Load Specifications
Load data in caliber .280 Ackley Improved with .284 | 160gr | Swift A-Frame bullet and 98 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are ReloadSwiss RS 70, Alliant Reloder-26 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>> | 82% | 56,362 psi | 87% | 2674 fps | 100% |
| Accurate 2700 | <<locked>> | 84% | 57,101 psi | 88% | 2746 fps | 99.2% |
| Accurate 3100ᴾ | <<locked>> | 100% | 55,317 psi | 85% | 2792 fps | 99.8% |
| Accurate 4064 | <<locked>> | 84% | 56,521 psi | 87% | 2726 fps | 100% |
| Accurate 4350 | <<locked>> | 92% | 57,638 psi | 89% | 2841 fps | 100% |
| Accurate MAGPROᴾ | <<locked>> | 100% | 57,508 psi | 88% | 2936 fps | 97% |
| ADI AR 2206H | <<locked>> | 82% | 58,784 psi | 90% | 2802 fps | 100% |
| ADI AR 2208 | <<locked>> | 86% | 56,420 psi | 87% | 2759 fps | 100% |
| ADI AR 2209 | <<locked>> | 98% | 58,436 psi | 90% | 2887 fps | 98.9% |
| ADI AR 2213ᴾ | <<locked>> | 100% | 56,043 psi | 86% | 2884 fps | 97.6% |
| Alliant Power Pro 2000-MR | <<locked>> | 82% | 56,101 psi | 86% | 2884 fps | 100% |
| Alliant Reloder- TS 15.5 | <<locked>> | 86% | 57,406 psi | 88% | 2782 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 84% | 57,493 psi | 88% | 2802 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 94% | 58,160 psi | 89% | 2890 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 88% | 55,927 psi | 86% | 2864 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 98% | 57,624 psi | 89% | 2874 fps | 98.9% |
| Alliant Reloder-22ᴾ | <<locked>> | 100% | 55,056 psi | 85% | 2877 fps | 98.7% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 51,982 psi | 80% | 2808 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 45,194 psi | 70% | 2740 fps | 99.5% |
| Alliant Reloder-26 | <<locked>> | 98% | 55,680 psi | 86% | 2943 fps | 100% |
| Bofors RP15ᴾ | <<locked>> | 100% | 50,473 psi | 78% | 2802 fps | 97.8% |
| Bofors RP3 | <<locked>> | 86% | 58,392 psi | 90% | 2799 fps | 100% |
| Bofors RP5ᴾ | <<locked>> | 100% | 55,056 psi | 85% | 2877 fps | 98.7% |
| Bofors RP7 | <<locked>> | 90% | 57,682 psi | 89% | 2792 fps | 99.4% |
| Hodgdon H380 | <<locked>> | 86% | 58,813 psi | 90% | 2818 fps | 100% |
| Hodgdon H414 | <<locked>> | 90% | 55,985 psi | 86% | 2838 fps | 99.6% |
| Hodgdon H4350 | <<locked>> | 88% | 55,506 psi | 85% | 2795 fps | 98.8% |
| Hodgdon H4831 | <<locked>> | 98% | 56,043 psi | 86% | 2825 fps | 97% |
| Hodgdon H4831 SC | <<locked>> | 98% | 54,810 psi | 84% | 2805 fps | 96.7% |
| Hodgdon Hybrid 100V | <<locked>> | 96% | 58,523 psi | 90% | 2812 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 82% | 56,246 psi | 87% | 2795 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 44,106 psi | 68% | 2769 fps | 97.2% |
| Hodgdon Superformance | <<locked>> | 90% | 56,217 psi | 86% | 2877 fps | 99.5% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,637 psi | 56% | 1713 fps | 100% |
| Hodgdon VARGET | <<locked>> | 82% | 56,985 psi | 88% | 2762 fps | 100% |
| IMR 4064 | <<locked>> | 84% | 56,144 psi | 86% | 2746 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 84% | 58,465 psi | 90% | 2779 fps | 99.7% |
| IMR 4350 | <<locked>> | 94% | 58,653 psi | 90% | 2822 fps | 99.5% |
| IMR 4451 Enduron | <<locked>> | 88% | 55,622 psi | 86% | 2762 fps | 99.4% |
