Load Specifications
Load data in caliber 6 x 70 R with .243 | 100gr | Norma SSP bullet and 8 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Somchem S365, 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 |
|---|---|---|---|---|---|---|
| Alliant Reloder- TS 15.5 | <<locked>> | 82% | 34,040 psi | 90% | 2431 fps | 96.6% |
| Bofors RP3 | <<locked>> | 82% | 33,272 psi | 88% | 2428 fps | 96.5% |
| Hodgdon TrailBoss | <<locked>> | 98% | 33,881 psi | 90% | 1660 fps | 100% |
| ReloadSwiss RS 14 | <<locked>> | 96% | 32,895 psi | 87% | 1677 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 84% | 33,533 psi | 89% | 2500 fps | 98.1% |
| Rottweil R 903 | <<locked>> | 84% | 33,504 psi | 89% | 2425 fps | 96.3% |
| Somchem S365 | <<locked>> | 94% | 33,910 psi | 90% | 2507 fps | 97.5% |
| Vihtavuori N150 | <<locked>> | 84% | 32,924 psi | 87% | 2375 fps | 97.3% |
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 |
|---|---|---|---|---|---|---|
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 31,662 psi | 84% | 2375 fps | 95.8% |
| Bofors RP3 | <<locked>> | 80% | 30,937 psi | 82% | 2372 fps | 95.6% |
| Hodgdon TrailBoss | 8.8 gr | 80% | 25,802 psi | 68% | 1499 fps | 100% |
| ReloadSwiss RS 14 | 8.9 gr | 80% | 25,730 psi | 68% | 1529 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 29,312 psi | 78% | 2382 fps | 96.3% |
| Rottweil R 903 | <<locked>> | 82% | 31,183 psi | 83% | 2369 fps | 95.4% |
| Somchem S365 | 29.1 gr | 90% | 29,849 psi | 79% | 2402 fps | 95.8% |
| Vihtavuori N150 | <<locked>> | 80% | 28,834 psi | 76% | 2277 fps | 95.7% |
Recommended = one of the top powders for this cartridge and bullet combination.
This overview compares 8 powders for 6 x 70 R loaded with the .243 | 100gr | Norma SSP. Somchem S365 delivers the highest muzzle velocity at 2,507 fps; across all powders the maximum-charge window runs from 1,660 fps to 2,507 fps. Hodgdon TrailBoss gives the best case fill at 98 %, and 8 of the 8 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (260 MPa), the top charges use 87–90 %, 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. Somchem S365, ReloadSwiss RS 14, Hodgdon TrailBoss rank at the top here: for 6 x 70 R with the .243 | 100gr | Norma SSP 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.