Load data for .300 Win. Mag. + 165gr Hornady ECX
The most recommended powders for this combination are ReloadSwiss RS 70, Alliant Reloder-17 and Vihtavuori N560.
Based on C.I.P., the max. allowed case length is 2.620 in / 66.55 mm, the max. cartridge length is 3.340 in / 84.84 mm, and the max. allowed pressure is 62,366 PSI / 4,300 bar.

Based on C.I.P., the max. allowed case length is 2.620 in / 66.55 mm, the max. cartridge length is 3.340 in / 84.84 mm, and the max. allowed pressure is 62,366 PSI / 4,300 bar.

Load Specifications
ImperialMetric
Bullet:.308 | 165gr | ECX
Cartridge:.300 Win. Mag. load data
Case Length (L3):2.620" | 66.5 mm
Cartridge Length (COL/L6):•••
Seated Depth:0.627" | 15.9 mm
Case Capacity:90.5 gow | 5.86 cm³
Primer Size:Large Rifle Magnum (LRM)
Max. Pressure (C.I.P.):62,366 psi | 4,300 bar
Barrel Length:24.0" | 610 mm
Min. Twist Rate:1:12.0
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Community Loads for .300 Win. Mag. + 165gr Hornady ECX
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) |
|---|---|---|---|---|---|
| 76.5 gr | 3.319" | 24.0" | 3123 fps | ••• | |
| 64.0 gr | 3.339" | 24.4" | 2753 fps | ••• | |
| 60.0 gr | 3.339" | 24.4" | 2520 fps | ••• | |
| ••• | 3.339" | 24.4" | 2641 fps | ••• | |
| ••• | 3.339" | 24.4" | 2684 fps | ••• | |
Charge weights beyond the first rows and all pressure values are only visible with an active Pro licence.