Load Specifications
Load data in caliber .303 Savage with .308 | 150gr | RWS TMR 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% | 33,953 psi | 87% | 2215 fps | 96.5% |
| Accurate 2495ᴾ | <<locked>> | 100% | 31,560 psi | 81% | 2247 fps | 96.2% |
| ADI AR 2207 | <<locked>> | 82% | 35,085 psi | 90% | 2221 fps | 99.9% |
| Alliant AR-Comp | <<locked>> | 94% | 33,373 psi | 85% | 2267 fps | 98.6% |
| Alliant Reloder-10x | <<locked>> | 88% | 34,737 psi | 89% | 2241 fps | 97.9% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 31,096 psi | 79% | 1453 fps | 100% |
| IMR 4198 | <<locked>> | 86% | 35,389 psi | 90% | 2201 fps | 98.7% |
| Norma 200 | <<locked>> | 84% | 35,027 psi | 89% | 2231 fps | 98.6% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 30,792 psi | 79% | 1486 fps | 100% |
| Vihtavuori N120 | <<locked>> | 82% | 35,302 psi | 90% | 2192 fps | 100% |
| Vihtavuori N130 | <<locked>> | 88% | 33,837 psi | 86% | 2169 fps | 97.3% |
| Vihtavuori N133 | <<locked>> | 94% | 35,288 psi | 90% | 2205 fps | 96.6% |
| Vihtavuori N135ᴾ | <<locked>> | 100% | 34,258 psi | 87% | 2264 fps | 96.6% |
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% | 29,878 psi | 76% | 2126 fps | 95% |
| Accurate 2495 | <<locked>> | 98% | 29,356 psi | 75% | 2198 fps | 95.4% |
| ADI AR 2207 | <<locked>> | 80% | 32,663 psi | 83% | 2172 fps | 99.8% |
| Alliant AR-Comp | 27.2 gr | 86% | 26,266 psi | 67% | 2087 fps | 95.7% |
| Alliant Reloder-10x | <<locked>> | 80% | 27,340 psi | 70% | 2070 fps | 95.3% |
| Hodgdon TrailBoss | <<locked>> | 80% | 22,858 psi | 58% | 1296 fps | 100% |
| IMR 4198 | <<locked>> | 80% | 29,979 psi | 77% | 2083 fps | 97.2% |
| Norma 200 | <<locked>> | 80% | 30,850 psi | 79% | 2142 fps | 97.5% |
| ReloadSwiss RS 14 | 9 gr | 80% | 22,727 psi | 58% | 1329 fps | 100% |
| Vihtavuori N120 | <<locked>> | 80% | 32,895 psi | 84% | 2146 fps | 100% |
| Vihtavuori N130 | 25.3 gr | 82% | 28,152 psi | 72% | 2041 fps | 95.2% |
| Vihtavuori N133 | <<locked>> | 90% | 31,198 psi | 80% | 2116 fps | 95.1% |
| Vihtavuori N135 | <<locked>> | 96% | 30,545 psi | 78% | 2182 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 13 powders for .303 Savage loaded with the .308 | 150gr | RWS TMR. Alliant AR-Comp delivers the highest muzzle velocity at 2,267 fps; across all powders the maximum-charge window runs from 1,453 fps to 2,267 fps. Accurate 2495 gives the best case fill at 100 %, and 13 of the 13 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (270 MPa), the top charges use 79–90 %, 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, 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, Vihtavuori N130, ReloadSwiss RS 14 rank at the top here: for .303 Savage with the .308 | 150gr | RWS TMR 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.