Load Specifications
Load data in caliber .280 Ackley Improved with .284 | 150gr | Norma FMJ SemiP bullet and 102 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 Alliant Reloder-16.
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>> | 84% | 58,566 psi | 90% | 2799 fps | 100% |
| Accurate 2700 | <<locked>> | 84% | 56,101 psi | 86% | 2822 fps | 98.8% |
| Accurate 3100ᴾ | <<locked>> | 100% | 53,882 psi | 83% | 2861 fps | 99.6% |
| Accurate 4064 | <<locked>> | 84% | 55,347 psi | 85% | 2805 fps | 100% |
| Accurate 4350 | <<locked>> | 92% | 56,072 psi | 86% | 2913 fps | 100% |
| Accurate MAGPROᴾ | <<locked>> | 100% | 55,956 psi | 86% | 2999 fps | 96.1% |
| ADI AR 2206H | <<locked>> | 82% | 57,653 psi | 89% | 2881 fps | 100% |
| ADI AR 2208 | <<locked>> | 88% | 58,769 psi | 90% | 2887 fps | 100% |
| ADI AR 2209 | <<locked>> | 98% | 57,000 psi | 88% | 2956 fps | 98.4% |
| ADI AR 2213ᴾ | <<locked>> | 100% | 54,795 psi | 84% | 2949 fps | 96.8% |
| Alliant Power Pro 2000-MR | <<locked>> | 84% | 58,726 psi | 90% | 3018 fps | 100% |
| Alliant Reloder- TS 15.5 | <<locked>> | 86% | 56,130 psi | 86% | 2858 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 84% | 56,565 psi | 87% | 2884 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 94% | 56,637 psi | 87% | 2966 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 90% | 58,276 psi | 90% | 2992 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 98% | 56,449 psi | 87% | 2946 fps | 98.3% |
| Alliant Reloder-22ᴾ | <<locked>> | 100% | 53,635 psi | 83% | 2946 fps | 98.1% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 50,459 psi | 78% | 2877 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 44,106 psi | 68% | 2805 fps | 99% |
| Alliant Reloder-26ᴾ | <<locked>> | 100% | 58,610 psi | 90% | 3081 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 82% | 57,827 psi | 89% | 2904 fps | 100% |
| Bofors RP15ᴾ | <<locked>> | 100% | 49,008 psi | 75% | 2864 fps | 97% |
| Bofors RP3 | <<locked>> | 86% | 57,203 psi | 88% | 2881 fps | 100% |
| Bofors RP5ᴾ | <<locked>> | 100% | 53,635 psi | 83% | 2946 fps | 98.1% |
| Bofors RP7 | <<locked>> | 90% | 56,579 psi | 87% | 2864 fps | 99% |
| Hodgdon H380 | <<locked>> | 86% | 57,667 psi | 89% | 2897 fps | 100% |
| Hodgdon H414 | <<locked>> | 92% | 58,291 psi | 90% | 2966 fps | 99.5% |
| Hodgdon H4350 | <<locked>> | 90% | 58,015 psi | 89% | 2923 fps | 98.7% |
| Hodgdon H4831ᴾ | <<locked>> | 100% | 58,798 psi | 90% | 2953 fps | 96.9% |
| Hodgdon H4831 SCᴾ | <<locked>> | 100% | 57,522 psi | 88% | 2936 fps | 96.7% |
| Hodgdon H4895 | <<locked>> | 82% | 58,363 psi | 90% | 2890 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 96% | 57,246 psi | 88% | 2894 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 82% | 55,143 psi | 85% | 2877 fps | 100% |
| Hodgdon Superformance | <<locked>> | 90% | 54,868 psi | 84% | 2946 fps | 99% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,361 psi | 56% | 1775 fps | 100% |
| Hodgdon VARGET | <<locked>> | 82% | 55,956 psi | 86% | 2844 fps | 100% |
| IMR 4064 | <<locked>> | 86% | 58,262 psi | 90% | 2871 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 84% | 57,595 psi | 89% | 2858 fps | 99.4% |
| IMR 4350 | <<locked>> | 94% | 57,537 psi | 89% | 2897 fps | 99.1% |
