Jeff now shifted to a William Evans boxlock ejector in .500 Nitro Express because field experience has taught him that the 570Gr bullet at 2150 FPS (of the .500 Nitro Express) will out-penetrate the 750Gr bullet at 2050 FPS (of the .577 Nitro Express). He also recently purchased a pre-World War II Holland & Holland Royale sidelock ejector in .500 Nitro Express and will be using that in Botswana for the coming season (along with his .505 Gibbs which was built by John Boliger for him on a left handed Granite Mountain Arms African Magnum Mauser action).
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Jeff's rifles for the coming season
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The Holland & Holland Royal sidelock ejector .500 Nitro Express (Holland & Holland is Jeff's favorite double rifle brand above all others)
To answer the original poster's question, in all practical terms ... A .500 Nitro Express/.500 Jeffery/.505 Gibbs/.500 A Square is the largest practical size of caliber which most hunters (even white hunters) are capable of properly handling.
That said, calibers like .577 or .600 Nitro Express are not meant to be 100 % practical. They're food for the soul for certain crazed & irrational dare devils (such as myself). And for those who learn to counteract the recoil... these calibers prove their worth when it comes to stopping large & dangerous inbound creatures when it's a matter of life or death. Of course, you still have to land a shot in the proper region in order to ensure success (which is generally difficult for a many but the most stubborn of hunters with these calibers).
Personally speaking, the .600 Nitro Express is a dream caliber of mine. I have only hunted with this caliber on one occasion till now- A hippopotamus bull on land with a .600 Nitro Express Heym Jumbo sidelock ejector. Ammunition was Labor Fur Ballistik 900Gr tombac jacketed FMJ solid factory loads.
Was it effective ? I'll let you all decide.
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50 years of shooting hippopotamus on land with .375 Holland & Holland Magnums (and a couple with .404 Jeffery and .458 Winchester Magnum)... has never allowed me to see this level of ballistic terminal effect on a hippopotamus with any other caliber. Someday, that Heym Jumbo is going to be mine.
My friend, white hunter Mark Sullivan recently purchased this beautiful Charles Osborne back action hammer .600 Nitro Express (built in 1911) and hopes to use it in Tanzania the coming season.
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