Load Specifications
Load data in caliber 6 x 70 R with .243 | 65gr | Berger ND 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 |
|---|---|---|---|---|---|---|
| Accurate 2015 | <<locked>> | 82% | 33,808 psi | 90% | 2877 fps | 97.7% |
| Accurate 2495 | <<locked>> | 88% | 31,749 psi | 84% | 2884 fps | 97.5% |
| Alliant AR-Comp | <<locked>> | 84% | 32,851 psi | 87% | 2946 fps | 99.5% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 32,619 psi | 87% | 2060 fps | 100% |
| IMR 3031 | <<locked>> | 86% | 33,692 psi | 89% | 2976 fps | 96.9% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 32,866 psi | 87% | 2113 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 90% | 33,794 psi | 90% | 2835 fps | 96% |
| Somchem S335 | <<locked>> | 84% | 33,968 psi | 90% | 2844 fps | 95.9% |
| Vihtavuori N133 | <<locked>> | 82% | 32,256 psi | 86% | 2805 fps | 97.1% |
| Vihtavuori N135 | <<locked>> | 88% | 32,706 psi | 87% | 2904 fps | 97.6% |
Start Load - Barrel Length: 25.6"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2015 | <<locked>> | 80% | 31,546 psi | 84% | 2815 fps | 96.9% |
| Accurate 2495 | <<locked>> | 82% | 25,904 psi | 69% | 2710 fps | 95% |
| Alliant AR-Comp | <<locked>> | 80% | 28,848 psi | 77% | 2828 fps | 98.5% |
| Hodgdon TrailBoss | <<locked>> | 80% | 24,091 psi | 64% | 1850 fps | 100% |
| IMR 3031 | <<locked>> | 84% | 31,444 psi | 83% | 2910 fps | 95.9% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 24,091 psi | 64% | 1896 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 88% | 31,604 psi | 84% | 2776 fps | 95.2% |
| Somchem S335 | <<locked>> | 82% | 31,792 psi | 84% | 2785 fps | 95% |
| Vihtavuori N133 | <<locked>> | 80% | 30,110 psi | 80% | 2746 fps | 96.2% |
| Vihtavuori N135 | <<locked>> | 82% | 27,050 psi | 72% | 2733 fps | 95.2% |
ᴾ possible press load - work up slowly to this load while watching for signs of excessive pressure.
This overview compares 22 powders for 6 x 70 R loaded with the .243 | 65gr | Berger ND. IMR 3031 delivers the highest muzzle velocity at 2,976 fps; across all powders the maximum-charge window runs from 2,060 fps to 2,976 fps. Hodgdon TrailBoss gives the best case fill at 100 %, and 22 of the 22 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (260 MPa), the top charges use 84–90 %, leaving at least 10 % headroom. The 65.0 gr projectile in 0.243" calls for a 1:11.5 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. As outliers, Accurate 2520, Accurate 4064, Hodgdon BL-C2 burn incompletely and react more sensitively to barrel length and temperature. Always begin at the start load and work up in small increments while checking case and primer for pressure signs.