Load Specifications
Load data in caliber .260 Ackley Improved with .264 | 130gr | Barnes TSX S bullet and 98 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Alliant Power Pro 2000-MR, Hodgdon Superformance and Alliant Reloder-17.
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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You can find more information in our FAQ: How can I use the Personalized Load Calculator?
Max Load - Barrel Length: 24"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2015 | <<locked>> | 84% | 54,926 psi | 88% | 2657 fps | 100% |
| Accurate 2495 | <<locked>> | 88% | 53,026 psi | 85% | 2677 fps | 100% |
| Accurate 2520 | <<locked>> | 84% | 55,303 psi | 89% | 2746 fps | 100% |
| Accurate 2700 | <<locked>> | 90% | 56,202 psi | 90% | 2733 fps | 97.6% |
| Accurate 3100ᴾ | <<locked>> | 100% | 40,234 psi | 65% | 2572 fps | 96.1% |
| Accurate 4064 | <<locked>> | 90% | 53,330 psi | 86% | 2726 fps | 100% |
| Accurate 4350 | <<locked>> | 98% | 52,953 psi | 85% | 2808 fps | 99.7% |
| ADI AR 2206H | <<locked>> | 86% | 54,201 psi | 87% | 2762 fps | 100% |
| ADI AR 2208 | <<locked>> | 92% | 55,114 psi | 88% | 2759 fps | 99.9% |
| ADI Benchmark 8208 | <<locked>> | 84% | 53,200 psi | 85% | 2713 fps | 100% |
| Alliant AR-Comp | <<locked>> | 84% | 54,027 psi | 87% | 2684 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 88% | 53,824 psi | 86% | 2877 fps | 99.9% |
| Alliant Reloder- TS 15.5 | <<locked>> | 92% | 54,897 psi | 88% | 2779 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 90% | 55,521 psi | 89% | 2802 fps | 100% |
| Alliant Reloder-16ᴾ | <<locked>> | 100% | 54,781 psi | 88% | 2867 fps | 99.9% |
| Alliant Reloder-17 | <<locked>> | 96% | 55,869 psi | 90% | 2904 fps | 100% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 38,899 psi | 62% | 2612 fps | 99% |
| Alliant Reloder-26ᴾ | <<locked>> | 100% | 43,279 psi | 69% | 2762 fps | 98.3% |
| Baschieri & Pellagri 107 | <<locked>> | 86% | 53,722 psi | 86% | 2772 fps | 99.7% |
| Bofors RP3 | <<locked>> | 92% | 55,390 psi | 89% | 2792 fps | 100% |
| Bofors RP7 | <<locked>> | 96% | 55,825 psi | 90% | 2769 fps | 97.8% |
| Hodgdon Benchmark | <<locked>> | 84% | 54,781 psi | 88% | 2694 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 86% | 55,825 psi | 90% | 2789 fps | 100% |
| Hodgdon CFE223 | <<locked>> | 82% | 54,491 psi | 87% | 2838 fps | 99.9% |
| Hodgdon H380 | <<locked>> | 90% | 53,069 psi | 85% | 2759 fps | 99.4% |
| Hodgdon H414 | <<locked>> | 98% | 56,420 psi | 90% | 2864 fps | 98.5% |
| Hodgdon H4350 | <<locked>> | 94% | 53,359 psi | 86% | 2769 fps | 96.8% |
| Hodgdon H4895 | <<locked>> | 86% | 54,737 psi | 88% | 2769 fps | 100% |
| Hodgdon Hybrid 100Vᴾ | <<locked>> | 100% | 50,865 psi | 82% | 2743 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 88% | 54,201 psi | 87% | 2805 fps | 100% |
| Hodgdon Superformance | <<locked>> | 96% | 53,388 psi | 86% | 2848 fps | 97.7% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 35,273 psi | 57% | 1673 fps | 100% |
| Hodgdon VARGET | <<locked>> | 88% | 55,869 psi | 90% | 2769 fps | 100% |
| IMR 3031 | <<locked>> | 86% | 54,708 psi | 88% | 2749 fps | 100% |
| IMR 4064 | <<locked>> | 90% | 54,795 psi | 88% | 2746 fps | 99.9% |
| IMR 4166 Enduron | <<locked>> | 88% | 54,549 psi | 87% | 2723 fps | 98.1% |
| IMR 4350ᴾ | <<locked>> | 100% | 56,144 psi | 90% | 2795 fps | 97.9% |
