Load Specifications
Load data in caliber .350 Mag. Rigby with .356 | 145gr | LOS RN bullet and 23 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are IMR 3031, Norma 202 and Vihtavuori N140.
Important Notice: DO NOT go below Minimum Charge or above Maximum Charge. Since we have no control over the equipment and components used, any responsibility and liability for the results achieved is rejected.
Only powders/loads that match the current filter criteria are displayed: max pressure of a load ≤ 90% of max. standardized pressure, fill rate ≥ 80% and propellant combustion ≥ 95%. Use the sliders above the tables to adjust these thresholds.
Charge: Powder weight in grains. Start with the minimum load and work up carefully.
FR (Fill Rate): Case fill as a percentage. Values above 100% mean compressed loads.
MaxP / %: Maximum chamber pressure in bar and as a percentage of the standardized maximum for this caliber.
V(0): Muzzle velocity in feet per second (fps) at the standardized barrel length.
z (Powder Burn): Estimated propellant combustion percentage at bullet exit.
A valid access license is required to use the Personalized Load Calculator.
You can find more information in our FAQ: How can I use the Personalized Load Calculator?
Max Load - Barrel Length: 24"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2015 | <<locked>> | 84% | 38,406 psi | 85% | 3005 fps | 98.7% |
| Accurate 2460 | <<locked>> | 82% | 39,146 psi | 87% | 3038 fps | 96.3% |
| Accurate 2495 | <<locked>> | 92% | 39,537 psi | 88% | 3087 fps | 99.2% |
| Accurate 2520 | <<locked>> | 86% | 39,581 psi | 88% | 3084 fps | 96% |
| Accurate 4064 | <<locked>> | 94% | 39,552 psi | 88% | 3107 fps | 97.2% |
| Alliant AR-Comp | <<locked>> | 88% | 40,466 psi | 90% | 3150 fps | 100% |
| Hodgdon H322 | <<locked>> | 82% | 39,885 psi | 89% | 3087 fps | 97.7% |
| Hodgdon H335 | <<locked>> | 82% | 40,654 psi | 90% | 3097 fps | 97% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 33,170 psi | 74% | 2083 fps | 100% |
| IMR 3031 | <<locked>> | 88% | 38,493 psi | 86% | 3117 fps | 98.2% |
| Lovex D073.6 | <<locked>> | 90% | 40,582 psi | 90% | 3117 fps | 96.2% |
| Norma 202 | <<locked>> | 88% | 39,146 psi | 87% | 3064 fps | 96.6% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 33,344 psi | 74% | 2133 fps | 100% |
| Rottweil R 901 | <<locked>> | 86% | 40,596 psi | 90% | 3061 fps | 96.7% |
| Shooters World Match Rifle | <<locked>> | 90% | 40,582 psi | 90% | 3117 fps | 96.2% |
| SNPE Vectan Tubal 3000 | <<locked>> | 86% | 39,073 psi | 87% | 2972 fps | 96.5% |
| SNPE Vectan Tubal 5000 | <<locked>> | 92% | 38,247 psi | 85% | 2963 fps | 97.4% |
| Somchem S335 | <<locked>> | 86% | 38,348 psi | 85% | 2969 fps | 97.2% |
| Vihtavuori N130 | <<locked>> | 82% | 39,117 psi | 87% | 2982 fps | 99.4% |
| Vihtavuori N133 | <<locked>> | 86% | 38,812 psi | 86% | 2986 fps | 98.8% |
| Vihtavuori N135 | <<locked>> | 92% | 40,292 psi | 90% | 3100 fps | 99.3% |
| Vihtavuori N140 | <<locked>> | 90% | 39,494 psi | 88% | 3045 fps | 97.1% |
| Vihtavuori N540 | <<locked>> | 90% | 38,174 psi | 85% | 3022 fps | 96.1% |
Recommended = one of the top powders for this cartridge and bullet combination.
