Load Specifications
Bullet Manufacturer:Sierra
Bullet Weight:165 gr
Bullet Diameter:0.284"
Bullet Length:<<locked>>
Caliber:.280 Ackley Improved load data
Case Length (l3):2.54"
Cartridge Length (C.O.L.):<<locked>>
Case Capacity:74 Grains of Water
Primer Size:Large Rifle (LR)
Barrel Length:24"
Max. allowed Pressure:65,000 psi
Recommended Twist Rate:1:9.5
Load data in caliber .280 Ackley Improved with .284 | 165gr | Sierra Tipped GameKing bullet and 103 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Alliant Reloder-26, ReloadSwiss RS 70 and Hodgdon Superformance.
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.
A valid access license is required to use the Personalized Load Calculator.
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 2495 | <<locked>> | 84% | 58,421 psi | 90% | 2644 fps | 100% |
| Accurate 2700 | <<locked>> | 88% | 57,421 psi | 88% | 2684 fps | 99.2% |
| Accurate 3100ᴾ | <<locked>> | 100% | 54,375 psi | 84% | 2718 fps | 99.7% |
| Accurate 4064 | <<locked>> | 86% | 58,624 psi | 90% | 2697 fps | 100% |
| Accurate 4350 | <<locked>> | 92% | 55,956 psi | 86% | 2762 fps | 100% |
| ADI AR 2206H | <<locked>> | 82% | 57,522 psi | 89% | 2728 fps | 100% |
| ADI AR 2208 | <<locked>> | 88% | 58,798 psi | 90% | 2735 fps | 100% |
| ADI AR 2209 | <<locked>> | 98% | 56,739 psi | 87% | 2805 fps | 98.7% |
| ADI AR 2213ᴾ | <<locked>> | 100% | 54,592 psi | 84% | 2801 fps | 97.3% |
| Alliant Power Pro 2000-MR | <<locked>> | 84% | 58,363 psi | 90% | 2858 fps | 100% |
| Alliant Reloder- TS 15.5 | <<locked>> | 86% | 56,028 psi | 86% | 2708 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 84% | 56,405 psi | 87% | 2731 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 94% | 56,536 psi | 87% | 2813 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 90% | 57,885 psi | 89% | 2836 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 98% | 55,927 psi | 86% | 2793 fps | 98.7% |
| Alliant Reloder-22ᴾ | <<locked>> | 100% | 54,041 psi | 83% | 2798 fps | 98.5% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 50,401 psi | 78% | 2731 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 44,005 psi | 68% | 2666 fps | 99.4% |
| Alliant Reloder-26ᴾ | <<locked>> | 100% | 58,798 psi | 90% | 2924 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 82% | 57,624 psi | 89% | 2750 fps | 100% |
| Bofors RP15ᴾ | <<locked>> | 100% | 48,660 psi | 75% | 2720 fps | 97.5% |
| Bofors RP3 | <<locked>> | 86% | 57,101 psi | 88% | 2726 fps | 100% |
| Bofors RP5ᴾ | <<locked>> | 100% | 53,200 psi | 82% | 2799 fps | 98.5% |
| Bofors RP7 | <<locked>> | 90% | 56,376 psi | 87% | 2715 fps | 99.3% |
| Hodgdon H380 | <<locked>> | 86% | 57,377 psi | 88% | 2744 fps | 100% |
| Hodgdon H414 | <<locked>> | 88% | 55,724 psi | 86% | 2780 fps | 99.6% |
| Hodgdon H4350 | <<locked>> | 92% | 56,014 psi | 86% | 2746 fps | 98.9% |
| Hodgdon H4831 SCᴾ | <<locked>> | 100% | 57,406 psi | 88% | 2785 fps | 97.2% |
| Hodgdon H4895 | <<locked>> | 82% | 58,218 psi | 90% | 2735 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 96% | 57,000 psi | 88% | 2740 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 84% | 55,187 psi | 85% | 2726 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 42,873 psi | 66% | 2694 fps | 96.8% |
| Hodgdon Superformance | <<locked>> | 92% | 58,450 psi | 90% | 2854 fps | 99.7% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,347 psi | 57% | 1667 fps | 100% |
| Hodgdon VARGET | <<locked>> | 86% | 58,305 psi | 90% | 2723 fps | 100% |
