Load Specifications
Load data in caliber 6.5 x 51 R Jap. Arisaka with .258 | 120gr | Rim Rock RNFP Gas Check bullet and 51 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: 31"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2495 | <<locked>> | 84% | 36,013 psi | 84% | 2631 fps | 100% |
| Accurate 4064 | <<locked>> | 86% | 36,811 psi | 86% | 2684 fps | 100% |
| Accurate 4350 | <<locked>> | 94% | 37,086 psi | 87% | 2756 fps | 98.1% |
| ADI AR 2208 | <<locked>> | 84% | 36,912 psi | 86% | 2648 fps | 98.3% |
| Alliant Power Pro 2000-MR | <<locked>> | 82% | 36,912 psi | 86% | 2779 fps | 98.3% |
| Alliant Reloder- TS 15.5 | <<locked>> | 86% | 38,000 psi | 89% | 2707 fps | 99.6% |
| Alliant Reloder-15 | <<locked>> | 84% | 38,624 psi | 90% | 2726 fps | 98.8% |
| Alliant Reloder-16 | <<locked>> | 94% | 38,319 psi | 90% | 2785 fps | 98.5% |
| Alliant Reloder-17 | <<locked>> | 90% | 38,101 psi | 89% | 2815 fps | 99.6% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 31,618 psi | 74% | 2657 fps | 98.1% |
| Alliant Reloder-26ᴾ | <<locked>> | 100% | 35,331 psi | 83% | 2815 fps | 97.2% |
| Bofors RP3 | <<locked>> | 86% | 36,912 psi | 86% | 2703 fps | 99.5% |
| Hodgdon H380 | <<locked>> | 86% | 38,682 psi | 90% | 2723 fps | 97.8% |
| Hodgdon Hybrid 100V | <<locked>> | 96% | 37,173 psi | 87% | 2717 fps | 99.3% |
| Hodgdon LEVERevolution | <<locked>> | 82% | 36,898 psi | 86% | 2723 fps | 99.5% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 33,881 psi | 79% | 1759 fps | 100% |
| IMR 4064 | <<locked>> | 84% | 38,711 psi | 90% | 2677 fps | 98.8% |
| IMR 4831 | <<locked>> | 96% | 38,711 psi | 90% | 2766 fps | 98.5% |
| IMR 4895 | <<locked>> | 82% | 36,970 psi | 86% | 2703 fps | 98.9% |
| Lovex D073.6 | <<locked>> | 82% | 38,421 psi | 90% | 2703 fps | 100% |
| Lovex S062 | <<locked>> | 84% | 37,420 psi | 87% | 2664 fps | 99.6% |
| Lovex S065 | <<locked>> | 90% | 37,173 psi | 87% | 2661 fps | 96.6% |
| Norma 201 | <<locked>> | 82% | 38,638 psi | 90% | 2680 fps | 99.7% |
| Norma 203B | <<locked>> | 84% | 37,884 psi | 89% | 2713 fps | 99.1% |
| Norma URP | <<locked>> | 94% | 38,058 psi | 89% | 2766 fps | 98.2% |
| Ramshot Big Game | <<locked>> | 84% | 37,985 psi | 89% | 2736 fps | 99% |
| Ramshot Hunter | <<locked>> | 94% | 37,521 psi | 88% | 2753 fps | 96.3% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 33,953 psi | 79% | 1801 fps | 100% |
| ReloadSwiss RS 52 | <<locked>> | 82% | 37,942 psi | 89% | 2779 fps | 98.7% |
| ReloadSwiss RS 60 | <<locked>> | 88% | 37,971 psi | 89% | 2818 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 94% | 37,405 psi | 87% | 2782 fps | 97.9% |
| ReloadSwiss RS 70 | <<locked>> | 94% | 38,638 psi | 90% | 2812 fps | 97.6% |
| Rottweil R 902 | <<locked>> | 82% | 36,448 psi | 85% | 2625 fps | 99.5% |
| Rottweil R 903 | <<locked>> | 88% | 37,173 psi | 87% | 2700 fps | 99.4% |
| Shooters World Long Rifle | <<locked>> | 90% | 37,173 psi | 87% | 2661 fps | 96.6% |
| Shooters World Match Rifle | <<locked>> | 82% | 38,421 psi | 90% | 2703 fps | 100% |
