.358 Norma Magnum

Infobox Firearm Cartridge
name= .358 Norma Magnum


caption=
origin= Sweden
type= Rifle
designer= Nils Kvale
design_date=1950's
manufacturer=Norma
production_date=1959
number=
variants=
is_SI_specs=
parent=
case_type=Belted rimless, bottleneck
bullet=.359 (9.12)
neck=.388 (9.45)
shoulder=.490 (12.45)
base=.513 in (13.03 mm)
rim_dia=.531 in (13.5 mm)
rim_thick=
case_length=2.520 (64.0)
length=3.346 (85)
rifling=
primer=Large rifle magnum
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The .358 Norma Magnum (.358 NM or 9.1x64mmBR) is a rifle cartridge introduced in 1959 by Swedish company, Norma. It is closely related to the smaller .308 Norma Magnum. Both calibers share the same dimensions of the case head as the .300 H&H Magnum. [Kvale, Nils; Kulor, krut och älgar. Norma, Åmotfors, 1963.] The length of the case is the longest possible that would comfortably fit in a standard Mauser action. 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 1920's. [.358 Norma Magnum, The Reload Bench. Accessed on 9-20-2007. [http://www.reloadbench.com/cartridges/358nm.html] ]

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, and bison. 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 .375-inch on dangerous game, in most African countries, limit its use to "plains game," including the largest antelope, 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, [Cartridges Of The World, 6th and 8th editions, Frank C. Barnes.] [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 bullets with higher "sectional density"--the bullet's weight in pounds divided by the square of its diameter, so, essentially, pounds per square inch of frontal area--than are available in .35 caliber. All else being equal, the higher the sectional density, the deeper the bullet will penetrate. Nonetheless the .338, 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; factory rifles in .35 Whelen are easily rechambered to the much-more powerful .358 Norma. The .340 Weatherby and .375 H&H require longer, heavier "magnum" actions. Handloaded to its full potential, the .358 Norma can drive a 250-grain bullet (there are 7,000 grains to the pound, 437.5 to the ounce) to 2880 f/s (feet per second), a little less than 2,000 miles per hour (2933 f/s), about as fast as the .30-06 can launch a 150-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. It produces recoil to match: even in a rifle weighing 10.5 lbs with scope and sling, the recoil of a .358 Norma is everything most seasoned shooters will care to tolerate. But for elk, moose, bear, kudu, eland, and the like, it is all the gun most hunters would ever need.

The handloader can easily make cases by necking up and fireforming .338 Winchester Magnum cases.

References

[http://www.norma.cc/content.asp?Typ=59&Lang=2&DocumentID=301&Submeny=4&Rubrik=Calibers&Title=358%20Norma%20Magnum Norma]