In recent years there has been a trend among wildcat cartridge aficionados toward outsized "super" .300 magnums. In 1996 Weatherby responded to this trend by chambering their Mark V rifle for the huge .30-378 Belted Magnum.

Weatherby factory ballistics for the .30-378 call for a 165 grain bullet (SD .248) at a MV of 3500 fps with ME of 4488 ft. lbs., a 180 grain bullet (SD .271) at a MV of 3,420 fps with ME of 4676 ft. lbs., and a 200 grain bullet (SD .301) at a MV of 3,160 fps with ME of 4434 ft. lbs. Weatherby ballistics tables show the following trajectory for the 180 grain Nosler Ballistic Tip bullet: +2.5" at 100 yards, +3.1" at 200 yards, 0 at 300 yards, and -7.5" at 400 yards.

Hodgdon Powder Company reloading data shows that a 180 grain Speer boat-tail spitzer bullet can be driven at a velocity of 3213 fps by 105.0 grains of H870 powder, and to a MV of 3412 fps by 111.0 grains of H1000. The 200 grain Barnes X-Bullet tested by Hodgdon could be driven to a MV of 3105 fps by 113.0 grains of H870 powder, and to 3206 fps by 116.0 grains of H870.

Last but certainly not least, the 220 grain Nosler Partition bullet could be driven to a MV of 3098 fps by 113.0 grains of H870 powder, and a MV of 3180 fps by 116.0 grains of H870. With a well placed bullet this should do for any animal on earth, although no .30 caliber cartridge it really the best choice for heavy, dangerous game. These velocities were all achieved in a 26" barrel and used Weatherby brass and Federal 215M primers.

Note: A complete article about the .30-378 Wby. Mag. can be found on the Rifle Cartridge Page.