Load Specifications
Load data in caliber .280 Ackley Improved with .284 | 160gr | Speer Grand Slam bullet and 95 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.
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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 2495 | <<locked>> | 82% | 57,435 psi | 88% | 2694 fps | 100% |
| Accurate 2700 | <<locked>> | 84% | 58,349 psi | 90% | 2772 fps | 99.4% |
| Accurate 3100ᴾ | <<locked>> | 100% | 57,058 psi | 88% | 2822 fps | 99.9% |
| Accurate 4064 | <<locked>> | 84% | 58,117 psi | 89% | 2753 fps | 100% |
| Accurate 4350 | <<locked>> | 90% | 55,332 psi | 85% | 2815 fps | 100% |
| Accurate MAGPRO | <<locked>> | 98% | 55,405 psi | 85% | 2910 fps | 96.8% |
| ADI AR 2208 | <<locked>> | 86% | 57,783 psi | 89% | 2785 fps | 100% |
| ADI AR 2209 | <<locked>> | 96% | 56,130 psi | 86% | 2861 fps | 98.8% |
| ADI AR 2213ᴾ | <<locked>> | 100% | 57,609 psi | 89% | 2917 fps | 98.1% |
| Alliant Power Pro 2000-MR | <<locked>> | 82% | 57,638 psi | 89% | 2910 fps | 100% |
| Alliant Power Pro Varmint | <<locked>> | 96% | 56,217 psi | 86% | 2854 fps | 98.8% |
| Alliant Reloder- TS 15.5 | <<locked>> | 84% | 55,085 psi | 85% | 2756 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 82% | 55,187 psi | 85% | 2776 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 92% | 55,854 psi | 86% | 2867 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 88% | 57,363 psi | 88% | 2887 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 96% | 55,448 psi | 85% | 2848 fps | 98.7% |
| Alliant Reloder-22ᴾ | <<locked>> | 100% | 56,782 psi | 87% | 2910 fps | 99% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 53,519 psi | 82% | 2835 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 46,369 psi | 71% | 2769 fps | 99.7% |
| Alliant Reloder-26 | <<locked>> | 98% | 57,914 psi | 89% | 2979 fps | 100% |
| Bofors RP15ᴾ | <<locked>> | 100% | 51,866 psi | 80% | 2831 fps | 98.2% |
| Bofors RP3 | <<locked>> | 84% | 55,927 psi | 86% | 2772 fps | 100% |
| Bofors RP5ᴾ | <<locked>> | 100% | 56,782 psi | 87% | 2910 fps | 99% |
| Bofors RP7 | <<locked>> | 88% | 55,434 psi | 85% | 2766 fps | 99.3% |
| Hodgdon H1000ᴾ | <<locked>> | 100% | 46,122 psi | 71% | 2710 fps | 96.3% |
| Hodgdon H380 | <<locked>> | 84% | 56,318 psi | 87% | 2792 fps | 100% |
| Hodgdon H414 | <<locked>> | 90% | 57,203 psi | 88% | 2864 fps | 99.7% |
| Hodgdon H4350 | <<locked>> | 88% | 56,739 psi | 87% | 2822 fps | 99% |
| Hodgdon H4831 | <<locked>> | 98% | 57,624 psi | 89% | 2858 fps | 97.4% |
| Hodgdon H4831 SC | <<locked>> | 98% | 56,405 psi | 87% | 2838 fps | 97.2% |
| Hodgdon Hybrid 100V | <<locked>> | 94% | 56,463 psi | 87% | 2792 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 82% | 57,696 psi | 89% | 2822 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 45,484 psi | 70% | 2808 fps | 97.8% |
| Hodgdon Superformance | <<locked>> | 90% | 57,667 psi | 89% | 2904 fps | 99.7% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,738 psi | 57% | 1726 fps | 100% |
| Hodgdon VARGET | <<locked>> | 82% | 58,117 psi | 89% | 2785 fps | 100% |
