.300 H&H: The First .30-Caliber Magnum
May 02, 2017
The .300 H&H Magnum, sometimes referred to as Holland's Super .30, was introduced in 1925 by the British firm Holland & Holland and was the first of many offspring to be spawned by the earlier .375 H&H Magnum.
At the time of the .375's introduction, Holland & Holland was building rifles on turnbolt actions from the Mauser factory in Oberndorf, Germany, and while experimenting with cartridge cases of various shapes, it was concluded that considerable body taper topped them all for smooth feeding from magazine to chamber.
It was also believed that plenty of taper made a fired case easier to extract from a dirty chamber. Both factors were considered important in a rifle/cartridge combination designed for use on potentially dangerous game.
Giving the body of the rimless .375 H&H case plenty of taper left very little surface area on its 15-degree shoulder for headspacing, so it was given the belt of the .400/375 Belted Nitro Express, introduced by Holland & Holland in 1905.
The .300 H&H is a direct descendant of the .375 H&H, but the shapes of their cases differ considerably. Whether by design or accident has been lost in time, but an even smoother-feeding cartridge resulted by combining the sharply tapered body of the .375 H&H case with an extremely long and tapered shoulder with an angle of 8 degrees, 30 minutes.
And it paid off, too. In a fine-tuned action, the .300 H&H glides from magazine to chamber like grease on glass.
The two H&H cartridges became immediate hits among well-heeled sportsmen who traveled far, but the price of English-built rifles was beyond reach of the workingman.
A best quality Magazine Rifle on the Mauser action sold for 35 guineas in London and $320 in New York. The American firm Griffin & Howe began offering custom rifles chambered for both cartridges around 1926, but they also were quite expensive when compared to factory-built bolt actions like the Winchester Model 54 and Remington Model 30 available at the time.
The British originally loaded the .300 H&H with cordite, a propellant formed into long strands resembling spaghetti. The strands were usually long enough to reach from the base of the cartridge case to the beginning of its shoulder.
Linen string was often used to tie a number of strands into a bundle prior to being placed inside the case. And since that made insertion into a necked-down case impossible, the bundle was inserted prior to that operation.
Due to its extremely high nitroglycerin content, cordite was quite erosive on barrels. It was also subject to wide fluctuations in pressure when subjected to extremes in ambient temperature.
Realizing the .300 H&H would be used in tropical climates, the British down-loaded the cartridge to about the same performance level as that of the .30-06 as it was loaded in the United States.
Advertised velocities for 150-, 180-, and 200-grain bullets were 3,000, 2,700, and 2,350 fps respectively.
Soon after the .300 H&H arrived in America, Western Cartridge Co. gave it a big kick in the pants by increasing chamber pressure, which was made possible by the use of more stable powders.
Two loadings were introduced: a 180-grain load at 3,060 fps and a 220-grain load at 2,730 fps, both measured from a 24-inch barrel. Velocity of the 180-grain load was said to exceed 3,100 fps in a 26-inch barrel. At the time .30-06 factory ammo loaded with a 180-grain bullet was rated at 2,690 fps from a 24-inch barrel.
Many of the custom rifles in .300 H&H built by Griffin & Howe during the 1920s and 1930s were on 1917 Enfield actions, and that included the heavy-barrel target rifle Ben Comfort used to win the 20-shot, 1,000-yard Wimbledon Cup match at Camp Perry in 1935.
Popularity of the .300 H&H among long-distance target shooters actually began during the late 1920s, and by the time Comfort got around to giving it a try, American manufacturers were offering match-grade ammunition. He won the match with Western ammo loaded with a 180-grain full metal jacket bullet of boattail form.
Comfort's win at Camp Perry got the attention of the paper-punching crowd, and while many hunters were aware of the cartridge, its lack of availability in more affordable rifles kept it from becoming equally successful as a big-game cartridge.
