Bell's favorite elephant rifle was his custom 1903 Mannlicher-Schoenauer 6.5x54, which he plainly states somewhere in one of his books, but he gave it up because problems with the ammo, mostly split cases.
"Use Enough Gun" comes from a Ruark quote of Harry Selby, not Taylor.
A good friend's wife took her first three big game animals last year in Africa with a .243. Kudu wasn't on the list, and her first was an impala, but gemsbok and blue wildebeest (both generally considered tougher than kudu) also each fell to one 85-grain Nosler Partition.
“Montana seems to me to be what a small boy would think Texas is like from hearing Texans.” John Steinbeck
