Load Specifications
Load data in caliber 6 x 70 R with .243 | 88gr | Berger Varmint bullet and 9 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 |
|---|---|---|---|---|---|---|
| Accurate 2495 | <<locked>> | 84% | 33,837 psi | 90% | 2556 fps | 99.7% |
| Accurate 4064 | <<locked>> | 86% | 33,968 psi | 90% | 2579 fps | 98.3% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 33,953 psi | 90% | 1765 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 34,084 psi | 90% | 1808 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 88% | 33,982 psi | 90% | 2631 fps | 96.2% |
| SNPE Vectan Tubal 5000 | <<locked>> | 84% | 32,416 psi | 86% | 2444 fps | 98.3% |
| Vihtavuori N135 | <<locked>> | 82% | 32,213 psi | 85% | 2510 fps | 99.5% |
| Vihtavuori N140 | <<locked>> | 82% | 33,663 psi | 89% | 2516 fps | 98.1% |
| Vihtavuori N540 | <<locked>> | 82% | 32,227 psi | 85% | 2493 fps | 97.1% |
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 |
|---|---|---|---|---|---|---|
| Accurate 2495 | <<locked>> | 80% | 29,747 psi | 79% | 2457 fps | 99.1% |
| Accurate 4064 | <<locked>> | 80% | 28,181 psi | 75% | 2431 fps | 96.3% |
| Hodgdon TrailBoss | 8.6 gr | 80% | 24,976 psi | 66% | 1578 fps | 100% |
| ReloadSwiss RS 14 | 8.8 gr | 80% | 25,193 psi | 67% | 1617 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 86% | 31,749 psi | 84% | 2566 fps | 95.1% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 28,587 psi | 76% | 2346 fps | 97.1% |
| Vihtavuori N135 | <<locked>> | 80% | 30,197 psi | 80% | 2461 fps | 99.1% |
| Vihtavuori N140 | <<locked>> | 80% | 31,314 psi | 83% | 2457 fps | 97.4% |
| Vihtavuori N540 | <<locked>> | 80% | 30,327 psi | 80% | 2448 fps | 96.5% |
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 6 x 70 R loaded with the .243 | 88gr | Berger Varmint. ReloadSwiss RS 60 delivers the highest muzzle velocity at 2,631 fps; across all powders the maximum-charge window runs from 1,765 fps to 2,631 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 (260 MPa), the top charges use 85–90 %, leaving at least 10 % headroom. The 88.0 gr projectile in 0.243" calls for a 1:9.5 twist; slower twists will usually not stabilise this weight. Hodgdon TrailBoss, 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. ReloadSwiss RS 14, Hodgdon TrailBoss rank at the top here: for 6 x 70 R with the .243 | 88gr | Berger Varmint 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.