The .338 JDJ No. 2 will give good performance on african plains game, up through Elk size. It's recoil is a bit less than the .375JDJ, mostly due to lighter bullet weight. If your Contender was the pre- G2 version, you could also moderate recoil a bit with the use of Pachmayr Grippers and forend, for increased weight. The .35 Remington will work on elk at the distances you mention, but would not be my first choice. My preference in a single shot pistol for Africa has been the .375JDJ, because of its versatility.