7.62 mm, Ø grooves = 7.82 mm, land width = 4.47 mm and the primer type is large rifle. According to the official C.I.P. (Commission internationale permanente pour l'épreuve des armes à feu portatives) rulings, the .308 Winchester can handle up to Pmax piezo pressure. In C.I.P.-regulated countries, every rifle cartridge combo has to be proofed at 125% of this maximum C.I.P. pressure to certify for sale to consumers. This means that .308 Winchester chambered arms in C.I.P.-regulated countries are currently (2008) proof tested at PE piezo pressure. North American SAAMI maximum pressure for the .308 Winchester is . .308 Winchester vs. 7.62×51mm NATO Although originating from an identical preceding series of experimental cartridges, the commercial 1952 .308 Winchester and the military 1954 7.62×51mm NATO chamberings have evolved separately and are not identical. The .308 Winchester and military 7.62×51mm NATO cartridges are similar enough that they can be loaded into rifles chambered for the other round, but the .308 Winchester cartridges are typically loaded to higher pressures than 7.62×51mm NATO service cartridges. Even though the Sporting Arms and Ammunition Manufacturers' Institute (SAAMI) does not consider it unsafe to fire the commercial .308 Winchester rounds in weapons chambered for the military 7.62×51mm NATO round, there is significant discussion about compatible chambers and pressures between the two cartridges based on powder loads, chamber dimensions and wall thicknesses in the web area of the military compared to commercial cartridge cases. As the chambers differ, accordingly the head space gauges used for the two chamberings differ. Usage and performance The .308 Winchester is considered the standard hunting cartridge in the United States. It has gained popularity in many countries as an exceptional cartridge for game in the medium- to large-sized class. Although in North America it is commonly thought that it is only recommended for whitetail deer, pronghorn and the occasional caribou or black bear, the .308 Winchester is among the calibers recommended for hunting brown and grizzly bears by the Alaska Department of Game and Fish. Moreover, the Canadian Arctic Rangers chose the Colt Canada C19 in .308 Winchester/7.62×51mm NATO for "polar bear defense" in 2014; demonstrating that the .308 Winchester is suitable and even preferred for taking any medium, large or dangerous game located in the Americas. Clay Harvey, an American gun writer, said the .308 Winchester is usable on moose and elk. Layne Simpson, an American who has hunted in Sweden,