| IMR 4451 Enduron | <<locked>> | 94% | 54,404 psi | 87% | 2749 fps | 98% |
| IMR 4831ᴾ | <<locked>> | 100% | 53,635 psi | 86% | 2799 fps | 99.7% |
| IMR 4895 | <<locked>> | 88% | 53,374 psi | 86% | 2779 fps | 100% |
| IMR 8208 XBR | <<locked>> | 84% | 53,200 psi | 85% | 2713 fps | 100% |
| Lovex D073.6 | <<locked>> | 86% | 53,548 psi | 86% | 2733 fps | 100% |
| Lovex S060 | <<locked>> | 86% | 53,592 psi | 86% | 2687 fps | 100% |
| Lovex S062 | <<locked>> | 90% | 54,099 psi | 87% | 2736 fps | 100% |
| Lovex S065 | <<locked>> | 96% | 53,316 psi | 85% | 2740 fps | 98.9% |
| Lovex S070 | <<locked>> | 98% | 54,462 psi | 87% | 2776 fps | 98.3% |
| Norma 201 | <<locked>> | 88% | 56,043 psi | 90% | 2753 fps | 100% |
| Norma 202 | <<locked>> | 86% | 53,127 psi | 85% | 2703 fps | 100% |
| Norma 203B | <<locked>> | 90% | 54,694 psi | 88% | 2789 fps | 100% |
| Norma 204 | <<locked>> | 98% | 52,939 psi | 85% | 2785 fps | 96.1% |
| Norma URPᴾ | <<locked>> | 100% | 55,811 psi | 89% | 2848 fps | 99.8% |
| Ramshot Big Game | <<locked>> | 90% | 55,521 psi | 89% | 2818 fps | 100% |
| Ramshot Hunterᴾ | <<locked>> | 100% | 54,955 psi | 88% | 2851 fps | 99% |
| Ramshot TAC | <<locked>> | 84% | 53,359 psi | 86% | 2733 fps | 99.1% |
| Ramshot Wild Boar | <<locked>> | 84% | 52,852 psi | 85% | 2746 fps | 100% |
| Ramshot X-Terminator | <<locked>> | 82% | 53,766 psi | 86% | 2710 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 35,752 psi | 57% | 1716 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 82% | 55,956 psi | 90% | 2736 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 90% | 53,345 psi | 86% | 2740 fps | 98.4% |
| ReloadSwiss RS 52 | <<locked>> | 88% | 56,260 psi | 90% | 2867 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 94% | 55,753 psi | 89% | 2900 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 98% | 52,866 psi | 85% | 2831 fps | 99.6% |
| ReloadSwiss RS 70 | <<locked>> | 98% | 52,852 psi | 85% | 2861 fps | 99.4% |
| Rottweil R 901 | <<locked>> | 84% | 53,359 psi | 86% | 2680 fps | 100% |
| Rottweil R 902 | <<locked>> | 88% | 52,968 psi | 85% | 2700 fps | 100% |
| Rottweil R 903 | <<locked>> | 94% | 55,245 psi | 89% | 2785 fps | 100% |
| Rottweil R 907 | <<locked>> | 96% | 55,825 psi | 90% | 2769 fps | 97.8% |
| Shooters World Long Rifle | <<locked>> | 96% | 53,316 psi | 85% | 2740 fps | 98.9% |
| Shooters World Match Rifle | <<locked>> | 86% | 53,548 psi | 86% | 2733 fps | 100% |
| Shooters World Precision | <<locked>> | 90% | 54,099 psi | 87% | 2736 fps | 100% |
| Shooters World SW4350 | <<locked>> | 98% | 54,462 psi | 87% | 2776 fps | 98.3% |
| SNPE Vectan SP 11 | <<locked>> | 92% | 53,693 psi | 86% | 2799 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 86% | 55,187 psi | 88% | 2759 fps | 99.5% |
| SNPE Vectan SP 9 | <<locked>> | 88% | 55,985 psi | 90% | 2782 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 86% | 54,360 psi | 87% | 2644 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 92% | 54,592 psi | 88% | 2644 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 96% | 53,998 psi | 87% | 2700 fps | 98% |
| Somchem S321 | <<locked>> | 82% | 53,954 psi | 87% | 2736 fps | 100% |
| Somchem S335 | <<locked>> | 86% | 53,476 psi | 86% | 2641 fps | 100% |
| Somchem S341 | <<locked>> | 86% | 54,766 psi | 88% | 2749 fps | 100% |
