Load Specifications
Load data in caliber .303 Savage with .308 | 178gr | Remington SP Extended-Range bullet and 20 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are IMR 3031, Accurate 2495 and Alliant AR-Comp.
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>> | 88% | 35,012 psi | 89% | 2044 fps | 98.6% |
| Accurate 2460 | <<locked>> | 86% | 35,070 psi | 90% | 2064 fps | 95.7% |
| Accurate 2495 | <<locked>> | 96% | 33,620 psi | 86% | 2093 fps | 98.7% |
| Accurate 4064 | <<locked>> | 98% | 33,475 psi | 85% | 2100 fps | 96.2% |
| ADI AR 2219 | <<locked>> | 82% | 35,273 psi | 90% | 2073 fps | 97.1% |
| Alliant AR-Comp | <<locked>> | 90% | 34,171 psi | 87% | 2100 fps | 99.9% |
| Alliant Reloder-10x | <<locked>> | 82% | 33,692 psi | 86% | 2028 fps | 99.1% |
| Hodgdon H322 | <<locked>> | 84% | 34,606 psi | 88% | 2064 fps | 96.9% |
| Hodgdon H335 | <<locked>> | 84% | 34,882 psi | 89% | 2073 fps | 95.8% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 32,343 psi | 83% | 1339 fps | 100% |
| IMR 3031 | <<locked>> | 92% | 34,693 psi | 89% | 2119 fps | 97.8% |
| Norma 202 | <<locked>> | 92% | 35,172 psi | 90% | 2083 fps | 96% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 32,184 psi | 82% | 1368 fps | 100% |
| Rottweil R 901 | <<locked>> | 88% | 35,027 psi | 89% | 2041 fps | 95.7% |
| SNPE Vectan SP 3 | <<locked>> | 82% | 34,171 psi | 87% | 2024 fps | 97.7% |
| SNPE Vectan Tubal 5000 | <<locked>> | 96% | 34,867 psi | 89% | 2011 fps | 96.8% |
| Somchem S335 | <<locked>> | 90% | 35,012 psi | 89% | 2021 fps | 96.8% |
| Vihtavuori N130 | <<locked>> | 84% | 34,287 psi | 88% | 1991 fps | 99% |
| Vihtavuori N133 | <<locked>> | 88% | 33,808 psi | 86% | 1995 fps | 98.1% |
| Vihtavuori N135 | <<locked>> | 94% | 33,402 psi | 85% | 2067 fps | 98.4% |
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>> | 80% | 27,238 psi | 70% | 1886 fps | 96.2% |
| Accurate 2460 | <<locked>> | 84% | 33,112 psi | 85% | 2024 fps | 95% |
| Accurate 2495 | 27.1 gr | 86% | 24,091 psi | 62% | 1886 fps | 95.4% |
| Accurate 4064 | <<locked>> | 96% | 31,473 psi | 80% | 2060 fps | 95.5% |
| ADI AR 2219 | <<locked>> | 80% | 33,301 psi | 85% | 2034 fps | 96.4% |
| Alliant AR-Comp | 25 gr | 80% | 25,208 psi | 64% | 1896 fps | 97.8% |
| Alliant Reloder-10x | <<locked>> | 80% | 31,734 psi | 81% | 1988 fps | 98.7% |
| Hodgdon H322 | <<locked>> | 80% | 30,487 psi | 78% | 1975 fps | 95.3% |
| Hodgdon H335 | <<locked>> | 82% | 32,634 psi | 83% | 2028 fps | 95% |
| Hodgdon TrailBoss | <<locked>> | 80% | 23,772 psi | 61% | 1191 fps | 100% |
| IMR 3031 | 26.8 gr | 86% | 28,834 psi | 74% | 1988 fps | 95.6% |
| Norma 202 | <<locked>> | 90% | 33,170 psi | 85% | 2044 fps | 95.4% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 23,772 psi | 61% | 1224 fps | 100% |
| Rottweil R 901 | <<locked>> | 86% | 33,040 psi | 84% | 2001 fps | 95% |
| SNPE Vectan SP 3 | <<locked>> | 80% | 32,126 psi | 82% | 1985 fps | 97.1% |
| SNPE Vectan Tubal 5000 | <<locked>> | 92% | 31,038 psi | 79% | 1939 fps | 95.5% |
| Somchem S335 | <<locked>> | 86% | 30,908 psi | 79% | 1942 fps | 95.4% |
| Vihtavuori N130 | <<locked>> | 80% | 30,443 psi | 78% | 1916 fps | 98.1% |
| Vihtavuori N133 | <<locked>> | 80% | 26,498 psi | 68% | 1837 fps | 95.5% |
| Vihtavuori N135 | <<locked>> | 84% | 24,642 psi | 63% | 1864 fps | 95% |
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 20 powders for .303 Savage loaded with the .308 | 178gr | Remington SP Extended-Range. IMR 3031 delivers the highest muzzle velocity at 2,119 fps; across all powders the maximum-charge window runs from 1,339 fps to 2,119 fps. Hodgdon TrailBoss gives the best case fill at 100 %, and 20 of the 20 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (270 MPa), the top charges use 82–90 %, leaving at least 10 % headroom. The 178.0 gr projectile in 0.308" calls for a 1:6.0 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. IMR 3031, Accurate 2495, Alliant AR-Comp rank at the top here: for .303 Savage with the .308 | 178gr | Remington SP Extended-Range 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.