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. (Excessive pressure, probably heat induced, is the suspected culprit in the case of the .416 Rem.) Unlike the .416 Rigby, the new .400 H&H is based on the .375 H&H case and does not require an oversize action.

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 also intended to generate moderate recoil and muzzle blast without the necessity for barrel porting or muzzle brakes.

Specifications of interest to reloaders include a standard magnum rim diameter of .532". Overall case length is 2.85" (the same as the .375 case), and the cartridge overall length is 3.50". 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.

In addition, Hornady offers a 300 grain .411" Interlock bullet to reloaders. This bullet is intended for the .405 Winchester, and with moderate reloads it should be quite suitable for North American CXP3 game in the .400 H&H. And one could probably use .410" jacketed pistol bullets intended for the .41 Magnum revolver cartridge for low velocity, low recoil practice loads.

I have yet to see any reloading data for the .300 H&H, but I suspect that medium burning rate rifle powders such as H335, H4895, RL-12, and IMR 4895 might be a reasonable place to start.

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 100 yards the figures are 2157 fps and 4125 ft. lbs. These numbers are for a rifle with a 24" barrel.

Factory 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.

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 looks like a winner.

Note: A full length article about the .400 H&H Magnum can be found on the Rifle Cartridge Page.