.30-378 Weatherby Magnum

Infobox Firearm Cartridge
name= .30-378 Weatherby Magnum


caption=
origin= USA
type= Rifle
designer= Weatherby
design_date=1959 by request of US Army for long range rifle.
manufacturer=Weatherby
production_date=1996 - Current
number=
variants=
is_SI_specs=
parent=.378 Weatherby Magnum
case type=belted magnum
bullet=.308
neck=.337
shoulder=.561
base=.582
rim_dia=.579
rim_thick=
case_length=2.913
length=3.690
rifling=1-10"
primer=Large rifle magnum
max_pressure=63817
max_cup=
is_SI_ballistics=
bw1=165
btype1=BST
vel1=3500
en1=4488
bw2=180
btype2=BST
vel2=3420
en2=4676
bw3=200
btype3=Partition
vel3=3160
en3=4434
bw4=
btype4=
vel4=
en4=
test_barrel_length=26" (660 mm)
balsrc= Weatherby [http://www.weatherby.com/products/ammo.asp?prd_id=8 Ammo info at Weatherby] ] The .30-378 Weatherby Magnum is a cartridge introduced by Weatherby in 1996 that uses the same case as the previously existing .378 Weatherby Magnum and .460 Weatherby Magnum, necked down to a 30 caliber (convert|.308|in|disp=s) bullet. It is offered with bullets between 165 and 200 grains (10.7 g and 13.0 g) in factory loading, generating velocities able to exceed convert|3500|ft/s|lk=on|abbr=on and muzzle energies over convert|4750|ftlbf|J. The cartridge was originally designed for hunting game at very long distances, and for marksmanship competition in excess of convert|1000|yd|m.

Performance

The .30-378 case holds as much as convert|120|gr|0 of powder without requiring a compressed load. This allows the cartridge to develop more energy than the .300 Remington Ultra Magnum, .300 Winchester Magnum and .375 H&H Magnum, especially when handloads are used. The .30-378 has comparable muzzle energy to the larger .338 Lapua in military use. When bullets heavier than convert|200|gr are loaded, the .30-378 can exceed the .458 Winchester Magnum in terms of both Muzzle Energy and Taylor Knockout Value. However bullets of this weight are not generally offered in factory loadings, requiring one to be a hand-loader in order to take advantage of the additional power potential.

Note: Using the bullet weight and muzzle velocity in each cartridge that provided the maximum muzzle energy. Data for the .30-378 is from . Loading data for all other cartridges can be found at [http://data.hodgdon.com/cartridge_load.asp Hodgdon online reloading data] ]

Weatherby claims the .30-378 is currently the most powerful .30 caliber cartridge in the world, retaining more energy and velocity at one quarter mile than is possessed by a .30-06 upon leaving the barrel. However, the later claim appears not to be accurate when you compare bullets of the same weight, based on a check of available data (See chart below).

Note: data for the .30-378 from Weatherby (which tracks closely to what handloaders can achieve based on loading data at . Data from the .30-06 is also from Hodgdon. The initial data used is included here for anyone who cares to run the calculations themselves.

Costs

Rifles built by Weatherby are available in .30-378, and ammunition is significantly more expensive than other cartridges, with ammunition costing upwards of $100 USD for a box of 20 rounds as of 2007. [ [http://www.midwayusa.com/ebrowse.exe/browse?TabID=3&Categoryid=7646&categorystring=653***690*** Weatherby Ammunition prices at Midway] for confirmation of atypical cartridge costs.] Weatherby offers this caliber in several versions of its Mark V rifle. Due to the strong recoil a round of this energy can create, all Weatherby rifles offered in this caliber include a muzzle-brake.
Sako offers the TRG-S also in .30-378 Weatherby.

ee also

* List of rifle cartridges
* 7 mm caliber

References

* [http://www.gun-tests.com/performance/jul97versus.html Who Wins? The .30-378 Versus The 7 mm STW] at Gun-Tests.com
* [http://www.chuckhawks.com/30-378Wby.htm .30-378 Weatherby] by Chuck Hawks
* [http://www.chuckhawks.com/300super_mags.htm The .300 Super Magnums] by Chuck Hawks
* [http://www.stevespages.com/jpg/cd30378weatherby.jpgCartridge Dimensions] at Steve's Pages

External links

* Further reloading data at [http://data.hodgdon.com/cartridge_load.asp Hodgdon]