Load Specifications
Load data in caliber .303 Savage with .308 | 150gr | Barnes X FN bullet and 11 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>> | 90% | 33,924 psi | 87% | 2162 fps | 95.9% |
| Accurate 2495ᴾ | <<locked>> | 100% | 33,968 psi | 87% | 2244 fps | 96.5% |
| Alliant AR-Comp | <<locked>> | 94% | 35,041 psi | 89% | 2254 fps | 98.6% |
| Alliant Reloder-10x | <<locked>> | 86% | 34,519 psi | 88% | 2188 fps | 97.4% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 31,894 psi | 81% | 1434 fps | 100% |
| IMR 4198 | <<locked>> | 84% | 34,751 psi | 89% | 2142 fps | 98.2% |
| Norma 200 | <<locked>> | 82% | 35,143 psi | 90% | 2182 fps | 98.2% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 31,734 psi | 81% | 1470 fps | 100% |
| Vihtavuori N130 | <<locked>> | 86% | 33,634 psi | 86% | 2116 fps | 96.8% |
| Vihtavuori N133 | <<locked>> | 92% | 34,693 psi | 89% | 2146 fps | 95.8% |
| Vihtavuori N135 | <<locked>> | 98% | 33,881 psi | 87% | 2208 fps | 95.9% |
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% | 32,024 psi | 82% | 2123 fps | 95.2% |
| Accurate 2495 | <<locked>> | 96% | 30,153 psi | 77% | 2165 fps | 95.1% |
| Alliant AR-Comp | 25.4 gr | 84% | 26,687 psi | 68% | 2044 fps | 95.3% |
| Alliant Reloder-10x | <<locked>> | 80% | 29,370 psi | 75% | 2070 fps | 95.6% |
| Hodgdon TrailBoss | 8.4 gr | 80% | 23,714 psi | 61% | 1280 fps | 100% |
| IMR 4198 | <<locked>> | 80% | 31,270 psi | 80% | 2064 fps | 97.1% |
| Norma 200 | <<locked>> | 80% | 33,185 psi | 85% | 2139 fps | 97.7% |
| ReloadSwiss RS 14 | 8.6 gr | 80% | 23,757 psi | 61% | 1312 fps | 100% |
| Vihtavuori N130 | <<locked>> | 82% | 30,095 psi | 77% | 2037 fps | 95.5% |
| Vihtavuori N133 | <<locked>> | 90% | 32,895 psi | 84% | 2106 fps | 95.1% |
| Vihtavuori N135 | <<locked>> | 96% | 32,068 psi | 82% | 2165 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 11 powders for .303 Savage loaded with the .308 | 150gr | Barnes X FN. Alliant AR-Comp delivers the highest muzzle velocity at 2,254 fps; across all powders the maximum-charge window runs from 1,434 fps to 2,254 fps. Accurate 2495 gives the best case fill at 100 %, and 11 of the 11 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (270 MPa), the top charges use 81–90 %, leaving at least 10 % headroom. The 150.0 gr projectile in 0.308" calls for a 1:15.5 twist; slower twists will usually not stabilise this weight. 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 | Barnes X FN 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.