When I lived there people whacked them with a .30-06 regularly. So I would say anything in that class on up. Pinotguy's suggestion of the .35 Whelen & 9.62 are good. But if it was me I would take a .375 H&H, simply because I like it. You can get by pretty well with diligent maintenance on your rifle. Make sure the action & barrel channel are glass bedded. You can free float the barrel but leave enough glass so that the barrel channel is protected. Keep the action, barrel and even the stock wiped down (I like WD-40) and you should be good to go even with blued steel & a walnut stock. Take a cleaning kit with you to keep the bore clean. Other than that, take what ever make & model that trips your trigger.