.240 Apex

.240 Holland & Holland Magnum
Type	Rifle
Place of origin	England
Production history
Designer	Holland & Holland
Designed	1920
Manufacturer	Holland & Holland
Variants	.240 Flanged
Specifications
Case type	Rimless, Rimmed
Bullet diameter	.245 in (6.2 mm)
Neck diameter	.274 in (7.0 mm)
Shoulder diameter	.403 in (10.2 mm)
Base diameter	.450 in (11.4 mm)
Rim diameter	.467 in (11.9 mm)
Rim thickness	.035 in (0.89 mm)
Case length	2.49 in (63 mm)
Overall length	3.21 in (82 mm)
Primer type	Berdan
Ballistic performance
Bullet weight/type Velocity Energy 100 gr (6 g) SP 2,900 ft/s (880 m/s) 1,865 ft·lbf (2,529 J)
Source(s): "Cartridges of the World"

The .240 Holland & Holland Magnum (also known as the .240 Apex, .240 Belted Nitro Express, .240 Magnum Rimless, or .240 Super Express) is a centrefire sporting rifle cartridge developed in England in the 1920s, primarily for use in hunting deer and plains game. This round has always been closely associated with the firm of Holland & Holland, rifle and gun makers of London, England, which has built more magazine and double rifles in this calibre than anyone else. A rimmed variant of this cartridge, known as the .240 Magnum Flanged, was developed for use in double rifles.

Overview

The ballistic performance of the .240 H&H in factory loads is very similar to that of the .243 Winchester, with a 100-grain (6.5 g) bullet giving a muzzle velocity of approximately 2,900 feet per second (880 m/s). When it is loaded at the same pressure as the .243 WSSM using modern powders, the .240 H&H has the potential for slightly better performance.

The case dimensions of the .240 are not unlike those of the wildcat 6mm-06 (the .30-06 Springfield cartridge case necked down to accept a 6mm/.244 bullet), but the .240 case has a fractionally, .002, larger diameter, and the case is distinctive in appearance owing to its long neck. bullets for the .243 Winchester will need to be plated out to .245 to ensure that they are bore-riding.

Most bolt-action rifles made for the .240 H&H will be amply strong enough to handle handloaded cartridges at high pressure.

.240 H&H Performance Comparison

Cartridge	Bullet weight	Muzzle velocity	Muzzle energy
.240 H&H Magnum	100 gr (6.5 g)	2,900 ft/s (880 m/s)	1,865 ft·lbf (2,529 J)
.240 Weatherby Magnum	100 gr (6.5 g)	3,406 ft/s (1,038 m/s)	2,576 ft·lbf (3,493 J)
.243 Winchester	100 gr (6.5 g)	2,960 ft/s (900 m/s)	1,945 ft·lbf (2,637 J)
.243 Winchester Super Short Magnum	100 gr (6.5 g)	3,110 ft/s (950 m/s)	2,147 ft·lbf (2,911 J)
.244 H&H Magnum	100 gr (6.5 g)	3,500 ft/s (1,100 m/s)	2,720 ft·lbf (3,690 J)
6 mm Remington	100 gr (6.5 g)	3,100 ft/s (940 m/s)	2,133 ft·lbf (2,892 J)

See also

• List of rifle cartridges
• 6 mm caliber