| Shooters World Precision | <<locked>> | 84% | 37,420 psi | 87% | 2664 fps | 99.6% |
| SNPE Vectan SP 11 | <<locked>> | 86% | 36,869 psi | 86% | 2720 fps | 98.8% |
| SNPE Vectan Tubal 5000 | <<locked>> | 84% | 36,216 psi | 85% | 2556 fps | 100% |
| Somchem S355 | <<locked>> | 88% | 38,508 psi | 90% | 2713 fps | 99.4% |
| Somchem S365 | <<locked>> | 98% | 38,667 psi | 90% | 2822 fps | 100% |
| Vihtavuori N135 | <<locked>> | 82% | 36,216 psi | 85% | 2612 fps | 100% |
| Vihtavuori N140 | <<locked>> | 82% | 37,594 psi | 88% | 2631 fps | 100% |
| Vihtavuori N150 | <<locked>> | 88% | 36,985 psi | 86% | 2651 fps | 99.8% |
| Vihtavuori N160 | <<locked>> | 92% | 37,507 psi | 88% | 2710 fps | 97.9% |
| Vihtavuori N540 | <<locked>> | 84% | 38,392 psi | 90% | 2671 fps | 100% |
| Vihtavuori N550 | <<locked>> | 92% | 36,695 psi | 86% | 2717 fps | 97.6% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 33,591 psi | 79% | 2726 fps | 97.9% |
| Winchester 6.5 StaBALL | <<locked>> | 92% | 38,174 psi | 89% | 2697 fps | 99.5% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 27,702 psi | 65% | 2625 fps | 97.2% |
| Winchester StaBALL Match | <<locked>> | 82% | 38,435 psi | 90% | 2713 fps | 99.4% |
Start Load - Barrel Length: 31"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2495 | <<locked>> | 80% | 30,850 psi | 72% | 2526 fps | 100% |
| Accurate 4064 | <<locked>> | 80% | 29,443 psi | 69% | 2520 fps | 99.8% |
| Accurate 4350 | <<locked>> | 88% | 29,153 psi | 68% | 2569 fps | 95.6% |
| ADI AR 2208 | <<locked>> | 80% | 31,908 psi | 75% | 2530 fps | 96.8% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 34,185 psi | 80% | 2710 fps | 97.5% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 30,763 psi | 72% | 2546 fps | 98.2% |
| Alliant Reloder-15 | <<locked>> | 80% | 33,315 psi | 78% | 2608 fps | 97.6% |
| Alliant Reloder-16 | <<locked>> | 86% | 29,254 psi | 68% | 2552 fps | 95.2% |
| Alliant Reloder-17 | <<locked>> | 80% | 26,368 psi | 62% | 2497 fps | 95.8% |
| Alliant Reloder-23 | <<locked>> | 94% | 25,788 psi | 60% | 2484 fps | 95.3% |
| Alliant Reloder-26 | <<locked>> | 98% | 32,648 psi | 76% | 2743 fps | 96.1% |
| Bofors RP3 | <<locked>> | 80% | 29,327 psi | 69% | 2526 fps | 97.9% |
| Hodgdon H380 | <<locked>> | 80% | 30,734 psi | 72% | 2536 fps | 95.3% |
| Hodgdon Hybrid 100V | <<locked>> | 86% | 26,121 psi | 61% | 2438 fps | 95.8% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 34,127 psi | 80% | 2664 fps | 99.1% |
| Hodgdon TrailBoss | <<locked>> | 80% | 24,772 psi | 58% | 1568 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 33,402 psi | 78% | 2562 fps | 97.6% |
| IMR 4831 | <<locked>> | 88% | 28,776 psi | 67% | 2533 fps | 95.4% |
| IMR 4895 | <<locked>> | 80% | 34,156 psi | 80% | 2641 fps | 98.3% |
| Lovex D073.6 | <<locked>> | 80% | 35,418 psi | 83% | 2644 fps | 100% |
| Lovex S062 | <<locked>> | 80% | 32,503 psi | 76% | 2556 fps | 98.9% |
| Lovex S065 | <<locked>> | 88% | 34,737 psi | 81% | 2605 fps | 95.8% |
| Norma 201 | <<locked>> | 80% | 36,027 psi | 84% | 2625 fps | 99.5% |
| Norma 203B | <<locked>> | 80% | 32,648 psi | 76% | 2595 fps | 97.9% |
