Load Specifications
Load data in caliber .280 Ackley Improved with .284 | 168gr | Sierra MatchKing bullet and 93 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Alliant Reloder-26, Norma MRP and Vihtavuori N560.
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>> | 82% | 57,856 psi | 89% | 2625 fps | 100% |
| Accurate 2700 | <<locked>> | 82% | 55,071 psi | 85% | 2654 fps | 99.3% |
| Accurate 3100ᴾ | <<locked>> | 100% | 57,421 psi | 88% | 2759 fps | 100% |
| Accurate 4064 | <<locked>> | 84% | 58,392 psi | 90% | 2680 fps | 100% |
| Accurate 4350 | <<locked>> | 90% | 55,767 psi | 86% | 2749 fps | 100% |
| Accurate MAGPRO | <<locked>> | 98% | 55,753 psi | 86% | 2848 fps | 97.2% |
| ADI AR 2208 | <<locked>> | 86% | 58,102 psi | 89% | 2717 fps | 100% |
| ADI AR 2209 | <<locked>> | 96% | 56,536 psi | 87% | 2795 fps | 99.1% |
| ADI AR 2213ᴾ | <<locked>> | 100% | 57,696 psi | 89% | 2848 fps | 98.4% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 37,231 psi | 57% | 2523 fps | 96.6% |
| Alliant Power Pro 2000-MR | <<locked>> | 82% | 57,914 psi | 89% | 2838 fps | 100% |
| Alliant Reloder- TS 15.5 | <<locked>> | 84% | 55,622 psi | 86% | 2690 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 82% | 55,738 psi | 86% | 2713 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 92% | 56,579 psi | 87% | 2802 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 88% | 57,943 psi | 89% | 2822 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 96% | 55,883 psi | 86% | 2785 fps | 99% |
| Alliant Reloder-22ᴾ | <<locked>> | 100% | 56,884 psi | 88% | 2844 fps | 99.3% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 54,056 psi | 83% | 2769 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 46,920 psi | 72% | 2713 fps | 99.9% |
| Alliant Reloder-26 | <<locked>> | 98% | 58,334 psi | 90% | 2913 fps | 100% |
| Bofors RP15ᴾ | <<locked>> | 100% | 52,185 psi | 80% | 2769 fps | 98.6% |
| Bofors RP3 | <<locked>> | 84% | 56,347 psi | 87% | 2707 fps | 100% |
| Bofors RP30ᴾ | <<locked>> | 100% | 42,714 psi | 66% | 2638 fps | 95.9% |
| Bofors RP5ᴾ | <<locked>> | 100% | 56,884 psi | 88% | 2844 fps | 99.3% |
| Bofors RP7 | <<locked>> | 88% | 55,593 psi | 86% | 2700 fps | 99.5% |
| Hodgdon H1000ᴾ | <<locked>> | 100% | 46,470 psi | 71% | 2657 fps | 96.9% |
| Hodgdon H380 | <<locked>> | 84% | 56,739 psi | 87% | 2726 fps | 100% |
| Hodgdon H414 | <<locked>> | 90% | 57,754 psi | 89% | 2799 fps | 99.9% |
| Hodgdon H4350 | <<locked>> | 88% | 57,363 psi | 88% | 2762 fps | 99.3% |
| Hodgdon H4831 | <<locked>> | 98% | 58,001 psi | 89% | 2795 fps | 97.8% |
| Hodgdon H4831 SC | <<locked>> | 98% | 56,724 psi | 87% | 2776 fps | 97.6% |
| Hodgdon Hybrid 100V | <<locked>> | 94% | 56,913 psi | 88% | 2726 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 82% | 58,146 psi | 89% | 2756 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 45,818 psi | 70% | 2753 fps | 98.3% |
| Hodgdon Superformance | <<locked>> | 90% | 58,363 psi | 90% | 2844 fps | 99.8% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,637 psi | 56% | 1670 fps | 100% |
| Hodgdon VARGET | <<locked>> | 82% | 58,334 psi | 90% | 2713 fps | 100% |