| IMR 3031 | <<locked>> | 84% | 57,725 psi | 89% | 2691 fps | 100% |
| IMR 4064 | <<locked>> | 88% | 57,725 psi | 89% | 2710 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 88% | 56,347 psi | 87% | 2691 fps | 99.5% |
| IMR 4350 | <<locked>> | 94% | 57,101 psi | 88% | 2746 fps | 99.4% |
| IMR 4451 Enduron | <<locked>> | 90% | 57,914 psi | 89% | 2740 fps | 99.6% |
| IMR 4831 | <<locked>> | 98% | 56,942 psi | 88% | 2763 fps | 100% |
| IMR 4895 | <<locked>> | 84% | 57,899 psi | 89% | 2757 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 98% | 56,173 psi | 86% | 2736 fps | 97.2% |
| IMR 7828 SSCᴾ | <<locked>> | 100% | 56,666 psi | 87% | 2836 fps | 97.7% |
| Lovex D073.6 | <<locked>> | 82% | 58,349 psi | 90% | 2703 fps | 100% |
| Lovex S060 | <<locked>> | 82% | 56,188 psi | 86% | 2652 fps | 100% |
| Lovex S062 | <<locked>> | 86% | 58,523 psi | 90% | 2709 fps | 100% |
| Lovex S065 | <<locked>> | 92% | 57,899 psi | 89% | 2733 fps | 100% |
| Lovex S070 | <<locked>> | 92% | 55,811 psi | 86% | 2727 fps | 99.6% |
| Lovex S071ᴾ | <<locked>> | 100% | 45,078 psi | 69% | 2573 fps | 98.7% |
| Norma 201 | <<locked>> | 82% | 56,333 psi | 87% | 2671 fps | 100% |
| Norma 202 | <<locked>> | 82% | 57,203 psi | 88% | 2668 fps | 100% |
| Norma 203B | <<locked>> | 84% | 55,695 psi | 86% | 2717 fps | 100% |
| Norma 204 | <<locked>> | 94% | 58,175 psi | 90% | 2802 fps | 98.8% |
| Norma MRPᴾ | <<locked>> | 100% | 56,797 psi | 87% | 2880 fps | 99.7% |
| Norma URP | <<locked>> | 94% | 58,030 psi | 89% | 2794 fps | 100% |
| Ramshot Big Game | <<locked>> | 84% | 56,289 psi | 87% | 2742 fps | 100% |
| Ramshot Grand | <<locked>> | 98% | 56,985 psi | 88% | 2845 fps | 98% |
| Ramshot Hunter | <<locked>> | 94% | 56,913 psi | 88% | 2803 fps | 99.9% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 52,953 psi | 81% | 2764 fps | 98.8% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,029 psi | 59% | 1704 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 86% | 57,217 psi | 88% | 2729 fps | 99.8% |
| ReloadSwiss RS 52 | <<locked>> | 82% | 57,624 psi | 89% | 2799 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 88% | 57,377 psi | 88% | 2827 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 92% | 55,637 psi | 86% | 2785 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 94% | 57,856 psi | 89% | 2865 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 43,482 psi | 67% | 2681 fps | 97.7% |
| Rottweil R 902 | <<locked>> | 84% | 56,884 psi | 88% | 2670 fps | 100% |
| Rottweil R 903 | <<locked>> | 88% | 56,942 psi | 88% | 2719 fps | 100% |
| Rottweil R 904 | <<locked>> | 98% | 58,450 psi | 90% | 2775 fps | 98% |
| Rottweil R 905 | <<locked>> | 98% | 55,579 psi | 86% | 2782 fps | 98.7% |
| Rottweil R 907 | <<locked>> | 90% | 56,376 psi | 87% | 2715 fps | 99.3% |
| Shooters World Long Rifle | <<locked>> | 92% | 57,899 psi | 89% | 2733 fps | 100% |
| Shooters World Match Rifle | <<locked>> | 82% | 58,349 psi | 90% | 2703 fps | 100% |
| Shooters World Precision | <<locked>> | 86% | 58,523 psi | 90% | 2709 fps | 100% |
| Shooters World SW4350 | <<locked>> | 92% | 55,811 psi | 86% | 2726 fps | 99.6% |
| SNPE Vectan SP 11 | <<locked>> | 88% | 58,552 psi | 90% | 2778 fps | 100% |
| SNPE Vectan SP 9 | <<locked>> | 82% | 56,130 psi | 86% | 2704 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 82% | 57,246 psi | 88% | 2603 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 88% | 57,943 psi | 89% | 2603 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 92% | 57,856 psi | 89% | 2693 fps | 99.6% |