| IMR 4831 | <<locked>> | 94% | 57,798 psi | 89% | 2828 fps | 100% |
| IMR 4895 | <<locked>> | 82% | 55,448 psi | 85% | 2779 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 98% | 57,682 psi | 89% | 2815 fps | 97.4% |
| IMR 7828 SSCᴾ | <<locked>> | 100% | 53,447 psi | 82% | 2854 fps | 97.2% |
| Lovex S060 | <<locked>> | 82% | 57,464 psi | 88% | 2726 fps | 100% |
| Lovex S062 | <<locked>> | 84% | 56,376 psi | 87% | 2736 fps | 100% |
| Lovex S065 | <<locked>> | 90% | 55,869 psi | 86% | 2759 fps | 99.9% |
| Lovex S070 | <<locked>> | 92% | 57,305 psi | 88% | 2805 fps | 99.7% |
| Lovex S071ᴾ | <<locked>> | 100% | 45,934 psi | 71% | 2648 fps | 99% |
| Norma 201 | <<locked>> | 82% | 57,653 psi | 89% | 2746 fps | 100% |
| Norma 202 | <<locked>> | 82% | 58,204 psi | 90% | 2736 fps | 100% |
| Norma 203B | <<locked>> | 84% | 56,782 psi | 87% | 2789 fps | 100% |
| Norma 204 | <<locked>> | 92% | 55,869 psi | 86% | 2825 fps | 98.5% |
| Norma MRPᴾ | <<locked>> | 100% | 58,421 psi | 90% | 2959 fps | 99.8% |
| Norma URP | <<locked>> | 92% | 56,115 psi | 86% | 2822 fps | 100% |
| Ramshot Big Game | <<locked>> | 84% | 58,001 psi | 89% | 2818 fps | 100% |
| Ramshot Grandᴾ | <<locked>> | 100% | 53,751 psi | 83% | 2871 fps | 97.7% |
| Ramshot Hunter | <<locked>> | 94% | 58,421 psi | 90% | 2877 fps | 100% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 48,109 psi | 74% | 2749 fps | 98.1% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,115 psi | 57% | 1752 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 86% | 58,465 psi | 90% | 2805 fps | 99.9% |
| ReloadSwiss RS 60 | <<locked>> | 86% | 55,317 psi | 85% | 2854 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 92% | 57,276 psi | 88% | 2861 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 92% | 55,782 psi | 86% | 2890 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 44,106 psi | 68% | 2766 fps | 98.2% |
| Rottweil R 902 | <<locked>> | 84% | 58,117 psi | 89% | 2743 fps | 100% |
| Rottweil R 903 | <<locked>> | 88% | 58,552 psi | 90% | 2795 fps | 100% |
| Rottweil R 904 | <<locked>> | 96% | 56,449 psi | 87% | 2802 fps | 97.7% |
| Rottweil R 905 | <<locked>> | 98% | 57,087 psi | 88% | 2861 fps | 98.9% |
| Rottweil R 907 | <<locked>> | 90% | 57,682 psi | 89% | 2792 fps | 99.4% |
| Shooters World Long Rifle | <<locked>> | 90% | 55,869 psi | 86% | 2759 fps | 99.9% |
| Shooters World Precision | <<locked>> | 84% | 56,376 psi | 87% | 2736 fps | 100% |
| Shooters World SW4350 | <<locked>> | 92% | 57,305 psi | 88% | 2805 fps | 99.7% |
| SNPE Vectan SP 11 | <<locked>> | 86% | 56,260 psi | 87% | 2802 fps | 100% |
| SNPE Vectan SP 9 | <<locked>> | 82% | 57,421 psi | 88% | 2776 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 82% | 58,073 psi | 89% | 2671 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 86% | 55,666 psi | 86% | 2631 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 90% | 55,564 psi | 85% | 2717 fps | 99.5% |
| SNPE Vectan Tubal 8000 | <<locked>> | 98% | 56,594 psi | 87% | 2858 fps | 98.8% |
| Somchem S335 | <<locked>> | 82% | 58,001 psi | 89% | 2671 fps | 100% |
| Somchem S355 | <<locked>> | 88% | 58,262 psi | 90% | 2789 fps | 100% |
| Somchem S361 | <<locked>> | 96% | 58,305 psi | 90% | 2795 fps | 97.3% |
| Somchem S365 | <<locked>> | 94% | 55,579 psi | 86% | 2825 fps | 100% |
