Load Specifications
Load data in caliber .303 Savage with .308 | 85gr | Sierra Sports Master bullet and 6 powders. The key underlying parameters are shown in the table above.
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 |
|---|---|---|---|---|---|---|
| ADI AR 2207 | <<locked>> | 94% | 34,780 psi | 89% | 3018 fps | 96.5% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 27,369 psi | 70% | 1995 fps | 100% |
| Lovex S053 | <<locked>> | 86% | 34,026 psi | 87% | 2904 fps | 98.1% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 26,310 psi | 67% | 2034 fps | 100% |
| SNPE Vectan BA6 1/2 | <<locked>> | 88% | 33,591 psi | 86% | 2789 fps | 100% |
| Vihtavuori N120 | <<locked>> | 94% | 35,273 psi | 90% | 2992 fps | 97.8% |
Start Load - Barrel Length: 22"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| ADI AR 2207 | <<locked>> | 92% | 32,401 psi | 83% | 2949 fps | 95.6% |
| Hodgdon TrailBoss | <<locked>> | 80% | 19,421 psi | 50% | 1778 fps | 100% |
| Lovex S053 | <<locked>> | 80% | 27,949 psi | 71% | 2726 fps | 95.9% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 18,739 psi | 48% | 1814 fps | 100% |
| SNPE Vectan BA6 1/2 | <<locked>> | 80% | 26,745 psi | 68% | 2615 fps | 100% |
| Vihtavuori N120 | <<locked>> | 88% | 29,095 psi | 74% | 2818 fps | 95.6% |
ᴾ possible press load - work up slowly to this load while watching for signs of excessive pressure.
This overview compares 12 powders for .303 Savage loaded with the .308 | 85gr | Sierra Sports Master. ADI AR 2207 delivers the highest muzzle velocity at 3,018 fps; across all powders the maximum-charge window runs from 1,995 fps to 3,018 fps. Hodgdon TrailBoss gives the best case fill at 100 %, and 12 of the 12 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (270 MPa), the top charges use 67–90 %, 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. As outliers, Accurate 1680, Alliant Reloder-7, IMR 4198 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.