The Germans built a 51cal bolt action rifle in WW1, basically an overgrown Mauser, that weighed 70 pounds. Course it was an anti tank weapon, firing 13x92mm rounds with a 965 grain bullet, 2.2 ounces for ye not familiar with that system, with a steel core that would punch through 22mm of armor at 100 yards. I think that should drop most big game.Nathan F wrote: 'Elephant Guns' is a colloquial term to describe any large caliber 'magnum' round, such as the .455 H&H Magnum, .416 Rigby Magnum, and .458 Winchester Magnum. These guns are usually found in double barrel form to allow for a quick follow up shot. A few bolt rifles have been made, but, it takes a hefty bolt to be able to stand up to that kind of artillery.
And the whole thing was only a interim measure until an overgrown 13mm Maxim gun called the Tank und Flieger or TuF could be produced to kill Allied tanks. Unfortunately, for the Germans, only a limited number of rifles and a few dozen of the machine guns where completed before the Armistice. It was this machine gun that caused the US Army to ask Browning for a fifty cal weapon, and that gave us the M2..
But that history lesson is a bit later along then most of the "classic" elephant guns.