Load Specifications
Load data in caliber .280 Ackley Improved with .284 | 170gr | Norma ORYX bullet and 89 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Norma MRP, Vihtavuori N560 and Accurate MAGPRO.
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 2700 | <<locked>> | 82% | 56,492 psi | 87% | 2667 fps | 99.5% |
| Accurate 3100 | <<locked>> | 98% | 55,753 psi | 86% | 2726 fps | 100% |
| Accurate 4064 | <<locked>> | 82% | 56,608 psi | 87% | 2644 fps | 100% |
| Accurate 4350 | <<locked>> | 90% | 57,812 psi | 89% | 2766 fps | 100% |
| Accurate MAGPRO | <<locked>> | 98% | 58,117 psi | 89% | 2874 fps | 97.9% |
| ADI AR 2208 | <<locked>> | 84% | 56,115 psi | 86% | 2680 fps | 100% |
| ADI AR 2209 | <<locked>> | 96% | 58,305 psi | 90% | 2812 fps | 99.4% |
| ADI AR 2213 | <<locked>> | 98% | 55,854 psi | 86% | 2812 fps | 98.3% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 38,566 psi | 59% | 2549 fps | 97.5% |
| Alliant Reloder- TS 15.5 | <<locked>> | 84% | 56,971 psi | 88% | 2697 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 82% | 57,377 psi | 88% | 2723 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 92% | 58,305 psi | 90% | 2812 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 86% | 55,985 psi | 86% | 2782 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 96% | 57,580 psi | 89% | 2799 fps | 99.3% |
| Alliant Reloder-22 | <<locked>> | 98% | 55,317 psi | 85% | 2808 fps | 99.2% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 56,318 psi | 87% | 2785 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 48,660 psi | 75% | 2733 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 96% | 56,753 psi | 87% | 2877 fps | 100% |
| Baschieri & Pellagri 109ᴾ | <<locked>> | 100% | 58,247 psi | 90% | 2776 fps | 95.9% |
| Bofors RP15ᴾ | <<locked>> | 100% | 54,157 psi | 83% | 2789 fps | 99% |
| Bofors RP3 | <<locked>> | 84% | 58,030 psi | 89% | 2713 fps | 100% |
| Bofors RP30ᴾ | <<locked>> | 100% | 44,498 psi | 68% | 2661 fps | 96.7% |
| Bofors RP5 | <<locked>> | 98% | 55,317 psi | 85% | 2808 fps | 99.2% |
| Bofors RP7 | <<locked>> | 88% | 57,058 psi | 88% | 2710 fps | 99.7% |
| Hodgdon H1000ᴾ | <<locked>> | 100% | 48,066 psi | 74% | 2677 fps | 97.6% |
| Hodgdon H380 | <<locked>> | 84% | 58,305 psi | 90% | 2736 fps | 100% |
| Hodgdon H414 | <<locked>> | 88% | 55,738 psi | 86% | 2762 fps | 99.8% |
| Hodgdon H4350 | <<locked>> | 86% | 55,376 psi | 85% | 2723 fps | 99.2% |
| Hodgdon H4831 | <<locked>> | 96% | 56,202 psi | 86% | 2759 fps | 97.8% |
| Hodgdon H4831 SC | <<locked>> | 98% | 58,711 psi | 90% | 2795 fps | 98.2% |
| Hodgdon Hybrid 100V | <<locked>> | 94% | 58,552 psi | 90% | 2736 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 47,529 psi | 73% | 2779 fps | 98.9% |
| Hodgdon Superformance | <<locked>> | 88% | 56,115 psi | 86% | 2802 fps | 99.8% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,898 psi | 57% | 1673 fps | 100% |
| IMR 4064 | <<locked>> | 82% | 55,535 psi | 85% | 2661 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 82% | 57,972 psi | 89% | 2700 fps | 99.9% |
| IMR 4350 | <<locked>> | 92% | 58,436 psi | 90% | 2749 fps | 99.8% |
| IMR 4451 Enduron | <<locked>> | 88% | 58,726 psi | 90% | 2736 fps | 99.9% |
| IMR 4831 | <<locked>> | 92% | 57,856 psi | 89% | 2753 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 96% | 57,348 psi | 88% | 2743 fps | 98.1% |
| IMR 7828 SSCᴾ | <<locked>> | 100% | 57,363 psi | 88% | 2848 fps | 98.7% |
| Lovex S062 | <<locked>> | 82% | 55,869 psi | 86% | 2651 fps | 100% |
| Lovex S065 | <<locked>> | 88% | 55,709 psi | 86% | 2684 fps | 100% |
| Lovex S070 | <<locked>> | 90% | 57,116 psi | 88% | 2730 fps | 99.9% |
| Lovex S071ᴾ | <<locked>> | 100% | 49,734 psi | 77% | 2638 fps | 99.7% |
| Norma 203B | <<locked>> | 82% | 56,666 psi | 87% | 2710 fps | 100% |