| IMR 4064 | <<locked>> | 84% | 57,508 psi | 88% | 2697 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 82% | 56,492 psi | 87% | 2687 fps | 99.7% |
| IMR 4350 | <<locked>> | 92% | 56,739 psi | 87% | 2736 fps | 99.6% |
| IMR 4451 Enduron | <<locked>> | 88% | 57,334 psi | 88% | 2726 fps | 99.8% |
| IMR 4831 | <<locked>> | 92% | 55,956 psi | 86% | 2740 fps | 100% |
| IMR 4895 | <<locked>> | 82% | 57,174 psi | 88% | 2736 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 96% | 55,825 psi | 86% | 2726 fps | 97.6% |
| IMR 7828 SSCᴾ | <<locked>> | 100% | 55,390 psi | 85% | 2825 fps | 98.1% |
| Lovex S062 | <<locked>> | 84% | 57,769 psi | 89% | 2690 fps | 100% |
| Lovex S065 | <<locked>> | 90% | 57,392 psi | 88% | 2720 fps | 100% |
| Lovex S070 | <<locked>> | 90% | 55,405 psi | 85% | 2713 fps | 99.8% |
| Lovex S071ᴾ | <<locked>> | 100% | 47,718 psi | 73% | 2618 fps | 99.5% |
| Norma 203B | <<locked>> | 84% | 58,581 psi | 90% | 2746 fps | 100% |
| Norma 204 | <<locked>> | 92% | 57,711 psi | 89% | 2789 fps | 99.1% |
| Norma MRP | <<locked>> | 98% | 56,927 psi | 88% | 2874 fps | 99.9% |
| Norma URP | <<locked>> | 92% | 57,943 psi | 89% | 2782 fps | 100% |
| Ramshot Big Game | <<locked>> | 82% | 55,767 psi | 86% | 2723 fps | 100% |
| Ramshot Grandᴾ | <<locked>> | 100% | 55,912 psi | 86% | 2844 fps | 98.5% |
| Ramshot Hunter | <<locked>> | 92% | 56,681 psi | 87% | 2789 fps | 100% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 49,835 psi | 77% | 2723 fps | 98.9% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,376 psi | 58% | 1713 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 84% | 56,449 psi | 87% | 2710 fps | 99.9% |
| ReloadSwiss RS 60 | <<locked>> | 86% | 57,246 psi | 88% | 2808 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 90% | 55,622 psi | 86% | 2772 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 92% | 57,754 psi | 89% | 2854 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 45,934 psi | 71% | 2749 fps | 99.1% |
| Rottweil R 902 | <<locked>> | 82% | 56,217 psi | 86% | 2651 fps | 100% |
| Rottweil R 903 | <<locked>> | 86% | 56,521 psi | 87% | 2703 fps | 100% |
| Rottweil R 904 | <<locked>> | 96% | 58,175 psi | 89% | 2766 fps | 98.4% |
| Rottweil R 905 | <<locked>> | 98% | 58,798 psi | 90% | 2822 fps | 99.4% |
| Rottweil R 907 | <<locked>> | 88% | 55,593 psi | 86% | 2700 fps | 99.5% |
| Shooters World Long Rifle | <<locked>> | 90% | 57,392 psi | 88% | 2720 fps | 100% |
| Shooters World Precision | <<locked>> | 84% | 57,769 psi | 89% | 2690 fps | 100% |
| Shooters World SW4350 | <<locked>> | 90% | 55,405 psi | 85% | 2713 fps | 99.8% |
| SNPE Vectan SP 11 | <<locked>> | 86% | 58,204 psi | 90% | 2762 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 86% | 57,232 psi | 88% | 2585 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 90% | 57,058 psi | 88% | 2677 fps | 99.8% |
| SNPE Vectan Tubal 8000 | <<locked>> | 98% | 58,334 psi | 90% | 2818 fps | 99.3% |
| Somchem S355 | <<locked>> | 86% | 56,521 psi | 87% | 2700 fps | 100% |
| Somchem S361 | <<locked>> | 94% | 56,260 psi | 87% | 2710 fps | 97.5% |
