Load Specifications
Load data in caliber .300 AAC Blackout with .308 | 178gr | TWENTY-NINE SILENTIO bullet and 9 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Hodgdon LilGun, Lovex S040 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.
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Max Load - Barrel Length: 16"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate No. 11 FS | <<locked>> | 96% | 45,701 psi | 90% | 1591 fps | 96.8% |
| ADI AR 2205 | <<locked>> | 96% | 44,048 psi | 87% | 1519 fps | 98.2% |
| Hodgdon LilGun | <<locked>> | 92% | 43,700 psi | 86% | 1637 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 24,903 psi | 49% | 922 fps | 100% |
| Lovex S040 | <<locked>> | 90% | 45,556 psi | 90% | 1539 fps | 100% |
| Lovex S053ᴾ | <<locked>> | 100% | 34,447 psi | 68% | 1483 fps | 96.2% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 24,047 psi | 47% | 942 fps | 100% |
| SNPE Vectan BA6 1/2ᴾ | <<locked>> | 100% | 32,503 psi | 64% | 1411 fps | 100% |
| Vihtavuori N110ᴾ | <<locked>> | 100% | 41,539 psi | 82% | 1545 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 |
|---|---|---|---|---|---|---|
| Accurate No. 11 FS | <<locked>> | 92% | 39,697 psi | 78% | 1529 fps | 95.4% |
| ADI AR 2205 | 10.9 gr | 86% | 32,648 psi | 64% | 1385 fps | 95.5% |
| Hodgdon LilGun | 11.1 gr | 80% | 29,472 psi | 58% | 1470 fps | 99.6% |
| Hodgdon TrailBoss | <<locked>> | 80% | 18,072 psi | 36% | 820 fps | 100% |
| Lovex S040 | 9.5 gr | 80% | 33,997 psi | 67% | 1411 fps | 99.4% |
| Lovex S053 | <<locked>> | 96% | 31,386 psi | 62% | 1440 fps | 95.2% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 17,622 psi | 35% | 843 fps | 100% |
| SNPE Vectan BA6 1/2 | <<locked>> | 80% | 19,464 psi | 38% | 1191 fps | 97.3% |
| Vihtavuori N110 | <<locked>> | 80% | 23,322 psi | 46% | 1299 fps | 97.5% |
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 9 powders for .300 AAC Blackout loaded with the .308 | 178gr | TWENTY-NINE SILENTIO. Hodgdon LilGun delivers the highest muzzle velocity at 1,637 fps; across all powders the maximum-charge window runs from 922 fps to 1,637 fps. Hodgdon TrailBoss gives the best case fill at 100 %, and 9 of the 9 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 178.0 gr projectile in 0.308" calls for a 1:11.0 twist; slower twists will usually not stabilise this weight. Hodgdon TrailBoss, Lovex S053, 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. Hodgdon LilGun, Lovex S040, ADI AR 2205 rank at the top here: for .300 AAC Blackout with the .308 | 178gr | TWENTY-NINE SILENTIO 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.