| SNPE Vectan Tubal 8000ᴾ | <<locked>> | 100% | 58,378 psi | 90% | 2828 fps | 99.1% |
| Somchem S335 | <<locked>> | 82% | 56,768 psi | 87% | 2600 fps | 100% |
| Somchem S341 | <<locked>> | 82% | 58,610 psi | 90% | 2721 fps | 100% |
| Somchem S355 | <<locked>> | 88% | 57,014 psi | 88% | 2717 fps | 100% |
| Somchem S361 | <<locked>> | 96% | 56,739 psi | 87% | 2720 fps | 97% |
| Somchem S365 | <<locked>> | 96% | 57,580 psi | 89% | 2798 fps | 100% |
| Somchem S385 | <<locked>> | 98% | 55,840 psi | 86% | 2755 fps | 99.2% |
| Unknown powder | <<locked>> | 90% | 55,129 psi | 85% | 2751 fps | 100% |
| Vihtavuori N133 | <<locked>> | 84% | 57,261 psi | 88% | 2581 fps | 100% |
| Vihtavuori N135 | <<locked>> | 84% | 57,261 psi | 88% | 2628 fps | 100% |
| Vihtavuori N140 | <<locked>> | 84% | 56,724 psi | 87% | 2638 fps | 100% |
| Vihtavuori N150 | <<locked>> | 94% | 58,581 psi | 90% | 2696 fps | 100% |
| Vihtavuori N160 | <<locked>> | 90% | 55,622 psi | 86% | 2723 fps | 100% |
| Vihtavuori N165ᴾ | <<locked>> | 100% | 51,039 psi | 79% | 2650 fps | 98.1% |
| Vihtavuori N540 | <<locked>> | 84% | 56,521 psi | 87% | 2666 fps | 100% |
| Vihtavuori N550 | <<locked>> | 90% | 55,883 psi | 86% | 2766 fps | 100% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 56,985 psi | 88% | 2803 fps | 100% |
| Vihtavuori N560ᴾ | <<locked>> | 100% | 53,780 psi | 83% | 2818 fps | 96.9% |
| Winchester 6.5 StaBALL | <<locked>> | 92% | 56,318 psi | 87% | 2710 fps | 100% |
| Winchester 760 | <<locked>> | 88% | 55,724 psi | 86% | 2780 fps | 99.6% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 45,295 psi | 70% | 2788 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 96% | 54,172 psi | 83% | 2725 fps | 98.3% |
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 2495 | <<locked>> | 80% | 51,605 psi | 79% | 2559 fps | 100% |
| Accurate 2700 | <<locked>> | 80% | 44,295 psi | 68% | 2477 fps | 97.2% |
| Accurate 3100 | <<locked>> | 86% | 33,330 psi | 51% | 2350 fps | 95.8% |
| Accurate 4064 | <<locked>> | 80% | 48,878 psi | 75% | 2566 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 37,217 psi | 57% | 2448 fps | 98.6% |
| ADI AR 2206H | <<locked>> | 80% | 54,230 psi | 83% | 2681 fps | 100% |
| ADI AR 2208 | <<locked>> | 80% | 45,948 psi | 71% | 2541 fps | 99.9% |
| ADI AR 2209 | <<locked>> | 88% | 41,060 psi | 63% | 2533 fps | 95.3% |
| ADI AR 2213 | <<locked>> | 96% | 47,688 psi | 73% | 2686 fps | 95.7% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 50,850 psi | 78% | 2750 fps | 100% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 46,456 psi | 71% | 2565 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 49,719 psi | 77% | 2631 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 80% | 36,289 psi | 56% | 2455 fps | 98.7% |
| Alliant Reloder-17 | <<locked>> | 80% | 40,930 psi | 63% | 2571 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 88% | 40,770 psi | 63% | 2528 fps | 95.4% |
| Alliant Reloder-22 | <<locked>> | 92% | 40,727 psi | 63% | 2572 fps | 95.5% |
| Alliant Reloder-23 | <<locked>> | 80% | 26,614 psi | 41% | 2226 fps | 96.6% |
| Alliant Reloder-25 | <<locked>> | 90% | 31,908 psi | 49% | 2387 fps | 95.6% |
| Alliant Reloder-26 | 50.7 gr | 82% | 30,327 psi | 47% | 2388 fps | 95.9% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 53,998 psi | 83% | 2699 fps | 100% |
| Bofors RP15 | <<locked>> | 94% | 40,176 psi | 62% | 2559 fps | 95.2% |
| Bofors RP3 | <<locked>> | 80% | 46,891 psi | 72% | 2579 fps | 100% |
| Bofors RP5 | <<locked>> | 92% | 40,727 psi | 63% | 2572 fps | 95.5% |