| Somchem S355 | <<locked>> | 94% | 55,782 psi | 89% | 2785 fps | 100% |
| Somchem S365ᴾ | <<locked>> | 100% | 50,314 psi | 81% | 2802 fps | 100% |
| Somchem S385ᴾ | <<locked>> | 100% | 46,659 psi | 75% | 2680 fps | 96% |
| Vihtavuori N130 | <<locked>> | 82% | 53,954 psi | 87% | 2605 fps | 100% |
| Vihtavuori N133 | <<locked>> | 86% | 54,665 psi | 88% | 2631 fps | 100% |
| Vihtavuori N135 | <<locked>> | 88% | 52,837 psi | 85% | 2667 fps | 100% |
| Vihtavuori N140 | <<locked>> | 88% | 53,780 psi | 86% | 2687 fps | 100% |
| Vihtavuori N150 | <<locked>> | 94% | 53,635 psi | 86% | 2713 fps | 100% |
| Vihtavuori N160 | <<locked>> | 98% | 54,824 psi | 88% | 2792 fps | 99.7% |
| Vihtavuori N530 | <<locked>> | 84% | 53,563 psi | 86% | 2710 fps | 100% |
| Vihtavuori N540 | <<locked>> | 90% | 55,492 psi | 89% | 2730 fps | 100% |
| Vihtavuori N550 | <<locked>> | 98% | 53,954 psi | 87% | 2802 fps | 99.6% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 42,612 psi | 68% | 2680 fps | 98.9% |
| Winchester 6.5 StaBALL | <<locked>> | 98% | 55,274 psi | 89% | 2776 fps | 100% |
| Winchester 748 | <<locked>> | 84% | 53,403 psi | 86% | 2756 fps | 100% |
| Winchester 760 | <<locked>> | 98% | 56,420 psi | 90% | 2864 fps | 98.5% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 34,664 psi | 56% | 2608 fps | 98.9% |
| Winchester StaBALL Match | <<locked>> | 88% | 55,738 psi | 89% | 2789 fps | 100% |
Recommended = one of the top powders for this cartridge and bullet combination.
Start Load - Barrel Length: 24"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2015 | <<locked>> | 80% | 48,385 psi | 78% | 2569 fps | 100% |
| Accurate 2495 | <<locked>> | 80% | 40,741 psi | 65% | 2493 fps | 100% |
| Accurate 2520 | <<locked>> | 80% | 47,979 psi | 77% | 2641 fps | 100% |
| Accurate 2700 | <<locked>> | 84% | 46,267 psi | 74% | 2575 fps | 95.6% |
| Accurate 3100 | <<locked>> | 98% | 37,434 psi | 60% | 2516 fps | 95.2% |
| Accurate 4064 | <<locked>> | 80% | 38,566 psi | 62% | 2490 fps | 100% |
| Accurate 4350 | <<locked>> | 84% | 32,372 psi | 52% | 2418 fps | 95.4% |
| ADI AR 2206H | <<locked>> | 80% | 44,556 psi | 71% | 2605 fps | 99.4% |
| ADI AR 2208 | <<locked>> | 80% | 37,971 psi | 61% | 2461 fps | 97.7% |
| ADI Benchmark 8208 | <<locked>> | 80% | 46,688 psi | 75% | 2612 fps | 100% |
| Alliant AR-Comp | <<locked>> | 80% | 47,253 psi | 76% | 2595 fps | 100% |
| Alliant Power Pro 2000-MR | 37.5 gr | 80% | 40,567 psi | 65% | 2635 fps | 98.3% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 37,333 psi | 60% | 2477 fps | 98.9% |
| Alliant Reloder-15 | <<locked>> | 80% | 40,219 psi | 64% | 2539 fps | 98.4% |
| Alliant Reloder-16 | <<locked>> | 84% | 32,967 psi | 53% | 2438 fps | 95.5% |
| Alliant Reloder-17 | 36.9 gr | 80% | 32,155 psi | 52% | 2444 fps | 97.1% |
| Alliant Reloder-23 | <<locked>> | 90% | 28,384 psi | 46% | 2339 fps | 95.1% |
| Alliant Reloder-26 | <<locked>> | 94% | 34,998 psi | 56% | 2572 fps | 95.5% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 43,903 psi | 70% | 2612 fps | 98.6% |
| Bofors RP3 | <<locked>> | 80% | 36,956 psi | 59% | 2480 fps | 98.9% |
| Bofors RP7 | <<locked>> | 88% | 43,207 psi | 69% | 2559 fps | 95.1% |
| Hodgdon Benchmark | <<locked>> | 80% | 48,544 psi | 78% | 2602 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 80% | 45,469 psi | 73% | 2631 fps | 100% |
