Load Specifications
Load data in caliber .303 Savage with .308 | 150gr | Woodleigh FN SN bullet and 13 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Alliant AR-Comp, Vihtavuori N130 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: 22"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2015 | <<locked>> | 92% | 35,215 psi | 90% | 2251 fps | 97.1% |
| Accurate 2495ᴾ | <<locked>> | 100% | 33,098 psi | 85% | 2290 fps | 97% |
| Alliant AR-Comp | <<locked>> | 94% | 34,708 psi | 89% | 2313 fps | 99.1% |
| Alliant Reloder-10x | <<locked>> | 86% | 34,055 psi | 87% | 2241 fps | 97.9% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 31,546 psi | 81% | 1473 fps | 100% |
| IMR 3031 | <<locked>> | 96% | 35,041 psi | 89% | 2323 fps | 95.8% |
| IMR 4198 | <<locked>> | 84% | 34,389 psi | 88% | 2195 fps | 98.7% |
| Norma 200 | <<locked>> | 82% | 34,084 psi | 87% | 2224 fps | 98.5% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 31,227 psi | 80% | 1506 fps | 100% |
| SNPE Vectan SP 3 | <<locked>> | 86% | 34,737 psi | 89% | 2234 fps | 96% |
| Vihtavuori N130 | <<locked>> | 88% | 35,099 psi | 90% | 2208 fps | 97.9% |
| Vihtavuori N133 | <<locked>> | 92% | 34,040 psi | 87% | 2192 fps | 96.4% |
| Vihtavuori N135 | <<locked>> | 98% | 33,620 psi | 86% | 2267 fps | 96.7% |
Recommended = one of the top powders for this cartridge and bullet combination.
Start Load - Barrel Length: 22"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2015 | <<locked>> | 88% | 31,067 psi | 79% | 2165 fps | 95.7% |
| Accurate 2495 | <<locked>> | 96% | 28,993 psi | 74% | 2198 fps | 95.5% |
| Alliant AR-Comp | 27.4 gr | 84% | 25,512 psi | 65% | 2080 fps | 95.7% |
| Alliant Reloder-10x | <<locked>> | 80% | 28,340 psi | 72% | 2110 fps | 96% |
| Hodgdon TrailBoss | <<locked>> | 80% | 23,119 psi | 59% | 1312 fps | 100% |
| IMR 3031 | <<locked>> | 94% | 32,851 psi | 84% | 2274 fps | 95% |
| IMR 4198 | <<locked>> | 80% | 30,661 psi | 78% | 2113 fps | 97.6% |
| Norma 200 | <<locked>> | 80% | 31,865 psi | 81% | 2178 fps | 98% |
| ReloadSwiss RS 14 | 9.3 gr | 80% | 23,018 psi | 59% | 1345 fps | 100% |
| SNPE Vectan SP 3 | <<locked>> | 84% | 32,851 psi | 84% | 2192 fps | 95.3% |
| Vihtavuori N130 | 25.5 gr | 80% | 27,412 psi | 70% | 2034 fps | 95.2% |
| Vihtavuori N133 | <<locked>> | 88% | 30,458 psi | 78% | 2113 fps | 95.1% |
| Vihtavuori N135 | <<locked>> | 94% | 29,762 psi | 76% | 2178 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 13 powders for .303 Savage loaded with the .308 | 150gr | Woodleigh FN SN. IMR 3031 delivers the highest muzzle velocity at 2,323 fps; across all powders the maximum-charge window runs from 1,473 fps to 2,323 fps. Accurate 2495 gives the best case fill at 100 %, and 13 of the 13 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (270 MPa), the top charges use 80–90 %, leaving at least 10 % headroom. Accurate 2495, 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. Alliant AR-Comp, Vihtavuori N130, ReloadSwiss RS 14 rank at the top here: for .303 Savage with the .308 | 150gr | Woodleigh FN SN they combine a high case fill with complete burn and sit in the upper velocity band. Always begin at the start load and work up in small increments while checking case and primer for pressure signs.