Big Magnums not needed. Yes, I would buy one in .338 Win Mag, but non of the others. They currently make a very good selection, that will handle everything in North America. Let's face it, the bulk of Handi owners aren't the type to be going off to Africa. The only thing I can think of that might be an area not currently covered would be a .17 Fireball. .17 Remington would shoot out barrels too fast, but a Fireball can do the same thing and a lot less errosion to the throate.
I keep seeing .375 H&H. Think about it for a minute, there must be a reason Alaskans have moved away from that old round. Recoil is tremendous for no more velocity than it puts out (2565fps). .35 Whelen can come very close to matching it without the tremendous recoil, and a much flatter trajectory. Trajectory on the .375H&H is like a rainbow, they are no good beyond 300 yards. Maximum effective range is 245 yards. The 300gr bullet that leaves the Muzzle at 2565fps bleeds off real fast, (as do the other bullets as well) that same bullet is only going 2000 fps at 245 yards. Energy has gone from 4382ft lb at muzzle down to 2664ft lb at 245 yards, and it continues to bled off real fast.