I am not goin to go out and buy one of these any time soon. But I want a dangerous game type of bolt gun eventually. Just for fun. What are thought on these two calibers pro's and cons.

Dangerous game? The 375 of course

Ya, I doubt I will ever get to hunt in africa though. Its just another toy I want some day.

The ballistics of these rounds are pretty well-known; there's not something one will do but the other won't. It's really a choice of SD vs MV and the like. E.g., the STA will shoot 270's a bit slower than the 375 Wby, but the .358" 270 has a better SD. The .358" has a wide range of bullets available, including some cheap pistol pills for plinking. If you aren't going somewhere that has a .375" minimum bore restriction (Africa) then it really just doesn't matter. They really are peas in a pod.

naja302 ----- If you want to hunt dangerous game in North America, either chambering will serve you well. Dangerous game in Africa require .375 minimum in most countries, however in the field your PH is the boss. Checking the manuals you will find in the Nosler fifth edition and the Barnes third edition the information to compare. The largest bullet listed in both books for the STA are 250 grains because that is the largest bullet made by these manufactures. I will give my speeds for the 270 and 280 grain bullets for comparison. Realize a reloader can surpass those book figures considerably for both .358 STA and .375 Wby. I shoot two STA's, one is 50 to 150 fps faster than the other consistently. My fast rifle will throw a 270 grain North Fork or 280 grain Swift A-Frame 3000 fps plus with MOA and with pin point accuracy averaging 2900 to 2950 fps. The speeds given here are chronographed on an Oehler 35P chronograph. These speeds compare with the .378 Wby and .375 Rem Ultra mag. As Bwana-be stated the SD of the .358 caliber bullet is better than that of the .375 caliber bullet, normaly considered to give better penetration. Some say faster speeds do not give more penetration, but most agree that the better SD does. Doing your own tests with your loads only will tell you what you need to know in that department. ----- Pick your poison, they are both great chamberings. I take my STA's to Colorado and Alaska regularly with excellent results. I took my .358 STA to Africa for plains game and a .416 Rem for dangerous game and they served me well. Truth be known I don't go anywhere without one of my STA's. Good luck and good shooting.