Load Specifications
Load data in caliber .303 Savage with .308 | 125gr | Remington PSP bullet and 9 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are 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 |
|---|---|---|---|---|---|---|
| ADI AR 2207 | <<locked>> | 88% | 34,925 psi | 89% | 2431 fps | 99% |
| Alliant AR-Compᴾ | <<locked>> | 100% | 33,562 psi | 86% | 2448 fps | 95.8% |
| Alliant Reloder-7 | <<locked>> | 86% | 34,896 psi | 89% | 2379 fps | 96% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 29,863 psi | 76% | 1578 fps | 100% |
| IMR 4198 | <<locked>> | 90% | 34,040 psi | 87% | 2362 fps | 96% |
| Norma 200 | <<locked>> | 90% | 34,650 psi | 88% | 2431 fps | 96.4% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 29,370 psi | 75% | 1614 fps | 100% |
| SNPE Vectan BA6 1/2 | <<locked>> | 82% | 33,939 psi | 87% | 2205 fps | 100% |
| Vihtavuori N120 | <<locked>> | 88% | 35,230 psi | 90% | 2405 fps | 99.7% |
Recommended = one of the top powders for this cartridge and bullet combination.
Start Load - Barrel Length: 22"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| ADI AR 2207 | <<locked>> | 80% | 27,340 psi | 70% | 2247 fps | 96.9% |
| Alliant AR-Comp | <<locked>> | 98% | 31,705 psi | 81% | 2402 fps | 95% |
| Alliant Reloder-7 | <<locked>> | 84% | 32,909 psi | 84% | 2336 fps | 95.3% |
| Hodgdon TrailBoss | 8.7 gr | 80% | 21,785 psi | 56% | 1407 fps | 100% |
| IMR 4198 | <<locked>> | 88% | 32,474 psi | 83% | 2323 fps | 95.4% |
| Norma 200 | <<locked>> | 88% | 32,663 psi | 83% | 2385 fps | 95.7% |
| ReloadSwiss RS 14 | 8.9 gr | 80% | 21,538 psi | 55% | 1444 fps | 100% |
| SNPE Vectan BA6 1/2 | <<locked>> | 80% | 32,198 psi | 82% | 2172 fps | 100% |
| Vihtavuori N120 | <<locked>> | 80% | 27,659 psi | 71% | 2228 fps | 98.1% |
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 17 powders for .303 Savage loaded with the .308 | 125gr | Remington PSP. Alliant AR-Comp delivers the highest muzzle velocity at 2,448 fps; across all powders the maximum-charge window runs from 1,578 fps to 2,448 fps. Alliant AR-Comp gives the best case fill at 100 %, and 17 of the 17 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (270 MPa), the top charges use 75–90 %, leaving at least 10 % headroom. The 125.0 gr projectile in 0.308" calls for a 1:15.0 twist; slower twists will usually not stabilise this weight. Alliant AR-Comp, 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. ReloadSwiss RS 14, Hodgdon TrailBoss rank at the top here: for .303 Savage with the .308 | 125gr | Remington PSP they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, Accurate 1680, Accurate 2015, Accurate LT-30 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.