| Somchem S385 | <<locked>> | 98% | 57,450 psi | 88% | 2831 fps | 99.4% |
| Vihtavuori N133 | <<locked>> | 82% | 58,639 psi | 90% | 2651 fps | 100% |
| Vihtavuori N135 | <<locked>> | 84% | 58,755 psi | 90% | 2700 fps | 100% |
| Vihtavuori N140 | <<locked>> | 82% | 55,332 psi | 85% | 2671 fps | 100% |
| Vihtavuori N150 | <<locked>> | 88% | 56,101 psi | 86% | 2717 fps | 100% |
| Vihtavuori N160 | <<locked>> | 92% | 58,305 psi | 90% | 2818 fps | 100% |
| Vihtavuori N165ᴾ | <<locked>> | 100% | 53,185 psi | 82% | 2756 fps | 98.7% |
| Vihtavuori N540 | <<locked>> | 84% | 56,869 psi | 87% | 2713 fps | 100% |
| Vihtavuori N550 | <<locked>> | 92% | 57,334 psi | 88% | 2822 fps | 100% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 58,088 psi | 89% | 2881 fps | 100% |
| Vihtavuori N560ᴾ | <<locked>> | 100% | 58,595 psi | 90% | 2949 fps | 97.8% |
| Winchester 6.5 StaBALL | <<locked>> | 92% | 57,885 psi | 89% | 2782 fps | 100% |
| Winchester 760 | <<locked>> | 90% | 55,985 psi | 86% | 2838 fps | 99.6% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 47,079 psi | 72% | 2871 fps | 100% |
| Winchester StaBALL Match | <<locked>> | 82% | 57,464 psi | 88% | 2782 fps | 100% |
| Winchester Supreme 780ᴾ | <<locked>> | 100% | 57,899 psi | 89% | 2831 fps | 98.8% |
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% | 52,837 psi | 81% | 2628 fps | 100% |
| Accurate 2700 | <<locked>> | 80% | 50,198 psi | 77% | 2638 fps | 98.3% |
| Accurate 3100 | <<locked>> | 84% | 32,126 psi | 49% | 2362 fps | 95.2% |
| Accurate 4064 | <<locked>> | 80% | 50,067 psi | 77% | 2635 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 38,189 psi | 59% | 2513 fps | 98.7% |
| Accurate MAGPRO | <<locked>> | 96% | 49,763 psi | 77% | 2808 fps | 95.3% |
| ADI AR 2206H | <<locked>> | 80% | 55,216 psi | 85% | 2749 fps | 100% |
| ADI AR 2208 | <<locked>> | 80% | 46,992 psi | 72% | 2612 fps | 99.9% |
| ADI AR 2209 | <<locked>> | 88% | 42,235 psi | 65% | 2608 fps | 95.6% |
| ADI AR 2213 | <<locked>> | 94% | 45,818 psi | 70% | 2703 fps | 95.1% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 52,214 psi | 80% | 2825 fps | 100% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 47,529 psi | 73% | 2635 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 50,734 psi | 78% | 2703 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 80% | 37,231 psi | 57% | 2523 fps | 98.8% |
| Alliant Reloder-17 | <<locked>> | 80% | 42,206 psi | 65% | 2644 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 88% | 41,930 psi | 65% | 2602 fps | 95.7% |
| Alliant Reloder-22 | <<locked>> | 90% | 39,479 psi | 61% | 2592 fps | 95% |
| Alliant Reloder-23 | <<locked>> | 80% | 27,340 psi | 42% | 2290 fps | 96.8% |
| Alliant Reloder-25 | <<locked>> | 88% | 30,966 psi | 48% | 2402 fps | 95% |
| Alliant Reloder-26 | 52 gr | 80% | 29,182 psi | 45% | 2395 fps | 95.1% |
| Bofors RP15 | <<locked>> | 94% | 41,582 psi | 64% | 2638 fps | 95.6% |
| Bofors RP3 | <<locked>> | 80% | 48,109 psi | 74% | 2648 fps | 100% |
| Bofors RP5 | <<locked>> | 90% | 39,479 psi | 61% | 2592 fps | 95% |
| Bofors RP7 | <<locked>> | 80% | 42,105 psi | 65% | 2523 fps | 96.8% |
| Hodgdon H380 | <<locked>> | 80% | 48,370 psi | 74% | 2661 fps | 99.8% |
| Hodgdon H414 | <<locked>> | 80% | 40,176 psi | 62% | 2559 fps | 96.9% |
