Load data for .257 Roberts + 120gr Nosler Partition
The most recommended powders for this combination are IMR 4350.
Based on C.I.P., the max. allowed case length is 2.233 in / 56.72 mm, the max. cartridge length is 2.775 in / 70.49 mm, and the max. allowed pressure is 51,488 PSI / 3,550 bar.
Based on C.I.P., the max. allowed case length is 2.233 in / 56.72 mm, the max. cartridge length is 2.775 in / 70.49 mm, and the max. allowed pressure is 51,488 PSI / 3,550 bar.
Load Specifications
ImperialMetric
Bullet:.257 | 120gr | Partition
Cartridge:.257 Roberts load data
Case Length (L3):2.233" | 56.7 mm
Cartridge Length (COL/L6):•••
Seated Depth:0.658" | 16.7 mm
Case Capacity:58 gow | 3.76 cm³
Primer Size:Large Rifle (LR)
Max. Pressure (C.I.P.):51,488 psi | 3,550 bar
Barrel Length:24.0" | 610 mm
Min. Twist Rate:1:10.0
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Community Loads for .257 Roberts + 120gr Nosler Partition
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) |
|---|---|---|---|---|---|
| 38.0 gr | 2.750" | 24.0" | 2664 fps | ••• | |
| 38.0 gr | 2.750" | 24.0" | 2595 fps | ••• | |
| 40.0 gr | 2.750" | 24.0" | 2715 fps | ••• | |
| ••• | 2.750" | 24.0" | 2506 fps | ••• | |
| ••• | 2.750" | 24.0" | 2625 fps | ••• | |
| ••• | 2.750" | 24.0" | 2548 fps | ••• | |
| ••• | 2.750" | 24.0" | 2666 fps | ••• | |
| ••• | 2.750" | 24.0" | 2783 fps | ••• | |
| ••• | 2.750" | 24.0" | 2686 fps | ••• | |
| ••• | 2.750" | 24.0" | 2616 fps | ••• | |
| ••• | 2.750" | 24.0" | 2747 fps | ••• | |
| ••• | 2.750" | 24.0" | 2878 fps | ••• | |
Charge weights beyond the first rows and all pressure values are only visible with an active Pro licence.