| IMR 4064 | <<locked>> | 84% | 57,290 psi | 88% | 2766 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 82% | 55,985 psi | 86% | 2749 fps | 99.6% |
| IMR 4350 | <<locked>> | 92% | 56,289 psi | 87% | 2799 fps | 99.4% |
| IMR 4451 Enduron | <<locked>> | 88% | 56,855 psi | 87% | 2789 fps | 99.6% |
| IMR 4831 | <<locked>> | 92% | 55,782 psi | 86% | 2805 fps | 100% |
| IMR 4895 | <<locked>> | 82% | 56,637 psi | 87% | 2802 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 96% | 55,477 psi | 85% | 2789 fps | 97.2% |
| IMR 7828 SSCᴾ | <<locked>> | 100% | 54,998 psi | 85% | 2890 fps | 97.7% |
| Lovex S060 | <<locked>> | 82% | 58,566 psi | 90% | 2749 fps | 100% |
| Lovex S062 | <<locked>> | 84% | 57,551 psi | 89% | 2759 fps | 100% |
| Lovex S065 | <<locked>> | 90% | 57,116 psi | 88% | 2785 fps | 100% |
| Lovex S070 | <<locked>> | 92% | 58,494 psi | 90% | 2828 fps | 99.8% |
| Lovex S071ᴾ | <<locked>> | 100% | 47,369 psi | 73% | 2677 fps | 99.2% |
| Norma 201 | <<locked>> | 82% | 58,566 psi | 90% | 2766 fps | 100% |
| Norma 203B | <<locked>> | 84% | 58,247 psi | 90% | 2815 fps | 100% |
| Norma 204 | <<locked>> | 92% | 57,348 psi | 88% | 2854 fps | 98.8% |
| Norma MRP | <<locked>> | 98% | 56,391 psi | 87% | 2933 fps | 99.7% |
| Norma URP | <<locked>> | 92% | 57,450 psi | 88% | 2848 fps | 100% |
| Ramshot Big Game | <<locked>> | 82% | 55,550 psi | 85% | 2792 fps | 100% |
| Ramshot Grandᴾ | <<locked>> | 100% | 55,288 psi | 85% | 2904 fps | 98.1% |
| Ramshot Hunter | <<locked>> | 92% | 56,318 psi | 87% | 2854 fps | 99.9% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 49,516 psi | 76% | 2782 fps | 98.5% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,449 psi | 58% | 1765 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 84% | 56,202 psi | 86% | 2779 fps | 99.8% |
| ReloadSwiss RS 60 | <<locked>> | 86% | 56,811 psi | 87% | 2877 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 90% | 55,288 psi | 85% | 2838 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 92% | 57,217 psi | 88% | 2917 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 45,556 psi | 70% | 2805 fps | 98.7% |
| Rottweil R 902 | <<locked>> | 82% | 55,825 psi | 86% | 2720 fps | 100% |
| Rottweil R 903 | <<locked>> | 86% | 56,086 psi | 86% | 2769 fps | 100% |
| Rottweil R 904 | <<locked>> | 96% | 57,856 psi | 89% | 2831 fps | 98.1% |
| Rottweil R 905 | <<locked>> | 98% | 58,595 psi | 90% | 2890 fps | 99.2% |
| Rottweil R 907 | <<locked>> | 88% | 55,434 psi | 85% | 2766 fps | 99.3% |
| Shooters World Long Rifle | <<locked>> | 90% | 57,116 psi | 88% | 2785 fps | 100% |
| Shooters World Precision | <<locked>> | 84% | 57,551 psi | 89% | 2759 fps | 100% |
| Shooters World SW4350 | <<locked>> | 92% | 58,494 psi | 90% | 2828 fps | 99.8% |
| SNPE Vectan SP 11 | <<locked>> | 86% | 57,899 psi | 89% | 2831 fps | 100% |
| SNPE Vectan SP 9 | <<locked>> | 82% | 58,508 psi | 90% | 2799 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 86% | 56,782 psi | 87% | 2651 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 90% | 56,652 psi | 87% | 2740 fps | 99.6% |
| SNPE Vectan Tubal 8000 | <<locked>> | 98% | 58,102 psi | 89% | 2887 fps | 99.1% |
| Somchem S355 | <<locked>> | 86% | 56,130 psi | 86% | 2766 fps | 100% |
