Load Specifications
Load data in caliber .303 Savage with .308 | 150gr | Swift A-Frame 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, Alliant Reloder-10x and Vihtavuori N130.
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.
A valid access license is required to use the Personalized Load Calculator.
You can find more information in our FAQ: How can I use the Personalized Load Calculator?
Max Load - Barrel Length: 22"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2015 | <<locked>> | 94% | 34,650 psi | 88% | 2211 fps | 96.4% |
| ADI AR 2207 | <<locked>> | 82% | 33,707 psi | 86% | 2182 fps | 99.8% |
| Alliant AR-Comp | <<locked>> | 96% | 34,142 psi | 87% | 2267 fps | 98.5% |
| Alliant Reloder-10x | <<locked>> | 88% | 33,547 psi | 86% | 2201 fps | 97.3% |
| Alliant Reloder-7 | <<locked>> | 82% | 35,259 psi | 90% | 2175 fps | 98.1% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 30,748 psi | 79% | 1434 fps | 100% |
| IMR 4198 | <<locked>> | 86% | 34,243 psi | 87% | 2162 fps | 98.2% |
| Norma 200 | <<locked>> | 84% | 33,402 psi | 85% | 2185 fps | 98% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 30,414 psi | 78% | 1470 fps | 100% |
| Vihtavuori N120 | <<locked>> | 82% | 33,924 psi | 87% | 2152 fps | 100% |
| Vihtavuori N130 | <<locked>> | 90% | 34,809 psi | 89% | 2172 fps | 97.3% |
| Vihtavuori N133 | <<locked>> | 94% | 34,084 psi | 87% | 2162 fps | 95.8% |
| Vihtavuori N135ᴾ | <<locked>> | 100% | 33,141 psi | 85% | 2224 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>> | 90% | 30,618 psi | 78% | 2129 fps | 95% |
| ADI AR 2207 | <<locked>> | 80% | 31,662 psi | 81% | 2139 fps | 99.5% |
| Alliant AR-Comp | 26.9 gr | 88% | 27,021 psi | 69% | 2090 fps | 95.8% |
| Alliant Reloder-10x | 24.4 gr | 82% | 27,847 psi | 71% | 2070 fps | 95.2% |
| Alliant Reloder-7 | <<locked>> | 80% | 33,185 psi | 85% | 2133 fps | 97.6% |
| Hodgdon TrailBoss | <<locked>> | 80% | 22,655 psi | 58% | 1280 fps | 100% |
| IMR 4198 | <<locked>> | 80% | 28,863 psi | 74% | 2037 fps | 96.4% |
| Norma 200 | <<locked>> | 80% | 29,602 psi | 76% | 2103 fps | 96.8% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 22,553 psi | 58% | 1316 fps | 100% |
| Vihtavuori N120 | <<locked>> | 80% | 31,836 psi | 81% | 2113 fps | 99.9% |
| Vihtavuori N130 | 25.1 gr | 84% | 29,080 psi | 74% | 2051 fps | 95.3% |
| Vihtavuori N133 | <<locked>> | 92% | 32,169 psi | 82% | 2119 fps | 95.1% |
| Vihtavuori N135 | <<locked>> | 98% | 31,212 psi | 80% | 2182 fps | 95.1% |
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 35 powders for .303 Savage loaded with the .308 | 150gr | Swift A-Frame. IMR 3031 delivers the highest muzzle velocity at 2,277 fps; across all powders the maximum-charge window runs from 1,434 fps to 2,277 fps. Accurate 2495 gives the best case fill at 100 %, and 35 of the 35 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 1:16.0 twist; slower twists will usually not stabilise this weight. Accurate 2495, Hodgdon TrailBoss, Lovex D073.6 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, Alliant Reloder-10x, Vihtavuori N130 rank at the top here: for .303 Savage with the .308 | 150gr | Swift A-Frame they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, Accurate 2460, Accurate 2520, 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.