| Hodgdon CFE223 | <<locked>> | 80% | 50,604 psi | 81% | 2779 fps | 99.8% |
| Hodgdon H380 | <<locked>> | 80% | 37,927 psi | 61% | 2487 fps | 96.6% |
| Hodgdon H414 | <<locked>> | 90% | 43,163 psi | 69% | 2644 fps | 95.9% |
| Hodgdon H4350 | <<locked>> | 90% | 47,166 psi | 76% | 2667 fps | 95.3% |
| Hodgdon H4895 | <<locked>> | 80% | 44,947 psi | 72% | 2615 fps | 99.7% |
| Hodgdon Hybrid 100V | <<locked>> | 82% | 28,181 psi | 45% | 2283 fps | 95.4% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 41,118 psi | 66% | 2589 fps | 99.5% |
| Hodgdon Superformance | 43.9 gr | 90% | 42,714 psi | 68% | 2654 fps | 95% |
| Hodgdon TrailBoss | <<locked>> | 80% | 26,382 psi | 42% | 1499 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 43,250 psi | 69% | 2569 fps | 99.5% |
| IMR 3031 | <<locked>> | 80% | 44,672 psi | 72% | 2605 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 39,856 psi | 64% | 2493 fps | 98.4% |
| IMR 4166 Enduron | <<locked>> | 80% | 42,438 psi | 68% | 2516 fps | 95.5% |
| IMR 4350 | <<locked>> | 92% | 43,584 psi | 70% | 2589 fps | 95.2% |
| IMR 4451 Enduron | <<locked>> | 86% | 42,366 psi | 68% | 2543 fps | 95.3% |
| IMR 4831 | <<locked>> | 84% | 31,415 psi | 50% | 2379 fps | 95% |
| IMR 4895 | <<locked>> | 80% | 41,191 psi | 66% | 2569 fps | 99% |
| IMR 8208 XBR | <<locked>> | 80% | 46,688 psi | 75% | 2612 fps | 100% |
| Lovex D073.6 | <<locked>> | 80% | 43,656 psi | 70% | 2582 fps | 100% |
| Lovex S060 | <<locked>> | 80% | 44,788 psi | 72% | 2546 fps | 99.4% |
| Lovex S062 | <<locked>> | 80% | 39,711 psi | 64% | 2497 fps | 99.5% |
| Lovex S065 | <<locked>> | 84% | 36,869 psi | 59% | 2438 fps | 95.3% |
| Lovex S070 | <<locked>> | 90% | 42,235 psi | 68% | 2569 fps | 95.8% |
| Norma 201 | <<locked>> | 80% | 43,685 psi | 70% | 2559 fps | 99.8% |
| Norma 202 | <<locked>> | 80% | 43,830 psi | 70% | 2562 fps | 100% |
| Norma 203B | <<locked>> | 80% | 39,581 psi | 63% | 2530 fps | 98.7% |
| Norma 204 | <<locked>> | 96% | 49,487 psi | 79% | 2730 fps | 95.3% |
| Norma URP | <<locked>> | 84% | 32,982 psi | 53% | 2425 fps | 95.4% |
| Ramshot Big Game | <<locked>> | 80% | 39,218 psi | 63% | 2543 fps | 98.5% |
| Ramshot Hunter | <<locked>> | 90% | 39,233 psi | 63% | 2572 fps | 95.6% |
| Ramshot TAC | <<locked>> | 80% | 46,746 psi | 75% | 2621 fps | 98.1% |
| Ramshot Wild Boar | <<locked>> | 80% | 46,093 psi | 74% | 2638 fps | 99.5% |
| Ramshot X-Terminator | <<locked>> | 80% | 50,473 psi | 81% | 2661 fps | 99.8% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 26,614 psi | 43% | 1532 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 80% | 52,402 psi | 84% | 2687 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 82% | 40,872 psi | 66% | 2523 fps | 95.8% |
| ReloadSwiss RS 52 | <<locked>> | 80% | 42,641 psi | 68% | 2644 fps | 98.8% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 34,316 psi | 55% | 2513 fps | 99.6% |
| ReloadSwiss RS 62 | <<locked>> | 86% | 34,679 psi | 56% | 2493 fps | 95.8% |
| ReloadSwiss RS 70 | <<locked>> | 88% | 37,376 psi | 60% | 2562 fps | 95.9% |
| Rottweil R 901 | <<locked>> | 80% | 47,514 psi | 76% | 2595 fps | 100% |
| Rottweil R 902 | <<locked>> | 80% | 41,539 psi | 67% | 2513 fps | 99.7% |
| Rottweil R 903 | <<locked>> | 80% | 34,635 psi | 56% | 2425 fps | 98.1% |
| Rottweil R 907 | <<locked>> | 88% | 43,207 psi | 69% | 2559 fps | 95.1% |
