great potential with not too bad recoil. And you can load a 250g Speer HotCor to 2700 fps if you want (see Speer Rifle Data). The HotCor is a widely respected, tough bullet.