That began to change in 1937 with the introduction of the Winchester Model 70. Just as important as its availability was its price. The standard-grade rifle had a 26-inch barrel and sold for $61.25. Even when the price of a scope and mount was added, cost of the Model 70 was only about a third as much as an imported rifle in .300 H&H Magnum.
To capitalize on the success of the .300 H&H in competitive shooting, Winchester also offered several target versions of the Model 70. All were considerably less expensive than the Griffin & Howe rifle used by Comfort, yet accuracy was reputed to be as good and sometimes better.
The National Match Rifle with standard-weight barrel weighed 9.5 pounds. The heavier barrel of the Target Model Rifle increased its weight to 10.5 pounds. Adding even more weight to the barrel resulted in the Bull Gun at 13.25 pounds.
Sad to say, no standard-production rifle I am aware of today is available in .300 H&H Magnum, and collectors have put the old Model 70 beyond reach of many riflemen. During the 1960s Colt offered the Coltsman on an FN Mauser action, and most of those are probably also gathering dust in collections.
Back when Browning rifles were built around FN Mauser actions I bought one in .375 H&H and first used it on a hunt for Cape buffalo and other African game. The previous owner of that rifle also had one in .300 H&H, and I should have bought it as well.
Remington did a limited run of Model 700 Classics back in 1983, but good luck finding one. A few Ruger No. 1s have been chambered for it. Today, a vintage Remington Model 721 is usually the most affordable, but even it is becoming scarce.
My first rifle in .300 H&H, a custom job built on the 1917 Enfield action, was not very accurate. But the Winchester Model 70 I hunted with for several years (and should have kept) had a 26-inch barrel and was one of the first rifles I owned that shot inside minute of angle.
It happily took a couple grains more of H4831 than what was listed as maximum by Hodgdon, and according to my Oehler Model 10 chronograph, a 180-grain bullet exited its 26-inch barrel with an average muzzle velocity of 3,112 fps for a duplication of the original Western Cartridge factory load.
I don't recall discarding a single case due to an expanded primer pocket. A Model 70 Bull Gun in .300 H&H I shot for several years was even more accurate.
My all-time favorite rifle in .300 H&H was built a few years back by Lex Webernick of Rifles Inc. of Pleasanton, Texas. After blueprinting a Remington Model 700 action, he fitted one of Dan Lilja's match-grade, 26-inch, stainless-steel barrels with three-groove rifling at a twist rate of 1:10 inches.
The rifle's laminated stock consists of two layers of carbon fiber sandwiched between three layers of fancy walnut, and it is a beauty. Unfortunately, the maker of the stock is no longer in business. Webernick also replaced the factory aluminum trigger guard-floorplate assembly with an all-steel version from Brownells.
A test group accompanying the rifle, shot at 100 yards on Webernick's test range, measured just under a half-inch.
Remington and Winchester no longer load the .300 H&H, but Hornady, Federal, and Nosler do. And for those who wish to turn the calendar back to the 1920s, Kynoch offers the 180-grain Woodleigh Weldcore bullet at 2,700 fps.
Handloading Holland's Super .30
With unprimed cases available from Hornady and Nosler, the .300 H&H is an excellent candidate for handloading. For many years IMR 4350 was the favorite of many handloaders, and while still quite good, it now has plenty of competition.
Some of the highest velocities from my rifle are compliments of IMR 4955. Accuracy leaves nothing to be desired, and due to low velocity spreads when subjected to extremes in ambient temperature, it has become my first choice for big-game loads.
Data in some of the old reloading manuals pushed 180-grain bullets to 3,100 fps, and while some of today's manuals approach that velocity, others don't. For example, Hodgdon's Annual Manual has close to the same maximum speeds for the .300 H&H and the .300 Winchester Magnum, both in 24-inch barrels.
