Hi
what is your favourite gun and caliber for hunting in south america?
regards
yes

9,3x62

L

Would a .358 Win be preferred over a .30-06, .300 mag or would a .338 be best?

I am sure that Lorenzo knows far better than I, but his choice of caliber is not one readily used in the US. Of the ones you mentioned, if the choice was mine I would go with the .300 Win Mag. or the 30-06.

We all have a cartridge of our preference ... mine is the 375H&H and in a second close place the 45/70 ... but from a practical point of view (mainly considering ammo availability down here) the 308 win is ahead of them all (and my close third in preference )

Like Martin said, the 308 is the most practical caliber to be had here due to ammo availability. Of course, the 375 H&H or the 300 WM are much better for certain very specifical purposes, like shooting water buff or deer in the mountains. The 30-06 is not widely found and everything that the 30-06 does so does the 308 or our own old 7.65x53 Mauser.