| .240 Magnum Rimless | |
| Origin: | England |
| Type: | Rifle |
| Designer: | Holland & Holland |
| Design Date: | 1919 |
| Manufacturer: | Holland & Holland |
| Case Type: | Belted, bottleneck |
| Bullet: | .245 |
| Neck: | .274 |
| Shoulder: | .403 |
| Base: | .450 |
| Rim Dia: | .467 |
| Rim Thick: | .035 |
| Case Length: | 2.49 |
| Length: | 3.21 |
| Primer: | Kynoch # 81 |
| Bw1: | 100 |
| Btype1: | SP |
| Vel1: | 2900 |
| En1: | 1865 |
| Balsrc: | Cartridges of the World.[1] |
| .240 Magnum Flanged | |
| Case Type: | Rimmed, bottleneck |
| Bullet: | .245 |
| Neck: | .274 |
| Shoulder: | .402 |
| Base: | .448 |
| Rim Dia: | .513 |
| Rim Thick: | UNK |
| Case Length: | 2.5 |
| Length: | 3.25 |
| Primer: | Kynoch # 81 |
| Bw1: | 100 |
| Btype1: | SN |
| Vel1: | 2775 |
| En1: | 1711 |
| Test Barrel Length: | 28 |
| Balsrc: | Kynoch[2] |
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,[3] primarily for use in hunting deer and plains game.[1]
As it was common for rimless hunting cartridges, a rimmed (beltless) variant, at the time called just "Holland's 240 Super Express"[4] and now sometimes named .240 Flanged Magnum or .240 H&H Flanged, was developed simultaneously for break-barrel rifles and combination guns.[5]
The ballistic performance of the .240 H&H in factory loads is very similar to that of the .243 Winchester, with a 100gr bullet with a diameter of .245 inches (contrary to the .240 name) giving a muzzle velocity of approximately 2900ft/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 Magnum | 100gr | 2900ft/s | 1865ft·lbf | |
| 100gr | 3406ft/s | 2576ft·lbf | ||
| 100gr | 2800ft/s | 1740ft·lbf | ||
| 100gr | 2960ft/s | 1945ft·lbf | ||
| 100gr | 3110ft/s | 2147ft·lbf | ||
| 100gr | 3500ft/s | 2720ft·lbf | ||
| 100gr | 2950ft/s | 1930ft·lbf | ||
| 100gr | 2680ft/s | 1595ft·lbf | ||
| 100gr | 3100ft/s | 2133ft·lbf |