| Hodgdon H4350 | <<locked>> | 80% | 43,178 psi | 66% | 2579 fps | 96.4% |
| Hodgdon H4831 | <<locked>> | 94% | 49,124 psi | 76% | 2713 fps | 95.4% |
| Hodgdon H4831 SC | <<locked>> | 94% | 48,066 psi | 74% | 2694 fps | 95.2% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 34,867 psi | 54% | 2421 fps | 99.3% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 52,794 psi | 81% | 2746 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 96% | 38,870 psi | 60% | 2648 fps | 95.1% |
| Hodgdon Superformance | 53.6 gr | 80% | 39,102 psi | 60% | 2569 fps | 96.2% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,340 psi | 42% | 1529 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 53,548 psi | 82% | 2713 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 49,458 psi | 76% | 2644 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 80% | 51,663 psi | 79% | 2674 fps | 99.1% |
| IMR 4350 | <<locked>> | 80% | 37,869 psi | 58% | 2457 fps | 95.5% |
| IMR 4451 Enduron | <<locked>> | 80% | 43,439 psi | 67% | 2552 fps | 97.6% |
| IMR 4831 | <<locked>> | 80% | 36,738 psi | 57% | 2467 fps | 98.5% |
| IMR 4895 | <<locked>> | 80% | 52,054 psi | 80% | 2726 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 92% | 47,892 psi | 74% | 2654 fps | 95.3% |
| IMR 7828 SSC | <<locked>> | 96% | 46,630 psi | 72% | 2733 fps | 95.5% |
| Lovex S060 | <<locked>> | 80% | 54,012 psi | 83% | 2677 fps | 100% |
| Lovex S062 | <<locked>> | 80% | 49,705 psi | 76% | 2638 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 41,176 psi | 63% | 2510 fps | 98.3% |
| Lovex S070 | <<locked>> | 80% | 39,349 psi | 61% | 2490 fps | 96.9% |
| Lovex S071 | <<locked>> | 90% | 33,402 psi | 51% | 2395 fps | 95.7% |
| Norma 201 | <<locked>> | 80% | 54,143 psi | 83% | 2697 fps | 100% |
| Norma 202 | <<locked>> | 80% | 54,636 psi | 84% | 2690 fps | 100% |
| Norma 203B | <<locked>> | 80% | 50,096 psi | 77% | 2687 fps | 100% |
| Norma 204 | <<locked>> | 84% | 42,641 psi | 66% | 2595 fps | 95.7% |
| Norma MRP | <<locked>> | 86% | 36,027 psi | 55% | 2546 fps | 95.3% |
| Norma URP | <<locked>> | 80% | 37,985 psi | 58% | 2507 fps | 98.6% |
| Ramshot Big Game | <<locked>> | 80% | 50,618 psi | 78% | 2713 fps | 100% |
| Ramshot Grand | <<locked>> | 96% | 46,601 psi | 72% | 2746 fps | 95.9% |
| Ramshot Hunter | <<locked>> | 80% | 36,796 psi | 57% | 2493 fps | 96.8% |
| Ramshot Magnum | <<locked>> | 94% | 38,551 psi | 59% | 2562 fps | 95.4% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,833 psi | 43% | 1565 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 48,327 psi | 74% | 2644 fps | 99% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 44,817 psi | 69% | 2694 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 37,884 psi | 58% | 2530 fps | 98.4% |
| ReloadSwiss RS 70 | 51.5 gr | 80% | 36,825 psi | 57% | 2539 fps | 97.9% |
| ReloadSwiss RS 76 | <<locked>> | 96% | 38,334 psi | 59% | 2631 fps | 96.2% |
| Rottweil R 902 | <<locked>> | 80% | 51,561 psi | 79% | 2651 fps | 100% |
| Rottweil R 903 | <<locked>> | 80% | 45,223 psi | 70% | 2595 fps | 100% |
| Rottweil R 904 | <<locked>> | 90% | 46,601 psi | 72% | 2641 fps | 95.7% |
| Rottweil R 905 | <<locked>> | 88% | 41,031 psi | 63% | 2585 fps | 95.6% |
| Rottweil R 907 | <<locked>> | 80% | 42,105 psi | 65% | 2523 fps | 96.8% |
