CaliberAtlas › .338-378 Wby. Mag.
Common uses: Hunting, Big Game, Long Range
| Type | rifle (centerfire) |
| Typical load | 250gr SPBT |
| Muzzle velocity | 3000 fps |
| Muzzle energy | 4997 ft-lb |
| G1 ballistic coefficient | 0.473 |
| Case length | 73.8 mm |
| Overall length | 95.3 mm |
| SAAMI max pressure | 65000 PSI |
| Range (yd) | Velocity (fps) | Energy (ft-lb) | Drop (in) |
|---|---|---|---|
| 0 | 3000 | 4997 | 0 |
| 100 | 2850 | 4510 | -7 |
| 200 | 2708 | 4070 | -27 |
| 300 | 2572 | 3673 | -60 |
| 400 | 2444 | 3315 | -107 |
| 500 | 2321 | 2992 | -167 |
Guidelines only — ammunition choice, conditions, and shooter skill matter. Always follow local laws.
The .338-378 Wby. Mag. is a centerfire rifle cartridge, delivering very powerful energy on target, which shapes where it fits between varmint work, big-game hunting, and precision shooting. A representative 250-grain loading leaves the muzzle at roughly 3000 fps and carries about 4997 ft-lbs of energy, with a G1 ballistic coefficient near 0.473. Those numbers place it squarely in its intended performance envelope. Based on its energy and trajectory, ethical ranges work out to roughly medium game such as deer to about 500 yards; larger game to about 600 yards — always within the limits of your own accuracy and local regulations. Recoil is generally stout for the class, and our database tracks 1 factory loading so you can compare bullet weights and velocities for your specific use. Figures here are for reference and informational use — always verify against manufacturer data.
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