Load Specifications
Load data in caliber .300 AAC Blackout with .308 | 135gr | Sierra VarmintKing bullet and 7 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Vihtavuori N110 and ADI AR 2205.
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: 16"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| ADI AR 2205 | <<locked>> | 96% | 45,368 psi | 89% | 1909 fps | 97.7% |
| Hodgdon LilGun | <<locked>> | 92% | 45,905 psi | 90% | 2060 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 25,005 psi | 49% | 1171 fps | 100% |
| Lovex S040 | <<locked>> | 88% | 44,251 psi | 87% | 1909 fps | 99.9% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 24,018 psi | 47% | 1194 fps | 100% |
| SNPE Vectan BA6 1/2ᴾ | <<locked>> | 100% | 33,707 psi | 66% | 1775 fps | 100% |
| Vihtavuori N110ᴾ | <<locked>> | 100% | 42,757 psi | 84% | 1942 fps | 100% |
Recommended = one of the top powders for this cartridge and bullet combination.
Start Load - Barrel Length: 16"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| ADI AR 2205 | 14.9 gr | 88% | 35,505 psi | 70% | 1772 fps | 95.4% |
| Hodgdon LilGun | <<locked>> | 80% | 30,487 psi | 60% | 1837 fps | 99.2% |
| Hodgdon TrailBoss | <<locked>> | 80% | 18,159 psi | 36% | 1043 fps | 100% |
| Lovex S040 | <<locked>> | 80% | 34,853 psi | 69% | 1775 fps | 99% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 17,564 psi | 35% | 1066 fps | 100% |
| SNPE Vectan BA6 1/2 | <<locked>> | 80% | 20,204 psi | 40% | 1496 fps | 96.5% |
| Vihtavuori N110 | 12.2 gr | 80% | 24,250 psi | 48% | 1631 fps | 96.8% |
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 7 powders for .300 AAC Blackout loaded with the .308 | 135gr | Sierra VarmintKing. Hodgdon LilGun delivers the highest muzzle velocity at 2,060 fps; across all powders the maximum-charge window runs from 1,171 fps to 2,060 fps. Hodgdon TrailBoss gives the best case fill at 100 %, and 7 of the 7 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (350 MPa), the top charges use 47–90 %, leaving at least 10 % headroom. The 135.0 gr projectile in 0.308" calls for a 1:17.0 twist; slower twists will usually not stabilise this weight. Hodgdon TrailBoss, ReloadSwiss RS 14, SNPE Vectan BA6 1/2 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. Vihtavuori N110, ADI AR 2205, Lovex S053 rank at the top here: for .300 AAC Blackout with the .308 | 135gr | Sierra VarmintKing they combine a high case fill with complete burn and sit in the upper velocity band. Hodgdon TrailBoss, ReloadSwiss RS 14 stay subsonic at start load. Always begin at the start load and work up in small increments while checking case and primer for pressure signs.