| Shooters World Long Rifle | <<locked>> | 80% | 41,176 psi | 63% | 2510 fps | 98.3% |
| Shooters World Precision | <<locked>> | 80% | 49,705 psi | 76% | 2638 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 39,349 psi | 61% | 2490 fps | 96.9% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 46,311 psi | 71% | 2648 fps | 100% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 53,766 psi | 83% | 2723 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 54,752 psi | 84% | 2625 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 46,354 psi | 71% | 2500 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 40,190 psi | 62% | 2454 fps | 96.9% |
| SNPE Vectan Tubal 8000 | <<locked>> | 88% | 40,654 psi | 63% | 2579 fps | 95.5% |
| Somchem S335 | <<locked>> | 80% | 54,592 psi | 84% | 2625 fps | 100% |
| Somchem S355 | <<locked>> | 80% | 45,527 psi | 70% | 2595 fps | 100% |
| Somchem S361 | <<locked>> | 90% | 47,703 psi | 73% | 2631 fps | 95% |
| Somchem S365 | <<locked>> | 80% | 34,534 psi | 53% | 2467 fps | 99.9% |
| Somchem S385 | <<locked>> | 84% | 36,506 psi | 56% | 2461 fps | 95% |
| Vihtavuori N133 | <<locked>> | 80% | 55,317 psi | 85% | 2608 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 51,895 psi | 80% | 2612 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 51,967 psi | 80% | 2628 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 43,395 psi | 67% | 2526 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 39,320 psi | 60% | 2507 fps | 98.8% |
| Vihtavuori N165 | <<locked>> | 90% | 38,377 psi | 59% | 2493 fps | 95.2% |
| Vihtavuori N540 | <<locked>> | 80% | 50,256 psi | 77% | 2625 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 38,856 psi | 60% | 2510 fps | 98.6% |
| Vihtavuori N555 | <<locked>> | 80% | 30,211 psi | 46% | 2362 fps | 96.9% |
| Vihtavuori N560 | <<locked>> | 94% | 47,993 psi | 74% | 2772 fps | 95.5% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 38,421 psi | 59% | 2477 fps | 99.9% |
| Winchester 760 | <<locked>> | 80% | 40,176 psi | 62% | 2559 fps | 96.9% |
| Winchester StaBALL HD | <<locked>> | 80% | 24,120 psi | 37% | 2257 fps | 95.4% |
| Winchester StaBALL Match | <<locked>> | 80% | 54,012 psi | 83% | 2736 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 90% | 40,886 psi | 63% | 2549 fps | 95.3% |
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 105 powders for .280 Ackley Improved loaded with the .284 | 160gr | Swift A-Frame. Norma MRP delivers the highest muzzle velocity at 2,959 fps; across all powders the maximum-charge window runs from 1,713 fps to 2,959 fps. Accurate 3100 gives the best case fill at 100 %, and 105 of the 105 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (448 MPa), the top charges use 49–90 %, leaving at least 10 % headroom. The 160.0 gr projectile in 0.284" calls for a 1:11.5 twist; slower twists will usually not stabilise this weight. Accurate 3100, Accurate MAGPRO, ADI AR 2213 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. ReloadSwiss RS 70, Alliant Reloder-26, Hodgdon Superformance rank at the top here: for .280 Ackley Improved with the .284 | 160gr | Swift A-Frame they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, ADI AR 2217, Baschieri & Pellagri 109, Bofors RP30 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.