Load Specifications
Load data in caliber .303 Savage with .308 | 150gr | Sellier & Bellot SP 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, ReloadSwiss RS 14 and Hodgdon TrailBoss.
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% | 35,056 psi | 90% | 2251 fps | 97.1% |
| Accurate 2495ᴾ | <<locked>> | 100% | 33,286 psi | 85% | 2293 fps | 97.1% |
| Alliant AR-Comp | <<locked>> | 94% | 34,548 psi | 88% | 2310 fps | 99.1% |
| Alliant Reloder-10x | <<locked>> | 86% | 33,924 psi | 87% | 2238 fps | 97.9% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 31,473 psi | 80% | 1473 fps | 100% |
| IMR 3031 | <<locked>> | 96% | 34,896 psi | 89% | 2320 fps | 95.8% |
| IMR 4198 | <<locked>> | 84% | 34,592 psi | 88% | 2201 fps | 98.7% |
| Norma 200 | <<locked>> | 82% | 33,968 psi | 87% | 2224 fps | 98.5% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 31,140 psi | 80% | 1506 fps | 100% |
| SNPE Vectan SP 3 | <<locked>> | 86% | 34,998 psi | 89% | 2241 fps | 96.1% |
| Vihtavuori N130 | <<locked>> | 88% | 34,954 psi | 89% | 2205 fps | 97.8% |
| Vihtavuori N133 | <<locked>> | 92% | 34,243 psi | 87% | 2198 fps | 96.5% |
| Vihtavuori N135 | <<locked>> | 98% | 33,460 psi | 85% | 2264 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>> | 86% | 29,211 psi | 75% | 2123 fps | 95% |
| Accurate 2495 | <<locked>> | 96% | 28,921 psi | 74% | 2198 fps | 95.5% |
| Alliant AR-Comp | 27.5 gr | 84% | 25,672 psi | 66% | 2083 fps | 95.8% |
| Alliant Reloder-10x | <<locked>> | 80% | 28,224 psi | 72% | 2106 fps | 96% |
| Hodgdon TrailBoss | 9.1 gr | 80% | 23,076 psi | 59% | 1312 fps | 100% |
| IMR 3031 | <<locked>> | 94% | 33,040 psi | 84% | 2277 fps | 95% |
| IMR 4198 | <<locked>> | 80% | 30,560 psi | 78% | 2113 fps | 97.6% |
| Norma 200 | <<locked>> | 80% | 31,778 psi | 81% | 2178 fps | 98% |
| ReloadSwiss RS 14 | 9.3 gr | 80% | 22,960 psi | 59% | 1345 fps | 100% |
| SNPE Vectan SP 3 | <<locked>> | 84% | 32,735 psi | 84% | 2192 fps | 95.3% |
| Vihtavuori N130 | <<locked>> | 80% | 27,601 psi | 70% | 2041 fps | 95.3% |
| Vihtavuori N133 | <<locked>> | 88% | 30,400 psi | 78% | 2113 fps | 95.1% |
| Vihtavuori N135 | <<locked>> | 94% | 29,631 psi | 76% | 2175 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 | Sellier & Bellot SP. IMR 3031 delivers the highest muzzle velocity at 2,320 fps; across all powders the maximum-charge window runs from 1,473 fps to 2,320 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, ReloadSwiss RS 14, Hodgdon TrailBoss rank at the top here: for .303 Savage with the .308 | 150gr | Sellier & Bellot SP 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.