| Bofors RP7 | <<locked>> | 80% | 41,205 psi | 63% | 2458 fps | 96.6% |
| Hodgdon H380 | <<locked>> | 80% | 47,253 psi | 73% | 2589 fps | 99.7% |
| Hodgdon H414 | <<locked>> | 80% | 42,366 psi | 65% | 2556 fps | 97.6% |
| Hodgdon H4350 | <<locked>> | 80% | 38,711 psi | 60% | 2438 fps | 95% |
| Hodgdon H4831 SC | <<locked>> | 96% | 50,024 psi | 77% | 2675 fps | 95.7% |
| Hodgdon H4895 | <<locked>> | 80% | 54,824 psi | 84% | 2689 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 33,837 psi | 52% | 2355 fps | 99.1% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 48,573 psi | 75% | 2631 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 98% | 40,132 psi | 62% | 2628 fps | 95.7% |
| Hodgdon Superformance | 51 gr | 80% | 38,014 psi | 59% | 2499 fps | 95.9% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,253 psi | 42% | 1487 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 48,646 psi | 75% | 2585 fps | 100% |
| IMR 3031 | <<locked>> | 80% | 51,097 psi | 79% | 2604 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 45,194 psi | 70% | 2520 fps | 99.9% |
| IMR 4166 Enduron | <<locked>> | 80% | 44,353 psi | 68% | 2493 fps | 97.9% |
| IMR 4350 | <<locked>> | 80% | 36,854 psi | 57% | 2388 fps | 95.2% |
| IMR 4451 Enduron | <<locked>> | 80% | 42,569 psi | 65% | 2484 fps | 97.4% |
| IMR 4831 | <<locked>> | 80% | 32,416 psi | 50% | 2325 fps | 97.3% |
| IMR 4895 | <<locked>> | 80% | 51,010 psi | 79% | 2658 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 92% | 46,688 psi | 72% | 2582 fps | 95% |
| IMR 7828 SSC | <<locked>> | 94% | 45,585 psi | 70% | 2660 fps | 95.2% |
| Lovex D073.6 | <<locked>> | 80% | 54,607 psi | 84% | 2655 fps | 100% |
| Lovex S060 | <<locked>> | 80% | 52,953 psi | 81% | 2606 fps | 100% |
| Lovex S062 | <<locked>> | 80% | 48,588 psi | 75% | 2569 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 40,248 psi | 62% | 2443 fps | 98.1% |
| Lovex S070 | <<locked>> | 80% | 38,464 psi | 59% | 2424 fps | 96.7% |
| Lovex S071 | <<locked>> | 90% | 32,358 psi | 50% | 2327 fps | 95.4% |
| Norma 201 | <<locked>> | 80% | 53,026 psi | 82% | 2626 fps | 100% |
| Norma 202 | <<locked>> | 80% | 53,505 psi | 82% | 2620 fps | 100% |
| Norma 203B | <<locked>> | 80% | 49,081 psi | 76% | 2619 fps | 100% |
| Norma 204 | <<locked>> | 84% | 41,379 psi | 64% | 2521 fps | 95.3% |
| Norma MRP | <<locked>> | 86% | 35,027 psi | 54% | 2474 fps | 95% |
| Norma URP | <<locked>> | 80% | 37,028 psi | 57% | 2441 fps | 98.4% |
| Ramshot Big Game | <<locked>> | 80% | 49,371 psi | 76% | 2642 fps | 100% |
| Ramshot Grand | <<locked>> | 92% | 44,715 psi | 69% | 2656 fps | 95.3% |
| Ramshot Hunter | <<locked>> | 80% | 35,839 psi | 55% | 2428 fps | 96.5% |
| Ramshot Magnum | <<locked>> | 92% | 38,711 psi | 60% | 2517 fps | 95.5% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,775 psi | 43% | 1523 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 47,108 psi | 73% | 2573 fps | 98.9% |
| ReloadSwiss RS 52 | <<locked>> | 80% | 53,751 psi | 83% | 2744 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 43,511 psi | 67% | 2620 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 36,898 psi | 57% | 2463 fps | 98.3% |
| ReloadSwiss RS 70 | 49 gr | 80% | 35,868 psi | 55% | 2469 fps | 97.7% |
| ReloadSwiss RS 76 | <<locked>> | 96% | 37,159 psi | 57% | 2556 fps | 95.7% |
| Rottweil R 902 | <<locked>> | 80% | 50,386 psi | 78% | 2579 fps | 100% |
| Rottweil R 903 | <<locked>> | 80% | 44,179 psi | 68% | 2528 fps | 100% |
| Rottweil R 904 | <<locked>> | 90% | 45,469 psi | 70% | 2566 fps | 95.4% |
