Load Specifications
Load data in caliber .350 Mag. Rigby with .356 | 125gr | SNS Coated Bullets RN bullet and 15 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are IMR 3031, Alliant AR-Comp and Accurate 2495.
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.
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Max Load - Barrel Length: 24"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2015 | <<locked>> | 88% | 38,725 psi | 86% | 3202 fps | 97.6% |
| Accurate 2495 | <<locked>> | 96% | 39,276 psi | 87% | 3278 fps | 98.1% |
| Alliant AR-Comp | <<locked>> | 92% | 40,654 psi | 90% | 3353 fps | 99.8% |
| Alliant Reloder-10x | <<locked>> | 84% | 39,160 psi | 87% | 3245 fps | 98.6% |
| Baschieri & Pellagri 106 | <<locked>> | 82% | 39,827 psi | 89% | 3150 fps | 96.8% |
| Hodgdon H322 | <<locked>> | 86% | 40,654 psi | 90% | 3297 fps | 96.4% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 32,329 psi | 72% | 2221 fps | 100% |
| IMR 3031 | <<locked>> | 92% | 38,682 psi | 86% | 3310 fps | 96.7% |
| IMR 4198 | <<locked>> | 84% | 40,640 psi | 90% | 3245 fps | 99.4% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 32,358 psi | 72% | 2274 fps | 100% |
| SNPE Vectan SP 3 | <<locked>> | 84% | 39,798 psi | 89% | 3251 fps | 97% |
| SNPE Vectan Tubal 5000 | <<locked>> | 96% | 38,624 psi | 86% | 3150 fps | 95.8% |
| Vihtavuori N130 | <<locked>> | 86% | 39,885 psi | 89% | 3192 fps | 98.6% |
| Vihtavuori N133 | <<locked>> | 90% | 39,450 psi | 88% | 3189 fps | 97.7% |
| Vihtavuori N135 | <<locked>> | 96% | 40,030 psi | 89% | 3291 fps | 98.1% |
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>> | 82% | 31,966 psi | 71% | 3018 fps | 95.2% |
| Accurate 2495 | 71.1 gr | 90% | 31,821 psi | 71% | 3077 fps | 95.7% |
| Alliant AR-Comp | 62.5 gr | 80% | 27,412 psi | 61% | 2956 fps | 95.8% |
| Alliant Reloder-10x | <<locked>> | 80% | 34,505 psi | 77% | 3120 fps | 97.4% |
| Baschieri & Pellagri 106 | <<locked>> | 80% | 37,318 psi | 83% | 3084 fps | 96% |
| Hodgdon H322 | <<locked>> | 84% | 38,029 psi | 85% | 3228 fps | 95.5% |
| Hodgdon TrailBoss | <<locked>> | 80% | 23,830 psi | 53% | 1995 fps | 100% |
| IMR 3031 | 70.3 gr | 90% | 36,332 psi | 81% | 3245 fps | 95.9% |
| IMR 4198 | <<locked>> | 80% | 36,027 psi | 80% | 3127 fps | 98.6% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 23,714 psi | 53% | 2041 fps | 100% |
| SNPE Vectan SP 3 | <<locked>> | 80% | 34,853 psi | 78% | 3117 fps | 95.4% |
| SNPE Vectan Tubal 5000 | <<locked>> | 94% | 36,332 psi | 81% | 3091 fps | 95% |
| Vihtavuori N130 | <<locked>> | 80% | 33,054 psi | 74% | 3012 fps | 96.7% |
| Vihtavuori N133 | <<locked>> | 84% | 32,619 psi | 73% | 3005 fps | 95.4% |
| Vihtavuori N135 | <<locked>> | 88% | 30,879 psi | 69% | 3038 fps | 95% |
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 43 powders for .350 Mag. Rigby loaded with the .356 | 125gr | SNS Coated Bullets RN. Alliant AR-Comp delivers the highest muzzle velocity at 3,353 fps; across all powders the maximum-charge window runs from 2,221 fps to 3,353 fps. Hodgdon TrailBoss gives the best case fill at 100 %, and 43 of the 43 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (310 MPa), the top charges use 72–90 %, leaving at least 10 % headroom. Hodgdon TrailBoss, ReloadSwiss RS 14, Vihtavuori N150 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, Alliant AR-Comp, Accurate 2495 rank at the top here: for .350 Mag. Rigby with the .356 | 125gr | SNS Coated Bullets RN they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, Accurate 2460, Accurate 2520, ADI Benchmark 8208 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.