Load Specifications
Load data in caliber .303 Savage with .308 | 170gr | Sierra Pro-Hunter bullet and 18 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are IMR 3031, Vihtavuori N135 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>> | 90% | 35,433 psi | 90% | 2103 fps | 98.3% |
| Accurate 2495 | <<locked>> | 98% | 34,011 psi | 87% | 2152 fps | 98.4% |
| Accurate 4064ᴾ | <<locked>> | 100% | 33,823 psi | 86% | 2159 fps | 95.7% |
| ADI AR 2219 | <<locked>> | 82% | 34,127 psi | 87% | 2100 fps | 96.1% |
| Alliant AR-Comp | <<locked>> | 92% | 34,911 psi | 89% | 2162 fps | 99.8% |
| Alliant Reloder-10x | <<locked>> | 84% | 34,200 psi | 87% | 2087 fps | 98.9% |
| Baschieri & Pellagri 106 | <<locked>> | 82% | 34,867 psi | 89% | 2031 fps | 96.9% |
| Hodgdon H322 | <<locked>> | 88% | 34,809 psi | 89% | 2113 fps | 96.3% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 31,952 psi | 82% | 1368 fps | 100% |
| IMR 3031 | <<locked>> | 96% | 34,113 psi | 87% | 2152 fps | 97% |
| IMR 4198 | <<locked>> | 82% | 34,505 psi | 88% | 2047 fps | 99.4% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 31,749 psi | 81% | 1398 fps | 100% |
| SNPE Vectan SP 3 | <<locked>> | 84% | 35,099 psi | 90% | 2090 fps | 97.4% |
| SNPE Vectan Tubal 5000 | <<locked>> | 96% | 33,750 psi | 86% | 2034 fps | 95.8% |
| Somchem S335 | <<locked>> | 90% | 33,794 psi | 86% | 2044 fps | 95.8% |
| Vihtavuori N130 | <<locked>> | 86% | 34,461 psi | 88% | 2044 fps | 98.7% |
| Vihtavuori N133 | <<locked>> | 92% | 33,852 psi | 86% | 2044 fps | 97.7% |
| Vihtavuori N135 | <<locked>> | 96% | 34,098 psi | 87% | 2126 fps | 98.1% |
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% | 25,976 psi | 66% | 1900 fps | 95% |
| Accurate 2495 | <<locked>> | 90% | 26,179 psi | 67% | 1985 fps | 95.8% |
| Accurate 4064 | <<locked>> | 98% | 31,850 psi | 81% | 2119 fps | 95% |
| ADI AR 2219 | <<locked>> | 80% | 31,879 psi | 81% | 2051 fps | 95.2% |
| Alliant AR-Comp | 25 gr | 80% | 24,134 psi | 62% | 1906 fps | 96.6% |
| Alliant Reloder-10x | <<locked>> | 80% | 30,284 psi | 77% | 2008 fps | 97.9% |
| Baschieri & Pellagri 106 | <<locked>> | 80% | 32,706 psi | 84% | 1991 fps | 96.2% |
| Hodgdon H322 | <<locked>> | 86% | 32,808 psi | 84% | 2073 fps | 95.6% |
| Hodgdon TrailBoss | <<locked>> | 80% | 23,453 psi | 60% | 1217 fps | 100% |
| IMR 3031 | 27.8 gr | 92% | 30,371 psi | 78% | 2070 fps | 95.6% |
| IMR 4198 | <<locked>> | 80% | 32,489 psi | 83% | 2005 fps | 99.1% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 23,438 psi | 60% | 1250 fps | 100% |
| SNPE Vectan SP 3 | <<locked>> | 80% | 31,111 psi | 79% | 2008 fps | 96.1% |
| SNPE Vectan Tubal 5000 | <<locked>> | 94% | 31,575 psi | 81% | 1991 fps | 95% |
| Somchem S335 | <<locked>> | 88% | 31,618 psi | 81% | 2001 fps | 95% |
| Vihtavuori N130 | <<locked>> | 80% | 28,834 psi | 74% | 1929 fps | 97.1% |
| Vihtavuori N133 | <<locked>> | 84% | 27,035 psi | 69% | 1896 fps | 95.1% |
| Vihtavuori N135 | 26.9 gr | 88% | 26,701 psi | 68% | 1962 fps | 95.4% |
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 18 powders for .303 Savage loaded with the .308 | 170gr | Sierra Pro-Hunter. Alliant AR-Comp delivers the highest muzzle velocity at 2,162 fps; across all powders the maximum-charge window runs from 1,368 fps to 2,162 fps. Accurate 4064 gives the best case fill at 100 %, and 18 of the 18 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 170.0 gr projectile in 0.308" calls for a 1:6.0 twist; slower twists will usually not stabilise this weight. Accurate 4064, 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, Vihtavuori N135, Alliant AR-Comp rank at the top here: for .303 Savage with the .308 | 170gr | Sierra Pro-Hunter 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.