| Norma URP | <<locked>> | 88% | 30,821 psi | 72% | 2595 fps | 95.9% |
| Ramshot Big Game | <<locked>> | 80% | 32,576 psi | 76% | 2612 fps | 97.7% |
| Ramshot Hunter | <<locked>> | 92% | 35,099 psi | 82% | 2697 fps | 95.4% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 24,584 psi | 57% | 1604 fps | 100% |
| ReloadSwiss RS 52 | <<locked>> | 80% | 34,969 psi | 82% | 2713 fps | 98.1% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 28,384 psi | 66% | 2572 fps | 99% |
| ReloadSwiss RS 62 | <<locked>> | 88% | 29,747 psi | 70% | 2595 fps | 95.2% |
| ReloadSwiss RS 70 | <<locked>> | 90% | 33,228 psi | 78% | 2677 fps | 95.6% |
| Rottweil R 902 | <<locked>> | 80% | 33,953 psi | 79% | 2572 fps | 99.1% |
| Rottweil R 903 | <<locked>> | 80% | 27,412 psi | 64% | 2467 fps | 96.9% |
| Shooters World Long Rifle | <<locked>> | 88% | 34,737 psi | 81% | 2605 fps | 95.8% |
| Shooters World Match Rifle | <<locked>> | 80% | 35,418 psi | 83% | 2644 fps | 100% |
| Shooters World Precision | <<locked>> | 80% | 32,503 psi | 76% | 2556 fps | 98.9% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 29,486 psi | 69% | 2539 fps | 96.7% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 31,386 psi | 73% | 2457 fps | 100% |
| Somchem S355 | <<locked>> | 80% | 28,747 psi | 67% | 2487 fps | 97.1% |
| Somchem S365 | <<locked>> | 84% | 23,134 psi | 54% | 2405 fps | 95.8% |
| Vihtavuori N135 | <<locked>> | 80% | 33,620 psi | 79% | 2562 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 35,056 psi | 82% | 2582 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 27,470 psi | 64% | 2428 fps | 98% |
| Vihtavuori N160 | <<locked>> | 86% | 30,139 psi | 70% | 2536 fps | 95.5% |
| Vihtavuori N540 | <<locked>> | 80% | 33,199 psi | 78% | 2562 fps | 99.9% |
| Vihtavuori N550 | <<locked>> | 88% | 31,662 psi | 74% | 2598 fps | 96% |
| Vihtavuori N555 | <<locked>> | 94% | 27,006 psi | 63% | 2552 fps | 95.3% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 24,685 psi | 58% | 2349 fps | 95% |
| Winchester StaBALL HD | <<locked>> | 98% | 25,875 psi | 60% | 2556 fps | 95.9% |
| Winchester StaBALL Match | <<locked>> | 80% | 35,563 psi | 83% | 2654 fps | 99% |
ᴾ possible press load - work up slowly to this load while watching for signs of excessive pressure.
This overview compares 77 powders for 6.5 x 51 R Jap. Arisaka loaded with the .258 | 120gr | Rim Rock RNFP Gas Check. Somchem S365 delivers the highest muzzle velocity at 2,822 fps; across all powders the maximum-charge window runs from 1,759 fps to 2,822 fps. Accurate 3100 gives the best case fill at 100 %, and 77 of the 77 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (295 MPa), the top charges use 65–90 %, leaving at least 10 % headroom. The 120.0 gr projectile in 0.258" calls for a 1:12.5 twist; slower twists will usually not stabilise this weight. Accurate 3100, Alliant Reloder-22, Alliant Reloder-23 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 2700, Accurate 3100, ADI AR 2209 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.