Load data for .257 Weath. Mag. + 120gr Speer Boat-Tail
Based on C.I.P., the max. allowed case length is 2.549 in / 64.74 mm, the max. cartridge length is 3.209 in / 81.51 mm, and the max. allowed pressure is 63,817 PSI / 4,400 bar.
Based on C.I.P., the max. allowed case length is 2.549 in / 64.74 mm, the max. cartridge length is 3.209 in / 81.51 mm, and the max. allowed pressure is 63,817 PSI / 4,400 bar.
Load Specifications
ImperialMetric
Bullet:.257 | 120gr | Boat-Tail
Cartridge:.257 Weath. Mag. load data
Case Length (L3):2.549" | 64.7 mm
Cartridge Length (COL/L6):•••
Seated Depth:0.519" | 13.2 mm
Case Capacity:84 gow | 5.44 cm³
Primer Size:Large Rifle Magnum (LRM)
Max. Pressure (C.I.P.):63,817 psi | 4,400 bar
Barrel Length:26.0" | 660 mm
Min. Twist Rate:1:10.5
Get PRO license to unlock all data and calculators
Community Loads for .257 Weath. Mag. + 120gr Speer Boat-Tail
Real loads for this combination shared by our community. Charge weights are only fully visible with an active Pro licence.
| Powder | Charge (gr) | C.O.L. | Barrel Length | Velocity (fps) | Pressure (psi) |
|---|---|---|---|---|---|
| 62.0 gr | 3.170" | — | 2976 fps | ••• | |
| 64.0 gr | 3.170" | — | 3068 fps | ••• | |
| 59.0 gr | 3.170" | — | 2929 fps | ••• | |
| ••• | 3.170" | 24.0" | 3034 fps | ••• | |
| ••• | 3.170" | — | 3017 fps | ••• | |
| ••• | 3.170" | — | 3148 fps | ••• | |
| ••• | 3.170" | — | 3010 fps | ••• | |
| ••• | 3.170" | 24.0" | 3109 fps | ••• | |
| ••• | 3.170" | — | 3180 fps | ••• | |
| ••• | 3.170" | — | 2881 fps | ••• | |
| ••• | 3.170" | — | 3245 fps | ••• | |
| ••• | 3.170" | — | 2972 fps | ••• | |
| ••• | 3.170" | — | 3062 fps | ••• | |
| ••• | 3.170" | — | 2996 fps | ••• | |
| ••• | 3.170" | — | 3083 fps | ••• | |
| ••• | 3.170" | — | 3134 fps | ••• | |
| ••• | 3.170" | — | 3317 fps | ••• | |
| ••• | 3.170" | — | 2845 fps | ••• | |
| ••• | 3.170" | — | 3138 fps | ••• | |
| ••• | 3.170" | — | 2973 fps | ••• | |
| ••• | 3.170" | — | 3149 fps | ••• | |
| ••• | 3.170" | — | 2956 fps | ••• | |
| ••• | 3.170" | — | 3137 fps | ••• | |
| ••• | 3.170" | — | 3055 fps | ••• | |
| ••• | 3.170" | — | 3148 fps | ••• | |
Charge weights beyond the first rows and all pressure values are only visible with an active Pro licence.