The history of commercial .30-caliber magnum cartridges developed prior to the .300 Winchester is noteworthy and helps explain the design features of that cartridge. The .30 Newton, developed in 1913 and based on the German 11.2x72 Schuler case, is generally considered the first .30 caliber with magnum type performance, but its success was limited. The .300 Holland & Holland (H&H) Magnum appeared in 1925 (known then as the Super-Thirty) and was based on the .375 H&H Magnum belted case.
There are minor technical variances between the .300 H&H and the .30 Super Belted Rimless H&H cartridges, but they are not pertinent here. However, it should be noted that .300 H&H ammunition should not be fired in a .30 Super rifle, but the latter can be fired in the former.
Due to the long sloping case, the belt was necessary to provide positive headspace control. Like the .375 H&H, the .300 H&H had an overall length of around 3.600 inches and could not be housed in most .30-06 length actions. The .300 remained somewhat exotic to U.S. shooters; however, in 1935 Ben Comfort won the prestigious 1,000-yard Wimbledon Cup with a custom rifle so chambered. As a result, its fame soared and within months Winchester announced the brand new Model 70 rifle along with that caliber as a standard offering and began producing ammunition domestically.
The .300 H&H became widely popular in the U.S. and established a superb reputation as a general purpose big-game cartridge. During World War II, Roy Weatherby sought to improve its ballistics and blew the case out to significantly increase the powder capacity, which became the .300 Weatherby Magnum. Like the H&H, the Weatherby cartridge required a long, 3.600-inch magnum action.
With a booming post-war economy, during the 1950s Winchester began developing new cartridges such as the .458 Winchester Magnum in 1956 and the .264 and .338 Winchester Magnums in 1958. Each of the above cartridges is based on the .300/.375 H&H belted case, shortened to function in a standard length (3.340-inch) .30-06 action. By comparison, they were “short action” magnums. It is important to note that the belted magnum case was chosen because it offered the powder capacity to reach the desired performance, but also because Winchester was already making cases and retooling would have been costly. Incidentally, the .458 is more or less a straight case and needed the belt for proper headspace control; however, the .264 and .338 feature a 25-degree shoulder for positive headspace and the belt was not necessary. Since Winchester was already manufacturing the belted magnum case, it was the logical choice to develop new cartridges during that era.
There was an obvious void in the new Winchester magnum cartridge lineup, as it lacked a .30 caliber, which has been popular with U.S. shooters and hunters since the 1890s. Almost all shooters anticipated a new .30 caliber from Winchester, but when that didn’t happen immediately, they necked the .338 Winchester down to create the .30-338 wildcat. Norma recognized the value and widespread appeal of a .30-06 length, .30-caliber belted magnum and introduced the .308 Norma in 1960 and even “loaned” reamers to gunsmiths wanting to convert an existing .30-06 rifle to .308 Norma. Although very similar to the .30338 wildcat, the .308 Norma offered slightly greater powder capacity. Both of the above cartridges became relatively popular, but that was short lived.
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OEHLER's New System 89 Chronograph
Measuring Bullet Performance Downrange
The Problem with Low Pressure Loads
Bullets & Brass
Measurements for Rifle Handloading
Handy Techniques for Accurate Ammunition
THE BRASS RING
Semi-custom Bullet Moulds
Mike's Shoot in' Shack
REVISITING THE 6.5 -06 A-SQUARE
Loading New Bullets and Powders
Cimarron Stainless Frontier .45 Colt
From the Hip
MONTANA VINTAGE ARMS HIGH WALL
THE HEART OF THE SINGLE SHOT
CIMARRON MODEL 1894 .38-55
ROCK RIVER ARMS AR-10
Loads for a .243 Winchester
The 6mm Creedmoor was designed for long-range target shooting with long and skinny, heavy-for-caliber bullets that slip through the air with the greatest of ease. Wind affects these bullets little; they just fly right through it, almost unaffected.
The idea was simple enough: Friend Cole Bender from PROOF Research offered to rebarrel my Winchester Model 770 .243 Winchester, a rifle I hadn’t shot in years. When returned, I would have a heavy-barreled .243 Winchester to replace my beloved Remington 700 BDL Varminter that was sold to pay some emergency debt long ago forgotten. I can say this rebarreled 770 will never replace that old Remington, but it has the potential to do some very useful things in the field.
RESTORING OIL FINISHED STOCKS
The Reinvented .45-70 Government
MOSTLY LONG GUNS
Winchester's New 6.8 Western
Not Your Father’s “.270”
Half a Century With Model 700s