Scrumbag
AH elite
It is all about the bullet. If your rifle will accurately manage a tough 70 gr bullet, you would likely be fine for most of them. I have a South African friend who swears by solids from his .22 Hornet - of course that is a whole different level of velocity. A 55 gr bullet likely would be explosive on a blue duiker, suni, or dik dik. If the 55 stayed inside a common duiker or oribi for instance, all would be well. If it exited, you would be trying to salvage a shoulder mount. My little Sako shoots 55's beautifully. On coyotes, about a third exit. The exit wound is dramatic. Two out of three would not be a good hand with trophy fees involved.
I would agree bullet construction is very important.
Nosler make a 70gr Accubond that might work well and as I mentioned the 65gr Sierra Softs, 60gr Nosler Partition and the 62 gr Federal Fusion.
I think it is important to realise that for these small deer / antelope you cannot use "varmint" bullets. A light, fast driven varmint bullet does lots of damage on the entry side if you hit a solid bone like the shoulder - Might not even get into the chest cavity.
Scrummy