| IMR 4451 Enduron | <<locked>> | 90% | 58,015 psi | 89% | 2890 fps | 99.4% |
| IMR 4831 | <<locked>> | 94% | 56,507 psi | 87% | 2904 fps | 100% |
| IMR 4895 | <<locked>> | 84% | 58,015 psi | 89% | 2913 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 98% | 56,405 psi | 87% | 2881 fps | 96.7% |
| IMR 7828 SSCᴾ | <<locked>> | 100% | 52,199 psi | 80% | 2920 fps | 96.4% |
| Lovex D073.6 | <<locked>> | 82% | 58,465 psi | 90% | 2854 fps | 100% |
| Lovex S060 | <<locked>> | 82% | 56,304 psi | 87% | 2805 fps | 100% |
| Lovex S062 | <<locked>> | 86% | 58,726 psi | 90% | 2864 fps | 100% |
| Lovex S065 | <<locked>> | 92% | 58,204 psi | 90% | 2887 fps | 99.9% |
| Lovex S070 | <<locked>> | 92% | 55,985 psi | 86% | 2874 fps | 99.4% |
| Lovex S071ᴾ | <<locked>> | 100% | 44,744 psi | 69% | 2710 fps | 98.4% |
| Norma 201 | <<locked>> | 82% | 56,391 psi | 87% | 2825 fps | 100% |
| Norma 202 | <<locked>> | 82% | 57,174 psi | 88% | 2822 fps | 100% |
| Norma 203B | <<locked>> | 84% | 55,854 psi | 86% | 2871 fps | 100% |
| Norma 204 | <<locked>> | 94% | 58,508 psi | 90% | 2953 fps | 98.4% |
| Norma MRPᴾ | <<locked>> | 100% | 56,971 psi | 88% | 3031 fps | 99.5% |
| Norma URP | <<locked>> | 94% | 58,291 psi | 90% | 2949 fps | 100% |
| Ramshot Big Game | <<locked>> | 84% | 56,695 psi | 87% | 2897 fps | 100% |
| Ramshot Grandᴾ | <<locked>> | 100% | 52,518 psi | 81% | 2933 fps | 96.8% |
| Ramshot Hunter | <<locked>> | 94% | 57,246 psi | 88% | 2953 fps | 99.8% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 46,630 psi | 72% | 2805 fps | 97.2% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,014 psi | 57% | 1818 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 86% | 57,305 psi | 88% | 2877 fps | 99.6% |
| ReloadSwiss RS 52 | <<locked>> | 82% | 57,653 psi | 89% | 2953 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 88% | 57,725 psi | 89% | 2986 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 92% | 56,072 psi | 86% | 2936 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 94% | 58,450 psi | 90% | 3025 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 42,975 psi | 66% | 2818 fps | 97.2% |
| Rottweil R 902 | <<locked>> | 84% | 57,116 psi | 88% | 2825 fps | 100% |
| Rottweil R 903 | <<locked>> | 88% | 57,058 psi | 88% | 2871 fps | 100% |
| Rottweil R 904 | <<locked>> | 98% | 58,813 psi | 90% | 2927 fps | 97.7% |
| Rottweil R 905 | <<locked>> | 98% | 55,593 psi | 86% | 2930 fps | 98.3% |
| Rottweil R 907 | <<locked>> | 90% | 56,579 psi | 87% | 2864 fps | 99% |
| Shooters World Long Rifle | <<locked>> | 92% | 58,204 psi | 90% | 2887 fps | 99.9% |
| Shooters World Match Rifle | <<locked>> | 82% | 58,465 psi | 90% | 2854 fps | 100% |
| Shooters World Precision | <<locked>> | 86% | 58,726 psi | 90% | 2864 fps | 100% |
| Shooters World SW4350 | <<locked>> | 92% | 55,985 psi | 86% | 2874 fps | 99.4% |
| SNPE Vectan SP 11 | <<locked>> | 88% | 58,813 psi | 90% | 2933 fps | 100% |
| SNPE Vectan SP 9 | <<locked>> | 82% | 56,231 psi | 87% | 2858 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 82% | 57,334 psi | 88% | 2756 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 88% | 58,189 psi | 90% | 2756 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 92% | 58,160 psi | 89% | 2841 fps | 99.4% |
