.30-378 Weatherby Magnum
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| .30-378 Weatherby Magnum | ||
|---|---|---|
| Type | Rifle | |
| Place of origin | USA | |
| Production history | ||
| Designer | Weatherby | |
| Designed | 1996 | |
| Manufacturer | Weatherby | |
| Produced | 1996 - Current | |
| Specifications | ||
| Parent case | .378 Weatherby Magnum | |
| Bullet diameter | .308 in (7.8 mm) | |
| Neck diameter | .337 in (8.6 mm) | |
| Shoulder diameter | .561 in (14.2 mm) | |
| Base diameter | .582 in (14.8 mm) | |
| Rim diameter | .579 in (14.7 mm) | |
| Case length | 2.913 in (74.0 mm) | |
| Overall length | 3.690 in (93.7 mm) | |
| Rifling twist | 1-10" | |
| Primer type | Large rifle magnum | |
| Maximum pressure | 63,817 psi (440.00 MPa) | |
| Ballistic performance | ||
| Bullet weight/type | Velocity | Energy |
| 165 gr (10.7 g) BST | 3,500 ft/s (1,100 m/s) | 4,488 ft·lbf (6,085 J) |
| 180 gr (12 g) BST | 3,420 ft/s (1,040 m/s) | 4,676 ft·lbf (6,340 J) |
| 200 gr (13 g) Partition | 3,160 ft/s (960 m/s) | 4,434 ft·lbf (6,012 J) |
| Test barrel length: 26" (660 mm) Source: Weatherby [1] |
||
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 (.308 inches/7.8 millimetres) 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 3,500 ft/s (1,100 m/s) and muzzle energies over 4,750 foot-pounds force (6,440 J).[1] The cartridge was originally designed for hunting game at very long distances, and for marksmanship competition in excess of 1,000 yards (910 m).
Contents |
[edit] Performance
The .30-378 case holds as much as 120 grains (8 g) 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 200 grains (13 g) are loaded, the .30-378 can exceed the .458 Winchester Magnum in terms of both Muzzle Energy and Taylor Knockout Value.
| Cartridge | Bullet Weight | Muzzle velocity | Muzzle energy | Notes | |||
|---|---|---|---|---|---|---|---|
| gr | g | ft/s | m/s | ft·lbf | J | ||
| .458 Win Mag | 350 | 23 | 2,589 | 789 | 5,211 | 7,065 | Not comparable to the .30-378 Wby. |
| .338 Lapua | 300 | 19 | 2,677 | 816 | 4,775 | 6,474 | Higher BC for better downrange performance |
| .30-378 Wby | 165 | 10.7 | 3,500 | 1,100 | 4,757 | 6,450 | |
| .375 H&H | 300 | 19 | 2,645 | 806 | 4,661 | 6,319 | |
| .300 RUM | 180 | 12 | 3,300 | 1,000 | 4,354 | 5,903 | similar to the .300 Win Mag, but outperforms it with heavy bullets. |
| .300 Win Mag | 180 | 12 | 3,050 | 930 | 3,720 | 5,040 | Reference load by Doubletapammo |
Note: Using the bullet weight and muzzle velocity in each cartridge that provided the maximum muzzle energy. Data for the .30-378 is from [1]. Loading data for all other cartridges can be found at [2]
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).
| Cartridge | Weight | Ballistic Coefficient |
Muzzle Velocity | Muzzle Energy | Velocity at 440 yd | Energy at 440 yd | |||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| gr | g | ft/s | m/s | ft·lbf | J | ft/s | m/s | ft·lbf | J | ||
| .30-06 | 165 | 11 | 0.475 | 2,938 | 896 | 3,165 | 4,291 | 2,110 | 640 | 1,633 | 2,214 |
| .30-378 | 165 | 11 | 0.475 | 3,500 | 1,100 | 4,448 | 6,031 | 2,576 | 785 | 2,428 | 3,292 |
| .30-06 | 180 | 12 | 0.507 | 2,798 | 853 | 3,130 | 4,240 | 2,044 | 623 | 1,668 | 2,262 |
| .30-378 | 180 | 12 | 0.507 | 3,420 | 1,040 | 4,676 | 6,340 | 2,559 | 780 | 2,619 | 3,551 |
| .30-06 | 200 | 13 | 0.481 | 2,586 | 788 | 2,972 | 4,029 | 1,841 | 561 | 1,502 | 2,036 |
| .30-378 | 200 | 13 | 0.481 | 3,160 | 960 | 4,434 | 6,012 | 2,300 | 700 | 2,351 | 3,188 |
Note: data for the .30-378 from Weatherby[1] (which tracks closely to what handloaders can achieve based on loading data at [2]. Data from the .30-06 is also from Hodgdon.[2] The initial data used is included here for anyone who cares to run the calculations themselves.
[edit] 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.[3] 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.
[edit] See also
[edit] References
- ^ a b c d Ammo info at Weatherby
- ^ a b c Hodgdon online reloading data
- ^ Weatherby Ammunition prices at Midway for confirmation of atypical cartridge costs.
- Who Wins? The .30-378 Versus The 7 mm STW at Gun-Tests.com
- .30-378 Weatherby by Chuck Hawks
- The .300 Super Magnums by Chuck Hawks
- Cartridge Dimensions at Steve's Pages
[edit] External links
- Further reloading data at Hodgdon
