Load Specifications
Load data in caliber 6 x 70 R with .243 | 100gr | Sierra Pro-Hunter bullet and 10 powders. The key underlying parameters are shown in the table above.
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 |
|---|---|---|---|---|---|---|
| Alliant Reloder- TS 15.5 | <<locked>> | 82% | 33,402 psi | 89% | 2415 fps | 96.4% |
| Bofors RP3 | <<locked>> | 82% | 32,996 psi | 88% | 2418 fps | 96.4% |
| Hodgdon TrailBoss | <<locked>> | 98% | 33,808 psi | 90% | 1657 fps | 100% |
| ReloadSwiss RS 14 | <<locked>> | 98% | 34,069 psi | 90% | 1696 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 84% | 33,359 psi | 88% | 2493 fps | 98% |
| Rottweil R 903 | <<locked>> | 84% | 32,938 psi | 87% | 2408 fps | 96% |
| SNPE Vectan Tubal 5000 | <<locked>> | 82% | 33,968 psi | 90% | 2339 fps | 99.5% |
| Somchem S355 | <<locked>> | 84% | 34,069 psi | 90% | 2418 fps | 96.1% |
| Somchem S365 | <<locked>> | 94% | 33,750 psi | 90% | 2500 fps | 97.4% |
| Vihtavuori N150 | <<locked>> | 84% | 32,401 psi | 86% | 2362 fps | 97% |
Start Load - Barrel Length: 25.6"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 31,401 psi | 83% | 2365 fps | 95.6% |
| Bofors RP3 | <<locked>> | 80% | 30,705 psi | 81% | 2362 fps | 95.5% |
| Hodgdon TrailBoss | <<locked>> | 80% | 25,643 psi | 68% | 1493 fps | 100% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 25,976 psi | 69% | 1532 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 29,138 psi | 77% | 2372 fps | 96.1% |
| Rottweil R 903 | <<locked>> | 82% | 30,951 psi | 82% | 2362 fps | 95.2% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 31,908 psi | 85% | 2293 fps | 99.2% |
| Somchem S355 | <<locked>> | 82% | 32,039 psi | 85% | 2372 fps | 95.3% |
| Somchem S365 | <<locked>> | 90% | 29,704 psi | 79% | 2392 fps | 95.6% |
| Vihtavuori N150 | <<locked>> | 80% | 28,616 psi | 76% | 2270 fps | 95.5% |
This overview compares 10 powders for 6 x 70 R loaded with the .243 | 100gr | Sierra Pro-Hunter. Somchem S365 delivers the highest muzzle velocity at 2,500 fps; across all powders the maximum-charge window runs from 1,657 fps to 2,500 fps. Hodgdon TrailBoss gives the best case fill at 98 %, and 10 of the 10 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (260 MPa), the top charges use 86–90 %, leaving at least 10 % headroom. The 100.0 gr projectile in 0.243" calls for a 1:10.5 twist; slower twists will usually not stabilise this weight. Always begin at the start load and work up in small increments while checking case and primer for pressure signs.