Load Specifications
Load data in caliber .401 Win. SL with .409 | 400gr | A-Square MONO RN bullet and 8 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Lovex S053, SNPE Vectan BA6 1/2 and ReloadSwiss RS 14.
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: 20"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| ADI AR 2205 | <<locked>> | 82% | 31,676 psi | 89% | 1178 fps | 98.1% |
| ADI AR 2207ᴾ | <<locked>> | 100% | 30,589 psi | 86% | 1276 fps | 95.8% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 25,976 psi | 73% | 784 fps | 100% |
| Lovex S053 | <<locked>> | 92% | 31,009 psi | 87% | 1230 fps | 98.1% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 24,961 psi | 70% | 801 fps | 100% |
| SNPE Vectan BA6 1/2 | <<locked>> | 94% | 30,937 psi | 87% | 1178 fps | 100% |
| Vihtavuori N110 | <<locked>> | 86% | 31,067 psi | 87% | 1211 fps | 100% |
| Vihtavuori N120ᴾ | <<locked>> | 100% | 31,270 psi | 88% | 1263 fps | 97.2% |
Recommended = one of the top powders for this cartridge and bullet combination.
Start Load - Barrel Length: 20"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| ADI AR 2205 | <<locked>> | 80% | 29,791 psi | 84% | 1155 fps | 97.6% |
| ADI AR 2207 | <<locked>> | 98% | 28,834 psi | 81% | 1250 fps | 95.1% |
| Hodgdon TrailBoss | <<locked>> | 80% | 18,695 psi | 53% | 696 fps | 100% |
| Lovex S053 | 14.8 gr | 82% | 23,496 psi | 66% | 1125 fps | 95.3% |
| ReloadSwiss RS 14 | 5.5 gr | 80% | 18,072 psi | 51% | 712 fps | 100% |
| SNPE Vectan BA6 1/2 | 13.2 gr | 80% | 21,509 psi | 61% | 1056 fps | 99.8% |
| Vihtavuori N110 | <<locked>> | 80% | 26,252 psi | 74% | 1152 fps | 99.9% |
| Vihtavuori N120 | <<locked>> | 94% | 26,629 psi | 75% | 1198 fps | 95.4% |
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 14 powders for .401 Win. SL loaded with the .409 | 400gr | A-Square MONO RN. ADI AR 2207 delivers the highest muzzle velocity at 1,276 fps; across all powders the maximum-charge window runs from 784 fps to 1,276 fps. ADI AR 2207 gives the best case fill at 100 %, and 14 of the 14 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (245 MPa), the top charges use 70–90 %, leaving at least 10 % headroom. The 400.0 gr projectile in 0.409" calls for a 1:19.0 twist; slower twists will usually not stabilise this weight. ADI AR 2207, 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. Lovex S053, SNPE Vectan BA6 1/2, ReloadSwiss RS 14 rank at the top here: for .401 Win. SL with the .409 | 400gr | A-Square MONO RN they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, Alliant Reloder-7, IMR 4227, Lovex D060 burn incompletely and react more sensitively to barrel length and temperature. Hodgdon TrailBoss, IMR 4227, Lovex S053 stay subsonic at start load. Always begin at the start load and work up in small increments while checking case and primer for pressure signs.