Have spent considerable time in Africa with a number of PH's, and have spent considerable time talking with them. (There were at least 6 on a month-long cull hunt in 2007.) One of the questions I always ask is what they advise for plains-game clients--and what rifles they load/rent, of any. The .30-06 and 7mm Remington Magnum have been the only chamberings I recall in rental/loan rifles, and the .375 H&H for dangerous game.
However, Finn Aagaard usually rented a .270 Winchester for clients who didn't bring their own "light" rifles. His estimate, of I recall correctly, is that only about a third of his clients could shoot any .300 magnum to be effective on plains game.
John,
My limited experience (3 trips) yielded pretty much the same answers you received. My first PH had .308, 30-06 and .22 hornet as his main rental rifles. The second PH had a 7mm-08, and a 300WM (suppressed) for rental. Both had .375 H&H for the big stuff.
From what I've seen/read in the past few years is that now nearly every outfitter's rifle has suppressors for a variety of reasons - easy recoil for all shooters no matter the size of cartridge, along with the reduction of noise in spooking game.
