The .244 H&H Magnum and .240 Apex
By Chuck Hawks
The famous British firm of Holland & Holland has long evidenced interest in 6mm (.24 caliber) rifles and ammunition for sporting purposes. In this the British were well ahead of U.S. arms and ammunition makers. Two of the most notable British .24 caliber cartridges, both belted magnums, were designed by the prestigious London firm of Holland & Holland.
The .244 H&H Magnum
The .244 H&H Magnum was introduced in 1955. It could be considered the final word in 6mm cartridges. As factory loaded it exceeds the muzzle velocity (MV) of the .240 Weatherby Magnum, not introduced until 1968, by about 100 fps. Loaded to the same pressure with modern powders it would beat the hot Weatherby Magnum by more, as it has a longer and fatter case of considerably greater capacity.
The other modern 6mm magnum, the .243 WSSM of 2003 (which is merely a ballistic twin of the 6mm Remington) pales in comparison to real magnums like the .240 Weatherby and .244 Holland & Holland. (See my article "Compared: The .243 WSSM and .240 Weatherby Magnum.")
1955 was also the year the .243 Winchester and .244 Remington (later renamed the 6mm Remington) were introduced. Both the .243 and 6mm Remington are fine, well balanced cartridges and fortunately neither claimed to offer magnum performance, because the .244 H&H blows their sox off.
The .244 is based on the full length .375 Magnum case with less body taper and a shortened neck. The rim diameter is the usual .532" of magnum cartridges. The base diameter just forward of the belt is .508" and the shoulder diameter is .445". The case length is 2.78" and the cartridge overall length (COL) is 3.58". Bullet diameter is .243-.244", and large rifle magnum primers are required.
The British factory ballistics called for a 100 grain bullet at a MV of 3500 fps and muzzle energy (ME) of 2725 ft. lbs. This was achieved by some 74 grains of an unspecified smokeless powder (not Cordite). At 200 yards the remaining velocity was 2970 fps and the kinetic energy 1980 ft. lbs.
I do not know the ballistic coefficient of the British bullet, but the trajectory of that load using a 100 grain Speer Grand Slam bullet (BC .351) would look like this: +2.3" at 100 yards, +3" at 165 yards, +2.7" at 200 yards, and -3" at 330 yards. The maximum point blank range (+/- 3") would thus be 330 yards, putting the .244 H&H Mag. near the top of ultra-long range cartridges.
There is always a price to be paid for that kind of performance, and in the case of the .244 Magnum that meant excessive recoil and muzzle blast for a .24 caliber cartridge and short barrel life. Forcing that much incandescent gas through a small bore cannot be good for the barrel.
As it happened, shooters in North America and all over the world for once rewarded moderation and good design by laying down their hard earned cash for .243 and 6mm rifles, while sales of Holland's super magnum lagged. Today the .244 H&H Magnum is, as far as I can determine, obsolete. Given sufficient monetary incentive, however, Holland & Holland might be willing to make one up. No factory loaded ammunition or production rifles are offered in the caliber.
Nevertheless, the .244 H&H Magnum represents some sort of high water mark in the development of the 6mm cartridge. To use an aviation analogy, you could think of it as the Concorde of rifle cartridges.
.240 Apex (.240 Magnum Rimless)
The "Roaring 20's" saw the birth of another Holland & Holland creation, the .240 Apex (or .240 Magnum Rimless). This smaller belted magnum pretty much duplicated the performance of the much later .243 Winchester. No small feat given the limitations of the smokeless powders used by the British in 1920.
The .240 Apex was a belted rimless cartridge intended for use in repeating rifles. There was also a rimmed version, the .240 Magnum Flanged, designed for use in double rifles.
These are smaller cartridges than the .244 H&H Magnum, but still contain a worthwhile quantity of powder. The case of the .240 is about the same length as the 6mm-06, but a little smaller in diameter. Loaded to the same pressure with modern powder the .240 Apex has the potential to exceed the performance of the .243 WSSM.
The .240 case is of typical belted rimless configuration with a sharp shoulder and moderate body taper. Only its long neck (a plus!) reveals its age. The rim diameter is .467", the base diameter ahead of the belt .450", and the shoulder diameter .403". This case is 2.49" long and the COL is 3.21" long. Bullet diameter is given as .245 in Cartridges of the World, but I am pretty sure that reloaders could use standard .243" bullets without a problem.
The original factory ballistics call for a 100 grain bullet at a MV of 2900 fps and ME of 1870 ft. lbs. At 200 yards the factory figures are 2445 fps and 1330 ft. lbs. This was achieved by 40 grains of an unspecified and undoubtedly obsolete smokeless powder.
If a 100 grain Speer Grand Slam bullet with a BC of .351 were substituted for the original British Copper Point bullet the trajectory would look like this: +2.6" at 100 yards, +3" at 135 yards, +1.8" at 200 yards, -3" at 278 yards, and -5.2" at 300 yards. Thus the maximum point blank range of that load (+/- 3") is 278 yards.
According to the "Expanded Optimal Game Weight Table" that load should be effective on small 100 pound CXP2 class game at a maximum optimum distance of slightly over 400 yards. For large CXP2 class game weighing 200 pounds the maximum optimum range is 210 yards. It may be old, but there are no flies on the .240 Apex as a deer and antelope cartridge!
Why the .240 Apex did not achieve the world wide popularity enjoyed today by the .243 Winchester is anybody's guess. The .240 Apex cartridges I have seen were loaded with relatively blunt semi-spitzer bullets, which would not have helped the cartridge's downrange performance. Probably it was just too far ahead of its time, much like the .350 and 6.5mm Remington Short Magnums when they were introduced in the 1960's.
Copyright 2004, 2012 by Chuck Hawks. All rights reserved.