| SNPE Vectan Tubal 8000ᴾ | <<locked>> | 100% | 58,755 psi | 90% | 2979 fps | 98.7% |
| Somchem S335 | <<locked>> | 82% | 56,826 psi | 87% | 2749 fps | 100% |
| Somchem S355 | <<locked>> | 88% | 57,232 psi | 88% | 2871 fps | 100% |
| Somchem S361 | <<locked>> | 96% | 56,985 psi | 88% | 2864 fps | 96.5% |
| Somchem S365 | <<locked>> | 96% | 57,798 psi | 89% | 2949 fps | 100% |
| Somchem S385 | <<locked>> | 98% | 56,173 psi | 86% | 2904 fps | 99% |
| Vihtavuori N133 | <<locked>> | 82% | 57,812 psi | 89% | 2736 fps | 100% |
| Vihtavuori N135 | <<locked>> | 84% | 57,406 psi | 88% | 2782 fps | 100% |
| Vihtavuori N140 | <<locked>> | 84% | 57,725 psi | 89% | 2799 fps | 100% |
| Vihtavuori N150 | <<locked>> | 90% | 58,595 psi | 90% | 2844 fps | 100% |
| Vihtavuori N160 | <<locked>> | 92% | 56,840 psi | 87% | 2890 fps | 100% |
| Vihtavuori N165ᴾ | <<locked>> | 100% | 51,953 psi | 80% | 2825 fps | 98.1% |
| Vihtavuori N540 | <<locked>> | 84% | 55,883 psi | 86% | 2795 fps | 100% |
| Vihtavuori N550 | <<locked>> | 92% | 56,057 psi | 86% | 2897 fps | 100% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 56,681 psi | 87% | 2956 fps | 100% |
| Vihtavuori N560ᴾ | <<locked>> | 100% | 57,276 psi | 88% | 3018 fps | 97% |
| Winchester 6.5 StaBALL | <<locked>> | 92% | 56,652 psi | 87% | 2858 fps | 100% |
| Winchester 760 | <<locked>> | 92% | 58,610 psi | 90% | 2972 fps | 99.6% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 45,672 psi | 70% | 2936 fps | 100% |
| Winchester StaBALL Match | <<locked>> | 82% | 56,405 psi | 87% | 2861 fps | 100% |
| Winchester Supreme 780ᴾ | <<locked>> | 100% | 56,420 psi | 87% | 2900 fps | 98.2% |
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% | 51,590 psi | 79% | 2703 fps | 100% |
| Accurate 2700 | <<locked>> | 80% | 49,182 psi | 76% | 2707 fps | 97.7% |
| Accurate 3100 | <<locked>> | 86% | 33,460 psi | 51% | 2470 fps | 95% |
| Accurate 4064 | <<locked>> | 80% | 48,892 psi | 75% | 2710 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 37,260 psi | 57% | 2575 fps | 98.1% |
| Accurate MAGPRO | <<locked>> | 98% | 52,214 psi | 80% | 2936 fps | 95.2% |
| ADI AR 2206H | <<locked>> | 80% | 54,302 psi | 84% | 2831 fps | 100% |
| ADI AR 2208 | <<locked>> | 80% | 46,021 psi | 71% | 2684 fps | 99.8% |
| ADI AR 2209 | <<locked>> | 90% | 43,990 psi | 68% | 2723 fps | 95.5% |
| ADI AR 2213 | <<locked>> | 96% | 47,950 psi | 74% | 2828 fps | 95% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 50,836 psi | 78% | 2897 fps | 100% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 46,659 psi | 72% | 2710 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 49,777 psi | 77% | 2779 fps | 100% |
| Alliant Reloder-16 | 48.4 gr | 80% | 36,347 psi | 56% | 2585 fps | 98.1% |
| Alliant Reloder-17 | <<locked>> | 80% | 41,075 psi | 63% | 2710 fps | 99.9% |
| Alliant Reloder-19 | <<locked>> | 90% | 43,584 psi | 67% | 2717 fps | 95.5% |
| Alliant Reloder-22 | <<locked>> | 94% | 43,845 psi | 67% | 2766 fps | 95.8% |
| Alliant Reloder-23 | <<locked>> | 80% | 26,629 psi | 41% | 2336 fps | 95.6% |
| Alliant Reloder-25 | <<locked>> | 92% | 34,156 psi | 53% | 2569 fps | 95.8% |