| Somchem S365 | <<locked>> | 94% | 57,653 psi | 89% | 2782 fps | 100% |
| Somchem S385 | <<locked>> | 96% | 55,753 psi | 86% | 2746 fps | 99.5% |
| Vihtavuori N135 | <<locked>> | 82% | 56,724 psi | 87% | 2608 fps | 100% |
| Vihtavuori N140 | <<locked>> | 82% | 56,956 psi | 88% | 2628 fps | 100% |
| Vihtavuori N150 | <<locked>> | 88% | 57,653 psi | 89% | 2671 fps | 100% |
| Vihtavuori N160 | <<locked>> | 90% | 56,391 psi | 87% | 2726 fps | 100% |
| Vihtavuori N165ᴾ | <<locked>> | 100% | 55,129 psi | 85% | 2726 fps | 99.2% |
| Vihtavuori N540 | <<locked>> | 84% | 58,581 psi | 90% | 2671 fps | 100% |
| Vihtavuori N550 | <<locked>> | 90% | 55,564 psi | 85% | 2733 fps | 100% |
| Vihtavuori N555 | <<locked>> | 98% | 56,478 psi | 87% | 2795 fps | 100% |
| Vihtavuori N560 | <<locked>> | 98% | 57,029 psi | 88% | 2864 fps | 98% |
| Vihtavuori N565ᴾ | <<locked>> | 100% | 48,675 psi | 75% | 2717 fps | 96.6% |
| Winchester 6.5 StaBALL | <<locked>> | 90% | 55,854 psi | 86% | 2690 fps | 100% |
| Winchester 760 | <<locked>> | 90% | 58,030 psi | 89% | 2805 fps | 99.9% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 49,835 psi | 77% | 2841 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 98% | 55,753 psi | 86% | 2743 fps | 98.9% |
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% | 54,520 psi | 84% | 2582 fps | 100% |
| Accurate 2700 | <<locked>> | 80% | 51,721 psi | 80% | 2605 fps | 98.9% |
| Accurate 3100 | <<locked>> | 82% | 31,328 psi | 48% | 2293 fps | 95.5% |
| Accurate 4064 | <<locked>> | 80% | 51,721 psi | 80% | 2592 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 39,711 psi | 61% | 2487 fps | 99.3% |
| Accurate MAGPRO | <<locked>> | 94% | 48,544 psi | 75% | 2730 fps | 95.6% |
| ADI AR 2208 | <<locked>> | 80% | 48,327 psi | 74% | 2572 fps | 100% |
| ADI AR 2209 | <<locked>> | 86% | 40,770 psi | 63% | 2523 fps | 95.8% |
| ADI AR 2213 | <<locked>> | 92% | 44,353 psi | 68% | 2621 fps | 95.4% |
| ADI AR 2225 | <<locked>> | 98% | 34,954 psi | 54% | 2467 fps | 95.6% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 53,911 psi | 83% | 2782 fps | 100% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 49,037 psi | 75% | 2595 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 52,330 psi | 81% | 2661 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 80% | 38,348 psi | 59% | 2490 fps | 99.4% |
| Alliant Reloder-17 | <<locked>> | 80% | 43,598 psi | 67% | 2608 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 84% | 38,058 psi | 59% | 2464 fps | 95% |
| Alliant Reloder-22 | <<locked>> | 88% | 38,334 psi | 59% | 2513 fps | 95.3% |
| Alliant Reloder-23 | <<locked>> | 80% | 28,398 psi | 44% | 2270 fps | 97.9% |
| Alliant Reloder-25 | <<locked>> | 86% | 30,052 psi | 46% | 2329 fps | 95.3% |
| Alliant Reloder-26 | 51.6 gr | 80% | 30,284 psi | 47% | 2379 fps | 96.5% |
| Bofors RP15 | <<locked>> | 92% | 40,379 psi | 62% | 2556 fps | 95.8% |
| Bofors RP3 | <<locked>> | 80% | 49,516 psi | 76% | 2608 fps | 100% |
| Bofors RP30 | <<locked>> | 98% | 40,001 psi | 62% | 2582 fps | 95% |
| Bofors RP5 | <<locked>> | 88% | 38,334 psi | 59% | 2513 fps | 95.3% |