| Rottweil R 905 | <<locked>> | 88% | 39,769 psi | 61% | 2510 fps | 95.3% |
| Rottweil R 907 | <<locked>> | 80% | 41,205 psi | 63% | 2458 fps | 96.6% |
| Shooters World Long Rifle | <<locked>> | 80% | 40,248 psi | 62% | 2443 fps | 98.1% |
| Shooters World Match Rifle | <<locked>> | 80% | 54,607 psi | 84% | 2655 fps | 100% |
| Shooters World Precision | <<locked>> | 80% | 48,588 psi | 75% | 2569 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 38,464 psi | 59% | 2425 fps | 96.7% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 45,237 psi | 70% | 2580 fps | 100% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 52,649 psi | 81% | 2654 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 53,780 psi | 83% | 2558 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 45,484 psi | 70% | 2436 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 39,349 psi | 61% | 2389 fps | 96.7% |
| SNPE Vectan Tubal 8000 | <<locked>> | 88% | 39,392 psi | 61% | 2507 fps | 95.1% |
| Somchem S335 | <<locked>> | 80% | 53,548 psi | 82% | 2558 fps | 100% |
| Somchem S341 | <<locked>> | 80% | 54,955 psi | 85% | 2673 fps | 100% |
| Somchem S355 | <<locked>> | 80% | 44,498 psi | 68% | 2527 fps | 100% |
| Somchem S361 | <<locked>> | 92% | 49,588 psi | 76% | 2611 fps | 95.5% |
| Somchem S365 | <<locked>> | 80% | 33,373 psi | 51% | 2399 fps | 99.8% |
| Somchem S385 | <<locked>> | 86% | 37,927 psi | 58% | 2445 fps | 95.6% |
| Unknown powder | <<locked>> | 80% | 39,885 psi | 61% | 2493 fps | 98.6% |
| Vihtavuori N133 | <<locked>> | 80% | 50,952 psi | 78% | 2500 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 50,821 psi | 78% | 2546 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 50,256 psi | 77% | 2552 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 38,159 psi | 59% | 2385 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 39,842 psi | 61% | 2466 fps | 98.9% |
| Vihtavuori N165 | <<locked>> | 92% | 38,435 psi | 59% | 2448 fps | 95.3% |
| Vihtavuori N540 | <<locked>> | 80% | 49,879 psi | 77% | 2575 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 40,553 psi | 62% | 2510 fps | 99% |
| Vihtavuori N555 | <<locked>> | 80% | 29,240 psi | 45% | 2297 fps | 96.7% |
| Vihtavuori N560 | <<locked>> | 96% | 46,920 psi | 72% | 2705 fps | 95.2% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 37,521 psi | 58% | 2412 fps | 99.8% |
| Winchester 760 | <<locked>> | 80% | 42,366 psi | 65% | 2556 fps | 97.6% |
| Winchester StaBALL HD | <<locked>> | 82% | 25,063 psi | 39% | 2255 fps | 96.4% |
| Winchester Supreme 780 | <<locked>> | 88% | 40,640 psi | 63% | 2497 fps | 95.2% |
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 103 powders for .280 Ackley Improved loaded with the .284 | 165gr | Sierra Tipped GameKing. Alliant Reloder-26 delivers the highest muzzle velocity at 2,924 fps; across all powders the maximum-charge window runs from 1,667 fps to 2,924 fps. Accurate 3100 gives the best case fill at 100 %, and 103 of the 103 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (448 MPa), the top charges use 57–90 %, leaving at least 10 % headroom. The 165.0 gr projectile in 0.284" calls for a 1:9.5 twist; slower twists will usually not stabilise this weight. Accurate 3100, ADI AR 2213, Alliant Reloder-22 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 Reloder-26, ReloadSwiss RS 70, Hodgdon Superformance rank at the top here: for .280 Ackley Improved with the .284 | 165gr | Sierra Tipped GameKing 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.