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The .358 Norma Magnum (.358 NM or 9.1x64mmBR) is a bolt action rifle cartridge introduced in 1959 by Swedish company, Norma. It is closely related to the smaller-bullet .308 Norma Magnum. Both calibers share the same dimensions of the case head as the .300 H&H Magnum, but have far less body taper, resulting in the same internal capacity in a shorter case.〔Kvale, Nils; ''Kulor, krut och älgar''. Norma, Åmotfors, 1963.〕 The cartridge case is the longest that will comfortably fit in a standard Mauser action, or any rifle action designed to chamber the 30/06. The .358 NM was the first .35 caliber cartridge commercially developed and sold to the American market since the decline of the .35 Newton in the late 1920s. ==Uses== Though introduced by a Swedish company, the .358 Norma was designed for American hunters, due to Norma's chief designer Nils Kvale's close contacts with American colleagues. It is a superb cartridge for the largest of North American game - elk, moose, brown bear, Bighorn Sheep, and bison, and shoots fast--and therefore flat--enough to be useful to 400 to 500 yards on game the size of American elk (Wapiti). While it is needlessly powerful for deer-sized game, it can be used, at least with the heavier (and therefore slower) .358 bullets on such game without destroying too much meat. It would work well, with properly designed bullets, on most large African species. But laws prohibiting the use of bullets smaller than on dangerous game, in most African countries, limit its use to "plains game," including the largest antelope, the one-ton eland. Norma took a gamble, introducing the .358 only as new empty cases for handloaders, and chambering-reamer specifications for gunsmiths who made custom rifles—there were no factory rifles available, and it was several months before factory-loaded ammunition appeared.〔Speer Reloading Manuals Nine through Thirteen.〕 But the cartridge proved immediately popular with hunters and custom gunsmiths, and within a year the Danish firm of Schultz & Larsen chambered its Model 65 for the round, and Husqvarna its Series 1600 and 1650 rifles.〔Cartridges Of The World, 6th and 8th editions, Frank C. Barnes.〕 Numerous American gunsmiths have made (and continue to make) custom conversions of suitable rifles, so numbers of factory rifles don't tell the full tale of the .358 Norma's popularity. The .358 Norma would be far more popular but for the .338 Winchester Magnum. Introduced in 1958,〔〔Lyman 47th Reloading Handbook, Hornady Handbook Of Cartridge Reloading, Fourth Edition.〕 the .338 Winchester was slow to take off, but has probably become the most popular medium-bore cartridge in the world, certainly in the U.S. The .358 is slightly more powerful, but the .338 is chambered by every American and most European gunmakers, and has the advantage of longer-for-diameter bullets with higher "sectional densities"--the bullet's weight in pounds divided by the square of its diameter, and so, essentially, pounds per square inch of frontal area-—than are currently available in .35 caliber. All else being equal, the higher the sectional density, the deeper the bullet will penetrate. Nonetheless the .338 Winchester, the .358 Norma, and the ballistically-similar .340 Weatherby Magnum are all excellent cartridges for anything smaller than Cape buffalo. But for those laws prohibiting sub-.375-caliber rifles on dangerous game, any of them would do anything the world-standard .375 H&H (Holland & Holland) Magnum will do. The .338 Winchester and .358 Norma are "short magnums," designed to work in "standard"--.30-06-length-—rifle actions; many 30/06 rifles over the years have been rebarreled to the much-more powerful .358 Norma. The .340 Weatherby and .375 H&H require longer, heavier "magnum" actions. Norma's factory ammunition for the .358 Norma drives a 250-grain bullet at 2880 fps, about as fast as the .30-06 can launch a 165 grain bullet. The .358 Norma produces more than 4,600 ft-lbs (foot-pounds) of kinetic energy at the muzzle, and can deliver a foot-ton 500 yards downrange. Its recoil is similar to that of the .338 Winchester and other medium bore magnum rifles driving similar weight bullets at similar velocities--punishing for the unpracticed, but masterable, even by smallish persons, and certainly far less than that of dangerous game (elephant) rifle cartridges. But for elk, moose, brown bear, kudu, eland, and the like, it is all the gun a hunter would ever need. The gun was referenced as the main rifle in the 1974 novel Deathwatch. The handloader can easily make cartridge cases by necking up and fire-forming cases from any similar,.532-inch base diameter, belted magnum: the .338 Winchester Magnum, .308 Norma, etc., or by shortening and forming longer belted magnums. Norma continues to make factory cartridge cases in this caliber. One advantage many handloaders enjoy is that the bore, being .358-inch, allows use of the vast variety of relatively inexpensive bullets designed for the popular .38 Special/.357 Magnum handgun cartridges to be used for plinking, hunting small game and vermin, and lower-recoil target practice. Light (lower power) loads with bullets designed to expand at lower velocities, that emulate lesser cartridges such as the .35 Remington or .358 Winchester, can also be handloaded for use on deer and other smaller big game, something that cannot be done with the .338's and .375's for lack of suitable bullets. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「.358 Norma Magnum」の詳細全文を読む スポンサード リンク
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