.375 H&H Magnum
Date: Apr 17 2020
Few cartridges have become so universally accepted among hunters as the .375 H&H Magnum, often considered the best single choice if limited to one caliber for hunting all game the world over. It has earned a superb reputation for taking heavy African game, including elephant, buffalo, lion, etc., but it is also widely popular in the North for hunting moose and especially the great bears. Originally developed in 1912 by the English gunmaking firm Holland & Holland, it featured a long tapered case with a minimal shoulder, and thus received a belt for positive headspace control. This case would become the “parent” for many other Magnum cartridge developments, especially in the U.S.
Being primarily a hunting cartridge, wherein handloads must chamber easily, full-length sizing is suggested.
In order to obtain reliable ignition under a variety of temperatures and due to the large powder charges, Large Rifle Magnum primers are recommended with Winchester primers being used herein.
Bullets should be crimped in place, which usually works best if performed as a separate step. If using a roll crimp, cases must be of uniform length. The Lee Precision factory crimp die is another option that is less sensitive to small variance in case length, while still allowing a heavy crimp.
Early Cordite loads featured 235-, 270- and 300-grain bullets at 2,800, 2,650 and 2,500 fps, respectively; however, today’s ballistics (as loaded in the U.S.) advertise a 270-grain bullet at 2,690 fps or a 300-grain at 2,530 fps. Using 270-grain Hornady SP-RP bullets, those speeds were easily duplicated using IMR-4064, Alliant Reloder 15 and Hodgdon Varget powders. Switching to 300-grain bullets, Hodgdon H-4895, Varget, IMR-4064, Alliant Reloder 15, Vihtavuori N-140 and Winchester 760 either duplicated or slightly exceeded factory load performance.
The maximum average pressure limit for the .375 H&H Magnum is established at 62,000 psi, and none of the accompanying data exceeds that figure.