| Bofors RP7 | <<locked>> | 80% | 43,366 psi | 67% | 2493 fps | 97.6% |
| Hodgdon H1000 | <<locked>> | 96% | 40,683 psi | 63% | 2539 fps | 95% |
| Hodgdon H380 | <<locked>> | 80% | 49,676 psi | 76% | 2621 fps | 99.9% |
| Hodgdon H414 | <<locked>> | 80% | 41,437 psi | 64% | 2526 fps | 97.8% |
| Hodgdon H4350 | <<locked>> | 80% | 44,353 psi | 68% | 2546 fps | 97.2% |
| Hodgdon H4831 | <<locked>> | 92% | 47,558 psi | 73% | 2628 fps | 95.7% |
| Hodgdon H4831 SC | <<locked>> | 92% | 46,485 psi | 72% | 2608 fps | 95.4% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 35,984 psi | 55% | 2388 fps | 99.7% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 54,288 psi | 84% | 2703 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 94% | 37,811 psi | 58% | 2572 fps | 95.5% |
| Hodgdon Superformance | <<locked>> | 80% | 40,393 psi | 62% | 2543 fps | 97.2% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,485 psi | 42% | 1493 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 54,781 psi | 84% | 2667 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 50,865 psi | 78% | 2605 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 80% | 53,084 psi | 82% | 2638 fps | 99.5% |
| IMR 4350 | <<locked>> | 80% | 38,943 psi | 60% | 2425 fps | 96.5% |
| IMR 4451 Enduron | <<locked>> | 80% | 44,730 psi | 69% | 2520 fps | 98.3% |
| IMR 4831 | <<locked>> | 80% | 38,087 psi | 59% | 2441 fps | 99.1% |
| IMR 4895 | <<locked>> | 80% | 53,679 psi | 83% | 2687 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 90% | 46,311 psi | 71% | 2572 fps | 95.6% |
| IMR 7828 SSC | <<locked>> | 94% | 45,165 psi | 69% | 2648 fps | 95.8% |
| Lovex S062 | <<locked>> | 80% | 51,169 psi | 79% | 2598 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 42,467 psi | 65% | 2477 fps | 98.9% |
| Lovex S070 | <<locked>> | 80% | 40,640 psi | 63% | 2461 fps | 97.7% |
| Lovex S071 | <<locked>> | 86% | 30,632 psi | 47% | 2274 fps | 95.2% |
| Norma 203B | <<locked>> | 80% | 51,663 psi | 79% | 2648 fps | 100% |
| Norma 204 | <<locked>> | 82% | 41,162 psi | 63% | 2510 fps | 95.8% |
| Norma MRP | 52.6 gr | 84% | 35,027 psi | 54% | 2467 fps | 95.6% |
| Norma URP | <<locked>> | 80% | 39,378 psi | 61% | 2480 fps | 99.2% |
| Ramshot Big Game | <<locked>> | 80% | 52,083 psi | 80% | 2671 fps | 100% |
| Ramshot Grand | <<locked>> | 92% | 42,018 psi | 65% | 2598 fps | 95.2% |
| Ramshot Hunter | <<locked>> | 80% | 38,189 psi | 59% | 2470 fps | 97.7% |
| Ramshot Magnum | <<locked>> | 92% | 37,449 psi | 58% | 2487 fps | 95.7% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,007 psi | 43% | 1529 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 49,603 psi | 76% | 2608 fps | 99.5% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 46,296 psi | 71% | 2654 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 39,450 psi | 61% | 2503 fps | 99.1% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 38,014 psi | 58% | 2513 fps | 98.7% |
| ReloadSwiss RS 76 | <<locked>> | 92% | 34,708 psi | 53% | 2493 fps | 95.3% |
| Rottweil R 902 | <<locked>> | 80% | 53,011 psi | 82% | 2608 fps | 100% |
