.240 Apex

The .240 Magnum Rimless Holland & Holland (also known as the .240 Apex and the .240 Super Express) is a centrefire sporting rifle cartridge developed in English gunmakers Holland & Holland no later than 1919, primarily for use in hunting deer and plains game.

.240 Magnum Rimless
Type	Rifle
Place of origin	England
Production history
Designer	Holland & Holland
Designed	1919
Manufacturer	Holland & Holland
Specifications
Case type	Belted, bottleneck
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	Kynoch # 81
Ballistic performance
Bullet mass/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.

.240 Magnum Flanged
Specifications
Case type	Rimmed, bottleneck
Bullet diameter	.245 in (6.2 mm)
Neck diameter	.274 in (7.0 mm)
Shoulder diameter	.402 in (10.2 mm)
Base diameter	.448 in (11.4 mm)
Rim diameter	.513 in (13.0 mm)
Rim thickness	UNK
Case length	2.5 in (64 mm)
Overall length	3.25 in (83 mm)
Primer type	Kynoch # 81
Ballistic performance
Bullet mass/type Velocity Energy 100 gr (6 g) SN 2,775 ft/s (846 m/s) 1,711 ft⋅lbf (2,320 J)
Test barrel length: 28 Source(s): Kynoch

As it was common for rimless hunting cartridges, a rimmed (beltless) variant, at the time called just "Holland's 240 Super Express" and now sometimes named .240 Flanged Magnum or .240 H&H Flanged, was developed simultaneously for break-barrel rifles and combination guns.

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 with a diameter of .245 inches (contrary to the .240 name) 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.

Most bolt-action rifles made for the .240 H&H will be amply strong enough to handle hand-loaded 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)
.242 Rimless Nitro Express	100 gr (6.5 g)	2,800 ft/s (850 m/s)	1,740 ft⋅lbf (2,360 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)
.246 Purdey	100 gr (6.5 g)	2,950 ft/s (900 m/s)	1,930 ft⋅lbf (2,620 J)
6 mm Lee Navy	100 gr (6.5 g)	2,680 ft/s (820 m/s)	1,595 ft⋅lbf (2,163 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