The same goes for the Lyman manual, except the .300 H&H test barrel was 2 inches longer than for the .300 Win. Mag. The Sierra manual gives the Winchester cartridge a 200 fps edge, while the Nosler manual has the Winchester cartridge 137 fps faster. Cartridges such as the .45-70 and .44-40 Winchester are loaded light out of respect for old rifles and those of fairly weak design.
Neither applies to various factory rifles that have been available in .300 H&H through the years, yet some sources seem to be loading it below its true potential.
SAAMI maximum chamber pressure for the .300 H&H is 54,000 Copper Units of Pressure (CUP). There is no conversion factor for CUP to pounds per square inch, but if there was, Ron Reiber at Hodgdon Powders says it would be around 65,000 psi.
That has to be close because in Europe, the CIP (the equivalent of our SAAMI) has maximum chamber pressure at 62,000 psi. Considering that the .300 H&H has generally been available only in rifles with extremely strong actions, loading it to considerably lower chamber pressures makes no sense.
It makes even less sense when we consider that the .300 Win. Mag. case is no stronger than the .300 H&H case, yet SAAMI maximum for it is 64,000 psi.
Case capacity is in favor of the .300 Win. Mag., but it's not by much. Water capacity of the Hornady .300 H&H Magnum case is only one grain less than for the .300 Win. Mag. case, and for cases of that size, such a minor difference in capacity has an insignificant bearing on chamber pressure and velocity.
Capacity of the Hornady case is 7.0 grains greater than for .300 WSM brass made by Winchester. Everything, including barrel lengths and the pressure to which the three cartridges are loaded, being equal, velocity of the .300 H&H would be the same as for the .300 Win. Mag. and higher than for the .300 WSM.
Hunting with the .300 H&H
Through the years I have bagged a few head of big game with various rifles in .300 H&H. One of the finest was a mountain caribou taken in the Yukon. My rifle was a 1940s-vintage Winchester Model 70 wearing a Zeiss Diavari ZA 1.5-6X scope. When loaded with the right bullet, the old-timer is capable of cleanly taking anything in North America.
The hunter who goes after pronghorn antelope does not need its power, but when loaded with the Barnes 130-grain TSX BT at 3,400 fps, it shoots flat and delivers a deadly blow at great distances.
Moving to the opposite extreme, there are better choices in cartridges for use on brown bear, but I would not hesitate to take on one with a rifle in .300 H&H using ammo loaded with the Swift 200-grain A-Frame at 2,850 fps. For everything else in between, 180-grain bullets, such as the Sierra GameKing and Hornady InterBond, are good choices.
The popularity of the .300 H&H began to decline with the importation of millions of military-surplus rifles beginning in the 1950s and continuing for about the following three decades.
Actions of standard length, such as the Winchester Model 70 and Remington Model 721, were capable of handling the old cartridge, but gunsmiths across the country were building thousands of rifles on cheap 1903 Springfield and 1898 Mauser actions, and both were too short. This led to the development of shorter wildcats on the H&H case by P.O. Ackley and others.
Then came the .308 Norma Magnum. On one of the several visits I made to the Norma factory through the years, I discussed the development of the .308 Norma Magnum with an old-timer who was quite familiar with the cartridge.
I learned the cartridge was designed specifically to deliver .300 H&H velocity with a case short enough to work in the Mauser and '03 Springfield actions. The task was to come as close as possible to duplicating the capacity of the Winchester .300 H&H case.
They did a darned good job. I still have a few .308 Norma cases as well as a box of Winchester .300 H&H cases, both made during the 1950s; when filled to the brim with water, the .300 H&H case holds a mere half-grain more.
The Norma cartridge represented the first blow, but the introduction of the .300 Win. Mag. is what finally crowded the grand old British cartridge away from the trough. Even so, if you already have a rifle in .300 H&H, you don't need a .300 Win. Mag.
On the other hand, if you have neither, there is no logical reason to choose the British cartridge over the Winchester cartridge unless, like me, you pull for the underdog and are sentimental enough to have a custom rifle in .300 H&H built.