| Shooters World Long Rifle | <<locked>> | 84% | 36,869 psi | 59% | 2438 fps | 95.3% |
| Shooters World Match Rifle | <<locked>> | 80% | 43,656 psi | 70% | 2582 fps | 100% |
| Shooters World Precision | <<locked>> | 80% | 39,711 psi | 64% | 2497 fps | 99.5% |
| Shooters World SW4350 | <<locked>> | 90% | 42,235 psi | 68% | 2569 fps | 95.8% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 35,969 psi | 58% | 2480 fps | 97.8% |
| SNPE Vectan SP 7 | <<locked>> | 80% | 44,918 psi | 72% | 2595 fps | 98.2% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 43,236 psi | 69% | 2579 fps | 99.2% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 45,020 psi | 72% | 2510 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 37,420 psi | 60% | 2382 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 88% | 41,191 psi | 66% | 2487 fps | 95.2% |
| Somchem S321 | <<locked>> | 80% | 50,575 psi | 81% | 2687 fps | 100% |
| Somchem S335 | <<locked>> | 80% | 44,730 psi | 72% | 2513 fps | 100% |
| Somchem S341 | <<locked>> | 80% | 44,701 psi | 72% | 2592 fps | 99.4% |
| Somchem S355 | <<locked>> | 80% | 35,766 psi | 57% | 2438 fps | 98.2% |
| Somchem S365 | <<locked>> | 80% | 25,643 psi | 41% | 2264 fps | 95.6% |
| Somchem S385 | <<locked>> | 98% | 43,584 psi | 70% | 2625 fps | 95.2% |
| Vihtavuori N130 | <<locked>> | 80% | 50,894 psi | 82% | 2566 fps | 100% |
| Vihtavuori N133 | <<locked>> | 80% | 45,426 psi | 73% | 2503 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 40,988 psi | 66% | 2490 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 41,524 psi | 67% | 2500 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 33,794 psi | 54% | 2372 fps | 98.8% |
| Vihtavuori N160 | <<locked>> | 82% | 32,198 psi | 52% | 2375 fps | 95% |
| Vihtavuori N530 | <<locked>> | 80% | 46,862 psi | 75% | 2608 fps | 100% |
| Vihtavuori N540 | <<locked>> | 80% | 40,103 psi | 64% | 2490 fps | 100% |
| Vihtavuori N550 | <<locked>> | 84% | 33,895 psi | 54% | 2431 fps | 95.4% |
| Vihtavuori N555 | <<locked>> | 90% | 30,226 psi | 48% | 2408 fps | 95.2% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 30,037 psi | 48% | 2300 fps | 96.4% |
| Winchester 748 | <<locked>> | 80% | 46,731 psi | 75% | 2654 fps | 100% |
| Winchester 760 | <<locked>> | 88% | 40,350 psi | 65% | 2589 fps | 95% |
| Winchester StaBALL HD | <<locked>> | 94% | 28,311 psi | 45% | 2411 fps | 95.5% |
| Winchester StaBALL Match | <<locked>> | 80% | 42,496 psi | 68% | 2575 fps | 99.5% |
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 98 powders for .260 Ackley Improved loaded with the .264 | 130gr | Barnes TSX S. Alliant Reloder-17 delivers the highest muzzle velocity at 2,904 fps; across all powders the maximum-charge window runs from 1,673 fps to 2,904 fps. Accurate 3100 gives the best case fill at 100 %, and 98 of the 98 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (430 MPa), the top charges use 56–90 %, leaving at least 10 % headroom. The 130.0 gr projectile in 0.264" calls for a 1:9.0 twist; slower twists will usually not stabilise this weight. Accurate 3100, Alliant Reloder-16, 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. Alliant Power Pro 2000-MR, Hodgdon Superformance, Alliant Reloder-17 rank at the top here: for .260 Ackley Improved with the .264 | 130gr | Barnes TSX S 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.