| Somchem S361 | <<locked>> | 94% | 55,956 psi | 86% | 2772 fps | 97.1% |
| Somchem S365 | <<locked>> | 94% | 57,276 psi | 88% | 2851 fps | 100% |
| Somchem S385 | <<locked>> | 96% | 55,564 psi | 85% | 2812 fps | 99.3% |
| Vihtavuori N135 | <<locked>> | 82% | 56,434 psi | 87% | 2677 fps | 100% |
| Vihtavuori N140 | <<locked>> | 82% | 56,507 psi | 87% | 2694 fps | 100% |
| Vihtavuori N150 | <<locked>> | 88% | 57,450 psi | 88% | 2740 fps | 100% |
| Vihtavuori N160 | <<locked>> | 90% | 55,999 psi | 86% | 2792 fps | 100% |
| Vihtavuori N165ᴾ | <<locked>> | 100% | 54,737 psi | 84% | 2785 fps | 99% |
| Vihtavuori N540 | <<locked>> | 84% | 58,160 psi | 89% | 2736 fps | 100% |
| Vihtavuori N550 | <<locked>> | 92% | 58,769 psi | 90% | 2848 fps | 100% |
| Vihtavuori N555 | <<locked>> | 98% | 56,333 psi | 87% | 2861 fps | 100% |
| Vihtavuori N560 | <<locked>> | 98% | 56,536 psi | 87% | 2927 fps | 97.6% |
| Vihtavuori N565ᴾ | <<locked>> | 100% | 48,457 psi | 75% | 2779 fps | 96.1% |
| Winchester 6.5 StaBALL | <<locked>> | 90% | 55,390 psi | 85% | 2756 fps | 100% |
| Winchester 760 | <<locked>> | 90% | 57,522 psi | 88% | 2867 fps | 99.7% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 49,139 psi | 76% | 2904 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 98% | 55,376 psi | 85% | 2805 fps | 98.6% |
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% | 53,882 psi | 83% | 2648 fps | 100% |
| Accurate 2700 | <<locked>> | 80% | 51,445 psi | 79% | 2667 fps | 98.6% |
| Accurate 3100 | <<locked>> | 84% | 33,243 psi | 51% | 2395 fps | 95.8% |
| Accurate 4064 | <<locked>> | 80% | 51,097 psi | 79% | 2654 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 39,320 psi | 60% | 2539 fps | 99% |
| Accurate MAGPRO | <<locked>> | 94% | 47,935 psi | 74% | 2782 fps | 95% |
| ADI AR 2208 | <<locked>> | 80% | 48,095 psi | 74% | 2638 fps | 100% |
| ADI AR 2209 | <<locked>> | 86% | 40,466 psi | 62% | 2575 fps | 95.2% |
| ADI AR 2213 | <<locked>> | 94% | 47,021 psi | 72% | 2733 fps | 95.7% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 53,447 psi | 82% | 2851 fps | 100% |
| Alliant Power Pro Varmint | <<locked>> | 86% | 40,625 psi | 63% | 2579 fps | 95.4% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 48,689 psi | 75% | 2661 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 51,909 psi | 80% | 2726 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 80% | 38,072 psi | 59% | 2549 fps | 99.1% |
| Alliant Reloder-17 | <<locked>> | 80% | 43,279 psi | 67% | 2667 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 86% | 40,248 psi | 62% | 2572 fps | 95.3% |
| Alliant Reloder-22 | <<locked>> | 90% | 40,567 psi | 62% | 2621 fps | 95.6% |
| Alliant Reloder-23 | <<locked>> | 80% | 27,992 psi | 43% | 2313 fps | 97.3% |
| Alliant Reloder-25 | <<locked>> | 88% | 31,821 psi | 49% | 2434 fps | 95.7% |
| Alliant Reloder-26 | 53.2 gr | 80% | 29,950 psi | 46% | 2421 fps | 95.7% |
| Bofors RP15 | <<locked>> | 92% | 40,016 psi | 62% | 2608 fps | 95.2% |
| Bofors RP3 | <<locked>> | 80% | 49,066 psi | 75% | 2671 fps | 100% |
| Bofors RP5 | <<locked>> | 90% | 40,567 psi | 62% | 2621 fps | 95.6% |