| Norma 204 | <<locked>> | 90% | 55,811 psi | 86% | 2753 fps | 99% |
| Norma MRP | <<locked>> | 96% | 55,085 psi | 85% | 2835 fps | 99.8% |
| Norma URP | <<locked>> | 90% | 56,217 psi | 86% | 2746 fps | 100% |
| Ramshot Big Game | <<locked>> | 82% | 57,392 psi | 88% | 2733 fps | 100% |
| Ramshot Grandᴾ | <<locked>> | 100% | 57,928 psi | 89% | 2864 fps | 99% |
| Ramshot Hunter | <<locked>> | 92% | 58,494 psi | 90% | 2802 fps | 100% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 51,953 psi | 80% | 2746 fps | 99.3% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,652 psi | 58% | 1713 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 84% | 58,204 psi | 90% | 2726 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 84% | 55,361 psi | 85% | 2769 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 90% | 57,566 psi | 89% | 2785 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 90% | 55,898 psi | 86% | 2815 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 47,790 psi | 74% | 2779 fps | 99.6% |
| Rottweil R 902 | <<locked>> | 82% | 57,841 psi | 89% | 2664 fps | 100% |
| Rottweil R 903 | <<locked>> | 86% | 58,218 psi | 90% | 2713 fps | 100% |
| Rottweil R 904 | <<locked>> | 94% | 56,246 psi | 87% | 2730 fps | 98.4% |
| Rottweil R 905 | <<locked>> | 96% | 57,145 psi | 88% | 2792 fps | 99.4% |
| Rottweil R 907 | <<locked>> | 88% | 57,058 psi | 88% | 2710 fps | 99.7% |
| Shooters World Long Rifle | <<locked>> | 88% | 55,709 psi | 86% | 2684 fps | 100% |
| Shooters World Precision | <<locked>> | 82% | 55,869 psi | 86% | 2651 fps | 100% |
| Shooters World SW4350 | <<locked>> | 90% | 57,116 psi | 88% | 2730 fps | 99.9% |
| SNPE Vectan SP 11 | <<locked>> | 84% | 56,289 psi | 87% | 2726 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 86% | 58,508 psi | 90% | 2589 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 90% | 58,711 psi | 90% | 2690 fps | 99.9% |
| SNPE Vectan Tubal 8000 | <<locked>> | 96% | 56,681 psi | 87% | 2785 fps | 99.3% |
| Somchem S355 | <<locked>> | 86% | 58,102 psi | 89% | 2710 fps | 100% |
| Somchem S361 | <<locked>> | 94% | 58,001 psi | 89% | 2726 fps | 98% |
| Somchem S365 | <<locked>> | 92% | 55,970 psi | 86% | 2746 fps | 100% |
| Somchem S385 | <<locked>> | 96% | 57,754 psi | 89% | 2766 fps | 99.7% |
| Vihtavuori N135 | <<locked>> | 82% | 58,247 psi | 90% | 2615 fps | 100% |
| Vihtavuori N140 | <<locked>> | 82% | 58,320 psi | 90% | 2631 fps | 100% |
| Vihtavuori N150 | <<locked>> | 86% | 55,637 psi | 86% | 2635 fps | 100% |
| Vihtavuori N160 | <<locked>> | 90% | 58,247 psi | 90% | 2740 fps | 100% |
| Vihtavuori N165ᴾ | <<locked>> | 100% | 57,087 psi | 88% | 2743 fps | 99.5% |
| Vihtavuori N540 | <<locked>> | 82% | 56,608 psi | 87% | 2635 fps | 100% |
| Vihtavuori N550 | <<locked>> | 90% | 57,334 psi | 88% | 2746 fps | 100% |
| Vihtavuori N555 | <<locked>> | 98% | 58,784 psi | 90% | 2812 fps | 100% |
| Vihtavuori N560 | <<locked>> | 96% | 55,158 psi | 85% | 2825 fps | 97.9% |
| Vihtavuori N565ᴾ | <<locked>> | 100% | 50,894 psi | 78% | 2746 fps | 97.4% |
| Winchester 6.5 StaBALL | <<locked>> | 90% | 57,798 psi | 89% | 2707 fps | 100% |
| Winchester 760 | <<locked>> | 88% | 56,028 psi | 86% | 2766 fps | 99.8% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 52,431 psi | 81% | 2861 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 98% | 57,725 psi | 89% | 2759 fps | 99.3% |
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 2700 | <<locked>> | 80% | 53,127 psi | 82% | 2618 fps | 99.2% |
| Accurate 3100 | <<locked>> | 80% | 30,356 psi | 47% | 2254 fps | 95.3% |
| Accurate 4064 | <<locked>> | 80% | 53,200 psi | 82% | 2602 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 41,060 psi | 63% | 2500 fps | 99.6% |
