The .400 H&H Magnum Belted Rimless
By Chuck Hawks
The venerable British firm that patented the belted magnum case in 1904 and released the world famous .375 H&H Magnum in 1912 is at it again. The new .400 Holland & Holland Magnum cartridge is a big bore cartridge intended to work in a conventional (.375 H&H) full length magnum action while avoiding the problems of the .416 Remington Magnum. Unlike the .416 Rigby, the new .400 H&H does not require an oversize action.
The .416 Rem. Mag. has suffered from unreliability in the intense heat sometimes encountered during hunts in sub-Saharan Africa. Stuck cases and the odd pressure spike (with .416 Rem. factory loaded ammunition), while relatively infrequent, have become a cause for concern, as are broken extractors. These problems are reported often enough to disquiet African professional hunters and guides. As I have tried to point out in previous articles, ANY problem is magnified when facing an animal intent on biting or mashing you! Excessive pressure, probably heat induced, is the suspected culprit.
Holland & Holland seek to avoid these problems with their new .400. The .400 H&H will be loaded to moderate pressure and uses a slightly tapered case with sloping shoulders for maximum feed reliability in bolt action rifles. This is a cartridge designed for 100% reliability in African climates and its intended use is against large, dangerous animals. It is not intended to be trendy and H&H eschews the modern practice of basing hunting cartridge design on principles developed for unrelated shooting sports, such as competitive bench rest shooting. A century of successful experience in the field with such stalwart hunting cartridges as the .300 H&H and .375 H&H has proven the wisdom of Holland's cartridge design approach.
The new .400 is also intended to generate moderate recoil and muzzle blast (for a big bore) without the necessity for barrel porting or muzzle brakes. "Avoiding the most spiteful recoil" is how H&H put it.
Holland & Holland understand that bullet placement is the key to quick kills and that it is the combination of rifle, cartridge and shooter that achieves this. The legend "But always remember, no amount of powder will make up for poor bullet placement." is prominently displayed on their WebSite.
The new .400 H&H case is based on the .375 H&H case. It uses the same .532" diameter rim. The case head diameter immediately in front of the rim is .513" tapering to .492" just behind the beginning of the shoulder. The moderately angled shoulder is .182" long and the neck diameter is .441". Overall case length is 2.85" (the same as the .375 case) and the standard cartridge overall length is 3.50". H&H intend to release this design for general use; it will not be proprietary.
Bullet diameter is .411" and factory loaded bullets are to be supplied by Woodleigh of Australia. These will be the same 400 grain Premium solid and Weldcore soft point bullets sold to reloaders and used in .450/400 NE factory loads.
The performance goal is to increase the muzzle energy (ME) of the .375 H&H by about 25%. This means delivering approximately the same energy at 100 yards as the .375 does at the muzzle, or at 200 yards as the .375 does at 100 yards. Holland & Holland factory load ballistics call for a 400 grain bullet at a muzzle velocity of 2375 fps and ME of 5011 ft. lbs. At 50 yards the figures are 2253 fps and 4565 ft. lbs. At 100 yards the figures are 2157 fps and 4125 ft. lbs. At 150 yards the figures are 2049 fps and 3735 ft. lbs. At 200 yards the figures are 1947 fps and 3365 ft. lbs. These numbers are for a rifle with a 24" barrel.
Most dangerous game is killed at less than 100 yards, so the new .400 H&H uses round nose bullets at moderate velocity designed to give good performance out to at least 200 yards. Holland & Holland trajectory tables computed for a rifle with a telescopic sight mounted 1.5" over the bore show that if a .400 H&H rifle is zeroed at 175 yards, the bullet will deviate no more than 2" above or below the line of sight from the muzzle to 200 yards.
A maximum point blank range (+/- 2") of 200 yards is more than satisfactory for a dangerous game rifle. So sighted, the .375 (300 grain RN), .400 (400 grain RN), and .465 (480 grain RN) H&H Belted Magnum cartridges all have quite similar trajectories and allow identical aiming points out to 200 yards. The dedicated dangerous game hunter can use two or all three of these cartridges interchangeably without considering trajectory.
Since the .375 H&H has a ME of about 4100 ft. lbs. with a 300 grain solid bullet (British figures), it can be said that the new .400 H&H Magnum achieves its intended design goal. Holland & Holland reports that the pressure is modest and accuracy excellent (but provided no exact figures) with prototype cartridges. The proof will be what happens in the field, but the new .400 H&H seems to be an exceptionally well thought out design for a new dangerous game cartridge.
Copyright 2003, 2012 by Chuck Hawks. All rights reserved.