Load Specifications
Load data in caliber .303 Savage with .310 | 108gr | Barnes MPG bullet and 8 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>> | 92% | 34,766 psi | 89% | 2612 fps | 97.7% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 28,863 psi | 74% | 1693 fps | 100% |
| IMR 4227 | <<locked>> | 82% | 33,460 psi | 85% | 2467 fps | 95.7% |
| Lovex S053 | <<locked>> | 84% | 34,418 psi | 88% | 2503 fps | 99% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 28,224 psi | 72% | 1732 fps | 100% |
| ReloadSwiss RS 36 | <<locked>> | 84% | 34,258 psi | 87% | 2533 fps | 95.8% |
| SNPE Vectan BA6 1/2 | <<locked>> | 86% | 34,084 psi | 87% | 2392 fps | 100% |
| Vihtavuori N120 | <<locked>> | 92% | 35,143 psi | 90% | 2585 fps | 98.7% |
Start Load - Barrel Length: 22"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| ADI AR 2207 | <<locked>> | 86% | 29,022 psi | 74% | 2464 fps | 95.6% |
| Hodgdon TrailBoss | <<locked>> | 80% | 21,060 psi | 54% | 1512 fps | 100% |
| IMR 4227 | <<locked>> | 80% | 31,459 psi | 80% | 2418 fps | 95% |
| Lovex S053 | <<locked>> | 80% | 30,501 psi | 78% | 2408 fps | 98.1% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 20,392 psi | 52% | 1542 fps | 100% |
| ReloadSwiss RS 36 | <<locked>> | 82% | 31,952 psi | 82% | 2477 fps | 95% |
| SNPE Vectan BA6 1/2 | <<locked>> | 80% | 28,906 psi | 74% | 2280 fps | 100% |
| Vihtavuori N120 | <<locked>> | 82% | 26,237 psi | 67% | 2349 fps | 95.7% |
ᴾ possible press load - work up slowly to this load while watching for signs of excessive pressure.
This overview compares 8 powders for .303 Savage loaded with the .310 | 108gr | Barnes MPG. ADI AR 2207 delivers the highest muzzle velocity at 2,612 fps; across all powders the maximum-charge window runs from 1,693 fps to 2,612 fps. Hodgdon TrailBoss gives the best case fill at 100 %, and 8 of the 8 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (270 MPa), the top charges use 72–90 %, leaving at least 10 % headroom. The 108.0 gr projectile in 0.31" calls for a 1:14.5 twist; slower twists will usually not stabilise this weight. 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. Always begin at the start load and work up in small increments while checking case and primer for pressure signs.