Load Specifications
Load data in caliber .303 Savage with .308 | 150gr | Speer Magnum Tip Soft Point bullet and 13 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Alliant AR-Comp, Vihtavuori N130 and ReloadSwiss RS 14.
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>> | 92% | 33,997 psi | 87% | 2218 fps | 96.5% |
| Accurate 2495ᴾ | <<locked>> | 100% | 31,923 psi | 82% | 2257 fps | 96.4% |
| ADI AR 2207 | <<locked>> | 82% | 35,157 psi | 90% | 2224 fps | 100% |
| Alliant AR-Comp | <<locked>> | 94% | 33,663 psi | 86% | 2277 fps | 98.7% |
| Alliant Reloder-10x | <<locked>> | 88% | 35,114 psi | 90% | 2251 fps | 98% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 31,299 psi | 80% | 1460 fps | 100% |
| IMR 4198 | <<locked>> | 84% | 33,779 psi | 86% | 2172 fps | 98.4% |
| Norma 200 | <<locked>> | 84% | 35,027 psi | 89% | 2234 fps | 98.6% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 30,966 psi | 79% | 1493 fps | 100% |
| Vihtavuori N120 | <<locked>> | 82% | 35,375 psi | 90% | 2195 fps | 100% |
| Vihtavuori N130 | <<locked>> | 88% | 34,171 psi | 87% | 2178 fps | 97.4% |
| Vihtavuori N133 | <<locked>> | 94% | 35,259 psi | 90% | 2205 fps | 96.6% |
| Vihtavuori N135ᴾ | <<locked>> | 100% | 34,548 psi | 88% | 2274 fps | 96.8% |
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% | 30,226 psi | 77% | 2136 fps | 95.2% |
| Accurate 2495 | <<locked>> | 98% | 29,646 psi | 76% | 2208 fps | 95.6% |
| ADI AR 2207 | <<locked>> | 80% | 33,069 psi | 84% | 2182 fps | 99.8% |
| Alliant AR-Comp | 27.3 gr | 86% | 26,310 psi | 67% | 2090 fps | 95.9% |
| Alliant Reloder-10x | <<locked>> | 80% | 27,398 psi | 70% | 2077 fps | 95.4% |
| Hodgdon TrailBoss | <<locked>> | 80% | 23,076 psi | 59% | 1302 fps | 100% |
| IMR 4198 | <<locked>> | 80% | 30,052 psi | 77% | 2087 fps | 97.2% |
| Norma 200 | <<locked>> | 80% | 30,879 psi | 79% | 2146 fps | 97.5% |
| ReloadSwiss RS 14 | 9 gr | 80% | 22,597 psi | 58% | 1329 fps | 100% |
| Vihtavuori N120 | <<locked>> | 80% | 33,301 psi | 85% | 2156 fps | 100% |
| Vihtavuori N130 | 25.5 gr | 82% | 28,442 psi | 73% | 2051 fps | 95.4% |
| Vihtavuori N133 | <<locked>> | 90% | 31,488 psi | 80% | 2126 fps | 95.2% |
| Vihtavuori N135 | <<locked>> | 96% | 30,501 psi | 78% | 2182 fps | 95.3% |
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 37 powders for .303 Savage loaded with the .308 | 150gr | Speer Magnum Tip Soft Point. IMR 3031 delivers the highest muzzle velocity at 2,287 fps; across all powders the maximum-charge window runs from 1,460 fps to 2,287 fps. Accurate 2495 gives the best case fill at 100 %, and 37 of the 37 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (270 MPa), the top charges use 76–90 %, leaving at least 10 % headroom. The 150.0 gr projectile in 0.308" calls for a 1:6.0 twist; slower twists will usually not stabilise this weight. Accurate 2495, Accurate 4064, Hodgdon TrailBoss 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, Vihtavuori N130, ReloadSwiss RS 14 rank at the top here: for .303 Savage with the .308 | 150gr | Speer Magnum Tip Soft Point they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, Accurate 2460, Accurate 2520, Accurate 4064 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.