Those two rifle calibers are on two ends of the spectrum.  If it was me I would go with the .375 Ruger.  The big reason is that the .375 can do more than the .30-06 as far as the legality of using it to hunt African game animals.  Now if you have the money then by all means get both.  A man can't have enough rifles. 

First of all, welcome to the site!  Make sure you stick around, browse the forums, and take in alot of the posts.  There is tons of information on here!

As for you question, as Critter said, a man can never have enough rifles.  Go with both, unless you are limited by budget.  I would say, if you are only able to get one, then gotwitht he 375.  Can't go wrong with that, and even though I have never hunted African game, I could see it being more versatile.

Best of luck on your future safaris, and make sure to throw up some photos of past and future hunts.  We'd love to see them.

I would go with the .375 Ruger as well and have been eyeing them up quite a bit lately. Ruger does make the left hand model but otherwise you can get a Howa right handed barrelled action and an aftermarket laminated stock for a much better price. Not a big help for you but the direction I've been looking. I have no need for one just have gotten the itch for something different.

One thing you might want to look at is the availability of ammo in various corners of the world.

The .375 H&H has been around a long time while the .375 Ruger is a youngster. I know for a fact I can get .375 H&H in Sydney, Australia along with Alaska, and South Africa. That alone makes me opt for the older cartridge over the youngster on the chance I may become seperated from my luggage through international travel.

I have had friends seperated from their rifles due to being lost in transit and others seperated from their luggage containing their ammo but their rifles arrived at the right destination. As good as the 375 Ruger may look, or what it does better than the round that came before it, is negated if you can't find ammo for your pill luancher.

Biker

I'm afraid that as close as I'm ever gonna get to Africa is right here. Always wanted to but it ain't gonna happen. I have dreamed for a long time about it and what would I take. I think that if could only take one rifle, and hunting the game you talked about, I'd take a 338 Win Mag. I have little use for magnum cartridges any more but the thought of Africa steps up the game quite a bit. If I were taking two and animals like Elephant, Water Buff, ect were on the ticket, I'd step up to the 375 H&H. As was said earlier, you can get them anywhere over there. I think it is the min calibre for animals such as Buff and Elephant. And a cartridge like either the 338 Win Mag and 375 H&H would certainly do well in North America up to and including Alaskan Brown bear.

A couple guy's said you can't have to many gun's. I've always felt the same but at this point in my life I realize that had I better thought out the rifle's I wanted and avoided the rest, I could have had a safari on the money I spent on the rifles alone, most of which have since changed hand's. If money wasn't a porblem for me well, I really could use a few more rifles but I really need a few really nice SxS's! At this point in my life, if I went, I would only take photographs. Nothing holds my attention better than a bunch of Africa photo's, the land and the animals are magnificent!

Have a great trip and bring back a lot of photo's!

If your hunting plains game only, might I suggest the rifle you already have is more than enough for any plains game even Eland, you could take the money you planned on using for a second gun and add 1-2 more trophies on your trip. My other suggestion would be to insure you study the shot placement book for african animals as they are located sllightly different than north american game. Spend a little time on a daily basis keeping a jornal of everydays event, great way to keep those memories. Good luck!!!!