| Bofors RP7 | <<locked>> | 80% | 43,120 psi | 66% | 2552 fps | 97.2% |
| Hodgdon H1000 | <<locked>> | 98% | 42,989 psi | 66% | 2648 fps | 95.3% |
| Hodgdon H380 | <<locked>> | 80% | 49,458 psi | 76% | 2687 fps | 99.9% |
| Hodgdon H414 | <<locked>> | 80% | 41,191 psi | 63% | 2585 fps | 97.3% |
| Hodgdon H4350 | <<locked>> | 80% | 43,932 psi | 68% | 2602 fps | 96.7% |
| Hodgdon H4831 | <<locked>> | 92% | 47,050 psi | 72% | 2684 fps | 95.1% |
| Hodgdon H4831 SC | <<locked>> | 94% | 49,342 psi | 76% | 2723 fps | 95.7% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 35,708 psi | 55% | 2444 fps | 99.5% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 53,925 psi | 83% | 2772 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 96% | 39,914 psi | 61% | 2680 fps | 95.8% |
| Hodgdon Superformance | <<locked>> | 80% | 40,132 psi | 62% | 2598 fps | 96.7% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,427 psi | 42% | 1539 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 54,418 psi | 84% | 2733 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 50,618 psi | 78% | 2671 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 80% | 52,707 psi | 81% | 2700 fps | 99.3% |
| IMR 4350 | <<locked>> | 80% | 38,638 psi | 59% | 2480 fps | 96% |
| IMR 4451 Enduron | <<locked>> | 80% | 44,440 psi | 68% | 2579 fps | 97.9% |
| IMR 4831 | <<locked>> | 80% | 37,768 psi | 58% | 2493 fps | 98.8% |
| IMR 4895 | <<locked>> | 80% | 53,243 psi | 82% | 2753 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 90% | 45,992 psi | 71% | 2628 fps | 95% |
| IMR 7828 SSC | <<locked>> | 94% | 44,860 psi | 69% | 2707 fps | 95.2% |
| Lovex S060 | <<locked>> | 80% | 55,143 psi | 85% | 2700 fps | 100% |
| Lovex S062 | <<locked>> | 80% | 50,894 psi | 78% | 2664 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 41,974 psi | 65% | 2530 fps | 98.6% |
| Lovex S070 | <<locked>> | 80% | 40,350 psi | 62% | 2516 fps | 97.3% |
| Lovex S071 | <<locked>> | 88% | 32,329 psi | 50% | 2372 fps | 95.4% |
| Norma 201 | <<locked>> | 80% | 55,100 psi | 85% | 2717 fps | 100% |
| Norma 203B | <<locked>> | 80% | 51,256 psi | 79% | 2713 fps | 100% |
| Norma 204 | <<locked>> | 82% | 40,843 psi | 63% | 2566 fps | 95.3% |
| Norma MRP | 55.5 gr | 86% | 37,057 psi | 57% | 2575 fps | 95.9% |
| Norma URP | <<locked>> | 80% | 39,059 psi | 60% | 2536 fps | 98.9% |
| Ramshot Big Game | <<locked>> | 80% | 51,663 psi | 79% | 2736 fps | 100% |
| Ramshot Grand | <<locked>> | 94% | 44,788 psi | 69% | 2717 fps | 95.6% |
| Ramshot Hunter | <<locked>> | 80% | 37,739 psi | 58% | 2520 fps | 97.2% |
| Ramshot Magnum | <<locked>> | 92% | 37,130 psi | 57% | 2536 fps | 95% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,920 psi | 43% | 1575 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 49,342 psi | 76% | 2671 fps | 99.2% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 45,977 psi | 71% | 2717 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 39,146 psi | 60% | 2559 fps | 98.8% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 37,681 psi | 58% | 2566 fps | 98.3% |
| ReloadSwiss RS 76 | <<locked>> | 94% | 36,883 psi | 57% | 2605 fps | 95.8% |
