I'm probably in the minority but I feel a .270 is too light for larger plainsgame (oryx, hartebeest, etc.) I know most folks say it'll get the job done w/practice & more practice & very good shot placement...but none of us make a "very good shot" on EACH & EVERY trigger squeeze. There are scores of fat buzzards & hyenas attesting to this...I feel strongly that Bigger is Better ( w/in the shooter's capabilities...)
Case in point; On our 1st plainsgame hunt my wife & I were offered 2 nice rifles to use, a Weatherby .30/'06 & a Brno .375 H&H, both with ammo appropriate for large animals And each had the same scope ("Lynx" RSA-made, I think)...we fired mult. shots w/each @ paper---right on @ 100 meters, both. We both started w/the '06 and required more than 1 shot to kill an oryx & a hartebeest. Switching to the .375, a zebra, giraffe, blue wildebeest, & another hatebeest (culled b/c it was sick) dropped dead @ 1 shot...all shots were about 120 yds or less...Coincidence? Maybe...but if i were a deer and had to be hit by a vehicle (weird scenario, I know), I'd rather be run over by a bus than a VW bug...
One last note...check out the Official Regs. for several African Countries... a few, if I read correctly, require .30 cal or 7mm for kudu sized game...