Load Specifications
Load data in caliber 6 x 70 R with .243 | 62gr | Barnes Varmint Grenade FB bullet and 7 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Accurate 2495, 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 2015 | <<locked>> | 84% | 32,793 psi | 87% | 2890 fps | 96.5% |
| Accurate 2495 | <<locked>> | 92% | 32,605 psi | 86% | 2953 fps | 97% |
| Alliant AR-Comp | <<locked>> | 86% | 32,039 psi | 85% | 2963 fps | 98.7% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 32,097 psi | 85% | 2077 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 31,894 psi | 85% | 2123 fps | 100% |
| Vihtavuori N133 | <<locked>> | 86% | 33,489 psi | 89% | 2874 fps | 96.6% |
| Vihtavuori N135 | <<locked>> | 92% | 33,823 psi | 90% | 2972 fps | 97.2% |
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 2015 | <<locked>> | 82% | 30,835 psi | 82% | 2835 fps | 95.8% |
| Accurate 2495 | 28.4 gr | 88% | 28,311 psi | 75% | 2831 fps | 95.3% |
| Alliant AR-Comp | <<locked>> | 80% | 26,411 psi | 70% | 2779 fps | 96.4% |
| Hodgdon TrailBoss | 8.9 gr | 80% | 23,656 psi | 63% | 1867 fps | 100% |
| ReloadSwiss RS 14 | 9.1 gr | 80% | 23,627 psi | 63% | 1913 fps | 100% |
| Vihtavuori N133 | <<locked>> | 82% | 29,646 psi | 79% | 2766 fps | 95% |
| Vihtavuori N135 | <<locked>> | 88% | 29,617 psi | 79% | 2854 fps | 95.5% |
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 7 powders for 6 x 70 R loaded with the .243 | 62gr | Barnes Varmint Grenade FB. Vihtavuori N135 delivers the highest muzzle velocity at 2,972 fps; across all powders the maximum-charge window runs from 2,077 fps to 2,972 fps. Hodgdon TrailBoss gives the best case fill at 100 %, and 7 of the 7 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 62.0 gr projectile in 0.243" calls for a 1:9.0 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. Accurate 2495, ReloadSwiss RS 14, Hodgdon TrailBoss rank at the top here: for 6 x 70 R with the .243 | 62gr | Barnes Varmint Grenade FB 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.