| Rottweil R 902 | <<locked>> | 80% | 52,504 psi | 81% | 2671 fps | 100% |
| Rottweil R 903 | <<locked>> | 80% | 46,427 psi | 71% | 2621 fps | 100% |
| Rottweil R 904 | <<locked>> | 88% | 44,817 psi | 69% | 2615 fps | 95.3% |
| Rottweil R 905 | <<locked>> | 86% | 39,349 psi | 61% | 2556 fps | 95.2% |
| Rottweil R 907 | <<locked>> | 80% | 43,120 psi | 66% | 2552 fps | 97.2% |
| Shooters World Long Rifle | <<locked>> | 80% | 41,974 psi | 65% | 2530 fps | 98.6% |
| Shooters World Precision | <<locked>> | 80% | 50,894 psi | 78% | 2664 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 40,350 psi | 62% | 2516 fps | 97.3% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 47,384 psi | 73% | 2674 fps | 100% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 54,839 psi | 84% | 2746 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 47,297 psi | 73% | 2520 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 41,089 psi | 63% | 2477 fps | 97.3% |
| SNPE Vectan Tubal 8000 | <<locked>> | 86% | 38,986 psi | 60% | 2549 fps | 95.1% |
| Somchem S355 | <<locked>> | 80% | 46,441 psi | 71% | 2618 fps | 100% |
| Somchem S361 | <<locked>> | 90% | 48,863 psi | 75% | 2657 fps | 95.5% |
| Somchem S365 | <<locked>> | 80% | 35,447 psi | 55% | 2490 fps | 100% |
| Somchem S385 | <<locked>> | 84% | 37,420 psi | 58% | 2487 fps | 95.5% |
| Vihtavuori N135 | <<locked>> | 80% | 52,953 psi | 81% | 2635 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 53,156 psi | 82% | 2651 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 44,498 psi | 68% | 2549 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 40,393 psi | 62% | 2533 fps | 99.1% |
| Vihtavuori N165 | <<locked>> | 90% | 39,407 psi | 61% | 2520 fps | 95.8% |
| Vihtavuori N540 | <<locked>> | 80% | 51,314 psi | 79% | 2644 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 39,885 psi | 61% | 2533 fps | 98.9% |
| Vihtavuori N555 | <<locked>> | 80% | 31,053 psi | 48% | 2388 fps | 97.4% |
| Vihtavuori N560 | 59.4 gr | 92% | 46,035 psi | 71% | 2743 fps | 95.1% |
| Vihtavuori N565 | <<locked>> | 98% | 45,194 psi | 70% | 2720 fps | 95.2% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 39,450 psi | 61% | 2503 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 41,437 psi | 64% | 2592 fps | 97.4% |
| Winchester StaBALL HD | <<locked>> | 80% | 24,758 psi | 38% | 2290 fps | 96.2% |
| Winchester Supreme 780 | <<locked>> | 90% | 42,163 psi | 65% | 2582 fps | 95.9% |
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 95 powders for .280 Ackley Improved loaded with the .284 | 160gr | Speer Grand Slam. Alliant Reloder-26 delivers the highest muzzle velocity at 2,979 fps; across all powders the maximum-charge window runs from 1,726 fps to 2,979 fps. Accurate 3100 gives the best case fill at 100 %, and 95 of the 95 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 160.0 gr projectile in 0.284" calls for a 1:13.0 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, Norma MRP, Vihtavuori N560 rank at the top here: for .280 Ackley Improved with the .284 | 160gr | Speer Grand Slam 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.