Start Load - Barrel Length: 24"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2015 | <<locked>> | 80% | 33,736 psi | 75% | 2887 fps | 97.6% |
| Accurate 2460 | <<locked>> | 80% | 36,535 psi | 81% | 2972 fps | 95.4% |
| Accurate 2495 | <<locked>> | 82% | 28,137 psi | 63% | 2782 fps | 95.8% |
| Accurate 2520 | <<locked>> | 84% | 36,927 psi | 82% | 3018 fps | 95% |
| Accurate 4064 | <<locked>> | 90% | 34,664 psi | 77% | 2982 fps | 95.6% |
| Alliant AR-Comp | <<locked>> | 80% | 30,937 psi | 69% | 2904 fps | 99% |
| Hodgdon H322 | <<locked>> | 80% | 37,318 psi | 83% | 3025 fps | 97% |
| Hodgdon H335 | <<locked>> | 80% | 37,971 psi | 84% | 3031 fps | 96.1% |
| Hodgdon TrailBoss | <<locked>> | 80% | 24,540 psi | 55% | 1867 fps | 100% |
| IMR 3031 | 64 gr | 82% | 31,575 psi | 70% | 2923 fps | 95.8% |
| Lovex D073.6 | <<locked>> | 88% | 37,927 psi | 84% | 3054 fps | 95.4% |
| Norma 202 | 68.3 gr | 86% | 36,651 psi | 82% | 2999 fps | 95.8% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 24,526 psi | 55% | 1909 fps | 100% |
| Rottweil R 901 | <<locked>> | 82% | 35,882 psi | 80% | 2943 fps | 95.1% |
| Shooters World Match Rifle | <<locked>> | 88% | 37,927 psi | 84% | 3054 fps | 95.4% |
| SNPE Vectan Tubal 3000 | <<locked>> | 84% | 36,753 psi | 82% | 2913 fps | 95.7% |
| SNPE Vectan Tubal 5000 | <<locked>> | 86% | 31,618 psi | 70% | 2792 fps | 95.1% |
| Somchem S335 | <<locked>> | 82% | 33,808 psi | 75% | 2854 fps | 95.7% |
| Vihtavuori N130 | <<locked>> | 80% | 36,811 psi | 82% | 2927 fps | 99% |
| Vihtavuori N133 | <<locked>> | 80% | 32,140 psi | 71% | 2815 fps | 97% |
| Vihtavuori N135 | <<locked>> | 80% | 27,122 psi | 60% | 2743 fps | 95.1% |
| Vihtavuori N140 | 68.7 gr | 86% | 34,664 psi | 77% | 2923 fps | 95.5% |
| Vihtavuori N540 | <<locked>> | 88% | 35,708 psi | 79% | 2959 fps | 95.2% |
Recommended = one of the top powders for this cartridge and bullet combination.
ᴾ possible press load - work up slowly to this load while watching for signs of excessive pressure.
This overview compares 58 powders for .350 Mag. Rigby loaded with the .356 | 145gr | LOS RN. ReloadSwiss RS 60 delivers the highest muzzle velocity at 3,166 fps; across all powders the maximum-charge window runs from 2,083 fps to 3,166 fps. Hodgdon TrailBoss gives the best case fill at 100 %, and 58 of the 58 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (310 MPa), the top charges use 74–90 %, leaving at least 10 % headroom. Hodgdon TrailBoss, ReloadSwiss RS 14 reach 100 % fill or more at maximum charge, so these are compressed loads: they need a long drop tube to seat cleanly and react sensitively to the case capacity of your own brass lot. IMR 3031, Norma 202, Vihtavuori N140 rank at the top here: for .350 Mag. Rigby with the .356 | 145gr | LOS RN they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, ADI AR 2206H, ADI Benchmark 8208, Alliant Power Pro 1200-R burn incompletely and react more sensitively to barrel length and temperature. Always begin at the start load and work up in small increments while checking case and primer for pressure signs.