| Accurate MAGPRO | 59.9 gr | 92% | 46,818 psi | 72% | 2690 fps | 95.4% |
| ADI AR 2208 | <<locked>> | 80% | 49,617 psi | 76% | 2582 fps | 100% |
| ADI AR 2209 | <<locked>> | 84% | 39,450 psi | 61% | 2487 fps | 95.7% |
| ADI AR 2213 | <<locked>> | 90% | 42,960 psi | 66% | 2585 fps | 95.3% |
| ADI AR 2225 | <<locked>> | 96% | 34,113 psi | 52% | 2438 fps | 95.5% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 50,357 psi | 77% | 2605 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 53,664 psi | 83% | 2671 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 80% | 39,755 psi | 61% | 2510 fps | 99.7% |
| Alliant Reloder-17 | <<locked>> | 80% | 45,208 psi | 70% | 2621 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 84% | 39,334 psi | 61% | 2480 fps | 95.8% |
| Alliant Reloder-22 | <<locked>> | 86% | 37,173 psi | 57% | 2477 fps | 95.2% |
| Alliant Reloder-23 | <<locked>> | 80% | 29,370 psi | 45% | 2287 fps | 98.5% |
| Alliant Reloder-25 | <<locked>> | 84% | 29,182 psi | 45% | 2297 fps | 95.2% |
| Alliant Reloder-26 | <<locked>> | 80% | 31,430 psi | 48% | 2402 fps | 97.3% |
| Baschieri & Pellagri 109 | <<locked>> | 98% | 54,766 psi | 84% | 2720 fps | 95.1% |
| Bofors RP15 | <<locked>> | 90% | 39,349 psi | 61% | 2523 fps | 95.8% |
| Bofors RP3 | <<locked>> | 80% | 51,169 psi | 79% | 2621 fps | 100% |
| Bofors RP30 | <<locked>> | 98% | 41,713 psi | 64% | 2605 fps | 95.9% |
| Bofors RP5 | <<locked>> | 86% | 37,173 psi | 57% | 2477 fps | 95.2% |
| Bofors RP7 | <<locked>> | 80% | 44,541 psi | 69% | 2507 fps | 98.1% |
| Hodgdon H1000 | <<locked>> | 96% | 41,959 psi | 65% | 2562 fps | 95.9% |
| Hodgdon H380 | <<locked>> | 80% | 51,242 psi | 79% | 2635 fps | 100% |
| Hodgdon H414 | <<locked>> | 80% | 42,902 psi | 66% | 2546 fps | 98.3% |
| Hodgdon H4350 | <<locked>> | 80% | 45,759 psi | 70% | 2562 fps | 97.8% |
| Hodgdon H4831 | <<locked>> | 90% | 45,803 psi | 70% | 2589 fps | 95.5% |
| Hodgdon H4831 SC | <<locked>> | 90% | 45,049 psi | 69% | 2575 fps | 95.3% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 37,231 psi | 57% | 2402 fps | 99.9% |
| Hodgdon Retumbo | <<locked>> | 92% | 36,753 psi | 57% | 2539 fps | 95.4% |
| Hodgdon Superformance | <<locked>> | 80% | 41,901 psi | 64% | 2566 fps | 97.8% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,485 psi | 42% | 1490 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 52,170 psi | 80% | 2615 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 80% | 54,288 psi | 84% | 2648 fps | 99.7% |
| IMR 4350 | <<locked>> | 80% | 40,205 psi | 62% | 2444 fps | 97.1% |
| IMR 4451 Enduron | <<locked>> | 80% | 45,832 psi | 71% | 2533 fps | 98.7% |
| IMR 4831 | <<locked>> | 80% | 39,334 psi | 61% | 2454 fps | 99.4% |
| IMR 4955 Enduron | <<locked>> | 88% | 44,672 psi | 69% | 2533 fps | 95.4% |
| IMR 7828 SSC | <<locked>> | 92% | 43,787 psi | 67% | 2615 fps | 95.7% |
| Lovex S062 | <<locked>> | 80% | 52,547 psi | 81% | 2608 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 43,613 psi | 67% | 2490 fps | 99.2% |
| Lovex S070 | <<locked>> | 80% | 41,800 psi | 64% | 2474 fps | 98.2% |
| Lovex S071 | <<locked>> | 84% | 29,834 psi | 46% | 2241 fps | 95.1% |
| Norma 203B | <<locked>> | 80% | 53,011 psi | 82% | 2657 fps | 100% |
| Norma 204 | <<locked>> | 80% | 39,682 psi | 61% | 2470 fps | 95.7% |
| Norma MRP | 52.4 gr | 82% | 33,808 psi | 52% | 2425 fps | 95.4% |
| Norma URP | <<locked>> | 80% | 40,640 psi | 63% | 2493 fps | 99.5% |
| Ramshot Big Game | <<locked>> | 80% | 53,650 psi | 83% | 2684 fps | 100% |
| Ramshot Grand | <<locked>> | 90% | 40,727 psi | 63% | 2566 fps | 95.1% |
| Ramshot Hunter | <<locked>> | 80% | 39,363 psi | 61% | 2484 fps | 98.2% |
