Only 12 cartrages. OK here is the Kachok list. A standard and long distance cartrage for each class of game covers all the bases + a few specility cartrages and their alternate second choices.
22LR or 22 Mag perfect little yard varmint gun.
223 Rem or 22-250 great long range varmint/yote rifle.
243 or 6mm Rem, great ballance of a long range varmiter and sissy kicking deer rifle.
6.5x55 or 260 Rem. Perfect deer class rifle for real world ranges without a doubt. Sissy kicking recoil and deadly performance, perfect beginers hunting rifle. Makes a fine medium range elk rifle too with its hefty 140gr-160gr javlins.
270 Win or 280 Rem a great all around gun for everything in the lower 48 and in many areas of Africa.
270 WSM or 7mm Rem Mag, for that cross cannyon shot on a trophy elk. I own both and perfer the WSM by a small margin.
30-30 or 35 Rem Simply perfect for an all around brush lever gun.
30-06 or 308 win I slightly perfer the 06 because the heavier bullets for larger game. 308 gets the nod if you like auto loaders.
300 Win mag or 300WSM Fill then nitch between the smaller and larger caliber quite nicley, shoots hella flat too.
338 Win Mag or 338 Lapua, all around North American Bad A$$ even at long ranges.
375 H&H or 375 Ruger. The go to gun for the plains of Africa. Also the minimum caliber for hunting largest and most agressive game in most African countries. Make a fine brown bear rifle too. Recoil is stout but nothing like the other large caliber. Trajectory is better then expected for a big bore gun.
And finnaly the 458 Lott or 460 Wby Mag. For the biggest, badest most agressive game on the planet, hurts more on the giving end then the receaving end, but you will live long enough to talk about how much it hurts
My friend owns a 460 and uses it as a practical joke getting people to shoot it, the last guy ended up on his butt about 6 feet from when he stood when he shot it.
You can flame me for ommiting such great calibers as the 25-06, 45-70, 416 Rigby, 7X57, 257 Roberts, 7-08, 35 Whelen and the 8mm Mauser, but they did not fill the nitches quite as well as the 12 I listed.