Load Specifications
Load data in caliber 6 x 70 R with .243 | 90gr | Impala RNFP KO bullet and 4 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are ReloadSwiss RS 14 and Hodgdon TrailBoss.
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: 25.6"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Hodgdon TrailBoss | <<locked>> | 98% | 33,591 psi | 89% | 1719 fps | 100% |
| ReloadSwiss RS 14 | <<locked>> | 98% | 33,895 psi | 90% | 1759 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 82% | 33,373 psi | 89% | 2408 fps | 98.6% |
| Vihtavuori N150 | <<locked>> | 86% | 33,634 psi | 89% | 2467 fps | 95.8% |
Recommended = one of the top powders for this cartridge and bullet combination.
Start Load - Barrel Length: 25.6"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Hodgdon TrailBoss | 8.4 gr | 80% | 25,744 psi | 68% | 1552 fps | 100% |
| ReloadSwiss RS 14 | 8.6 gr | 80% | 26,121 psi | 69% | 1594 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 31,444 psi | 83% | 2362 fps | 98.1% |
| Vihtavuori N150 | <<locked>> | 84% | 31,749 psi | 84% | 2421 fps | 95.1% |
Recommended = one of the top powders for this cartridge and bullet combination.
This overview compares 4 powders for 6 x 70 R loaded with the .243 | 90gr | Impala RNFP KO. Vihtavuori N150 delivers the highest muzzle velocity at 2,467 fps; across all powders the maximum-charge window runs from 1,719 fps to 2,467 fps. Hodgdon TrailBoss gives the best case fill at 98 %, and 4 of the 4 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (260 MPa), the top charges use 89–90 %, leaving at least 10 % headroom. The 90.0 gr projectile in 0.243" calls for a 1:8.5 twist; slower twists will usually not stabilise this weight. ReloadSwiss RS 14, Hodgdon TrailBoss rank at the top here: for 6 x 70 R with the .243 | 90gr | Impala RNFP KO 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.