| Ramshot Magnum | <<locked>> | 90% | 36,129 psi | 56% | 2448 fps | 95.5% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,007 psi | 43% | 1526 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 51,024 psi | 78% | 2621 fps | 99.7% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 47,993 psi | 74% | 2667 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 40,944 psi | 63% | 2520 fps | 99.4% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 39,291 psi | 60% | 2530 fps | 99.1% |
| ReloadSwiss RS 76 | <<locked>> | 90% | 33,678 psi | 52% | 2457 fps | 95.1% |
| Rottweil R 902 | <<locked>> | 80% | 54,360 psi | 84% | 2618 fps | 100% |
| Rottweil R 903 | <<locked>> | 80% | 48,124 psi | 74% | 2569 fps | 100% |
| Rottweil R 904 | <<locked>> | 84% | 41,046 psi | 63% | 2470 fps | 95% |
| Rottweil R 905 | <<locked>> | 84% | 38,508 psi | 59% | 2467 fps | 95.7% |
| Rottweil R 907 | <<locked>> | 80% | 44,541 psi | 69% | 2507 fps | 98.1% |
| Shooters World Long Rifle | <<locked>> | 80% | 43,613 psi | 67% | 2490 fps | 99.2% |
| Shooters World Precision | <<locked>> | 80% | 52,547 psi | 81% | 2608 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 41,800 psi | 64% | 2474 fps | 98.2% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 49,211 psi | 76% | 2621 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 48,936 psi | 75% | 2467 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 42,496 psi | 65% | 2434 fps | 98.2% |
| SNPE Vectan Tubal 8000 | <<locked>> | 84% | 38,159 psi | 59% | 2461 fps | 95.6% |
| Somchem S355 | <<locked>> | 80% | 48,283 psi | 74% | 2569 fps | 100% |
| Somchem S361 | <<locked>> | 86% | 44,411 psi | 68% | 2510 fps | 95.1% |
| Somchem S365 | <<locked>> | 80% | 37,333 psi | 57% | 2454 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 34,374 psi | 53% | 2346 fps | 95.1% |
| Vihtavuori N135 | <<locked>> | 80% | 54,984 psi | 85% | 2575 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 54,824 psi | 84% | 2589 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 46,050 psi | 71% | 2497 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 41,974 psi | 65% | 2487 fps | 99.6% |
| Vihtavuori N165 | <<locked>> | 86% | 36,056 psi | 55% | 2379 fps | 95.3% |
| Vihtavuori N540 | <<locked>> | 80% | 53,026 psi | 82% | 2589 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 41,437 psi | 64% | 2493 fps | 99.5% |
| Vihtavuori N555 | <<locked>> | 80% | 32,764 psi | 50% | 2359 fps | 98.5% |
| Vihtavuori N560 | 57.6 gr | 90% | 45,049 psi | 69% | 2651 fps | 95.6% |
| Vihtavuori N565 | <<locked>> | 96% | 44,222 psi | 68% | 2628 fps | 95.7% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 41,060 psi | 63% | 2457 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 43,105 psi | 66% | 2549 fps | 98.3% |
| Winchester StaBALL HD | <<locked>> | 80% | 25,889 psi | 40% | 2277 fps | 98.1% |
| Winchester Supreme 780 | <<locked>> | 86% | 38,261 psi | 59% | 2434 fps | 95.4% |
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 94 powders for .280 Ackley Improved loaded with the .284 | 170gr | Norma ORYX. Alliant Reloder-26 delivers the highest muzzle velocity at 2,877 fps; across all powders the maximum-charge window runs from 1,673 fps to 2,877 fps. ADI AR 2217 gives the best case fill at 100 %, and 94 of the 94 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (448 MPa), the top charges use 53–90 %, leaving at least 10 % headroom. The 170.0 gr projectile in 0.284" calls for a 1:12.5 twist; slower twists will usually not stabilise this weight. ADI AR 2217, ADI AR 2225, 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. Norma MRP, Vihtavuori N560, Accurate MAGPRO rank at the top here: for .280 Ackley Improved with the .284 | 170gr | Norma ORYX they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, IMR 8133 Enduron, ReloadSwiss RS 80, Vihtavuori N568 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.