| Rottweil R 903 | <<locked>> | 80% | 46,775 psi | 72% | 2559 fps | 100% |
| Rottweil R 904 | <<locked>> | 86% | 42,424 psi | 65% | 2507 fps | 95.1% |
| Rottweil R 905 | <<locked>> | 84% | 37,159 psi | 57% | 2448 fps | 95% |
| Rottweil R 907 | <<locked>> | 80% | 43,366 psi | 67% | 2493 fps | 97.6% |
| Shooters World Long Rifle | <<locked>> | 80% | 42,467 psi | 65% | 2477 fps | 98.9% |
| Shooters World Precision | <<locked>> | 80% | 51,169 psi | 79% | 2598 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 40,640 psi | 63% | 2461 fps | 97.7% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 47,935 psi | 74% | 2612 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 47,674 psi | 73% | 2457 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 41,437 psi | 64% | 2425 fps | 97.7% |
| SNPE Vectan Tubal 8000 | <<locked>> | 86% | 39,363 psi | 61% | 2497 fps | 95.7% |
| Somchem S355 | <<locked>> | 80% | 46,963 psi | 72% | 2559 fps | 100% |
| Somchem S361 | <<locked>> | 88% | 46,021 psi | 71% | 2546 fps | 95.2% |
| Somchem S365 | <<locked>> | 80% | 35,810 psi | 55% | 2438 fps | 100% |
| Somchem S385 | <<locked>> | 82% | 35,360 psi | 54% | 2379 fps | 95.2% |
| Vihtavuori N135 | <<locked>> | 80% | 53,447 psi | 82% | 2569 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 53,505 psi | 82% | 2582 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 44,817 psi | 69% | 2490 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 40,727 psi | 63% | 2474 fps | 99.4% |
| Vihtavuori N165 | <<locked>> | 88% | 37,188 psi | 57% | 2415 fps | 95.5% |
| Vihtavuori N540 | <<locked>> | 80% | 51,517 psi | 79% | 2579 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 40,089 psi | 62% | 2477 fps | 99.2% |
| Vihtavuori N555 | <<locked>> | 80% | 31,531 psi | 49% | 2343 fps | 98% |
| Vihtavuori N560 | 57.6 gr | 92% | 46,398 psi | 71% | 2687 fps | 95.7% |
| Vihtavuori N565 | <<locked>> | 98% | 45,571 psi | 70% | 2664 fps | 95.8% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 39,581 psi | 61% | 2444 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 41,640 psi | 64% | 2533 fps | 97.8% |
| Winchester StaBALL HD | <<locked>> | 80% | 25,063 psi | 39% | 2254 fps | 97.2% |
| Winchester Supreme 780 | <<locked>> | 88% | 39,595 psi | 61% | 2470 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 93 powders for .280 Ackley Improved loaded with the .284 | 168gr | Sierra MatchKing. Alliant Reloder-26 delivers the highest muzzle velocity at 2,913 fps; across all powders the maximum-charge window runs from 1,670 fps to 2,913 fps. Accurate 3100 gives the best case fill at 100 %, and 93 of the 93 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (448 MPa), the top charges use 56–90 %, leaving at least 10 % headroom. The 168.0 gr projectile in 0.284" calls for a 1:10.5 twist; slower twists will usually not stabilise this weight. Accurate 3100, ADI AR 2213, ADI AR 2225 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, Norma MRP, Vihtavuori N560 rank at the top here: for .280 Ackley Improved with the .284 | 168gr | Sierra MatchKing 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.