| Alliant Reloder-26 | 56.1 gr | 84% | 32,619 psi | 50% | 2569 fps | 96.1% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 54,201 psi | 83% | 2851 fps | 100% |
| Bofors RP15 | <<locked>> | 96% | 43,178 psi | 66% | 2753 fps | 95.4% |
| Bofors RP3 | <<locked>> | 80% | 46,876 psi | 72% | 2720 fps | 100% |
| Bofors RP5 | <<locked>> | 94% | 43,845 psi | 67% | 2766 fps | 95.8% |
| Bofors RP7 | <<locked>> | 80% | 41,365 psi | 64% | 2592 fps | 96% |
| Hodgdon H380 | <<locked>> | 80% | 47,369 psi | 73% | 2733 fps | 99.4% |
| Hodgdon H414 | <<locked>> | 80% | 39,218 psi | 60% | 2621 fps | 96% |
| Hodgdon H4350 | <<locked>> | 80% | 42,061 psi | 65% | 2641 fps | 95.4% |
| Hodgdon H4831 | <<locked>> | 96% | 51,111 psi | 79% | 2831 fps | 95.3% |
| Hodgdon H4831 SC | <<locked>> | 96% | 50,314 psi | 77% | 2815 fps | 95.1% |
| Hodgdon H4895 | <<locked>> | 80% | 54,897 psi | 84% | 2841 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 33,924 psi | 52% | 2480 fps | 98.7% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 51,561 psi | 79% | 2825 fps | 100% |
| Hodgdon Superformance | <<locked>> | 80% | 38,116 psi | 59% | 2628 fps | 95.1% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,137 psi | 42% | 1585 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 52,373 psi | 81% | 2789 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 48,414 psi | 74% | 2717 fps | 99.9% |
| IMR 4166 Enduron | <<locked>> | 80% | 50,792 psi | 78% | 2746 fps | 98.6% |
| IMR 4350 | <<locked>> | 82% | 39,320 psi | 60% | 2569 fps | 95.4% |
| IMR 4451 Enduron | <<locked>> | 80% | 42,714 psi | 66% | 2621 fps | 96.8% |
| IMR 4831 | <<locked>> | 80% | 35,868 psi | 55% | 2530 fps | 97.7% |
| IMR 4895 | <<locked>> | 80% | 51,068 psi | 79% | 2808 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 94% | 49,966 psi | 77% | 2776 fps | 95.2% |
| IMR 7828 SSC | <<locked>> | 98% | 48,689 psi | 75% | 2854 fps | 95.4% |
| Lovex D073.6 | <<locked>> | 80% | 54,636 psi | 84% | 2805 fps | 100% |
| Lovex S060 | <<locked>> | 80% | 52,997 psi | 82% | 2756 fps | 100% |
| Lovex S062 | <<locked>> | 80% | 48,631 psi | 75% | 2717 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 40,248 psi | 62% | 2572 fps | 97.6% |
| Lovex S070 | <<locked>> | 80% | 38,421 psi | 59% | 2549 fps | 95.9% |
| Lovex S071 | <<locked>> | 92% | 34,577 psi | 53% | 2500 fps | 95.5% |
| Norma 201 | <<locked>> | 80% | 53,026 psi | 82% | 2776 fps | 100% |
| Norma 202 | <<locked>> | 80% | 53,766 psi | 83% | 2772 fps | 100% |
| Norma 203B | <<locked>> | 80% | 49,139 psi | 76% | 2766 fps | 100% |
| Norma 204 | <<locked>> | 86% | 44,454 psi | 68% | 2713 fps | 95.5% |
| Norma MRP | <<locked>> | 88% | 37,550 psi | 58% | 2661 fps | 95.2% |
| Norma URP | <<locked>> | 80% | 36,941 psi | 57% | 2566 fps | 97.9% |
| Ramshot Big Game | <<locked>> | 80% | 49,356 psi | 76% | 2785 fps | 100% |
| Ramshot Grand | <<locked>> | 98% | 48,849 psi | 75% | 2867 fps | 95.8% |
| Ramshot Hunter | <<locked>> | 80% | 35,882 psi | 55% | 2552 fps | 95.8% |
| Ramshot Magnum | <<locked>> | 96% | 40,393 psi | 62% | 2677 fps | 95.3% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,789 psi | 43% | 1627 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 47,311 psi | 73% | 2713 fps | 98.5% |
| ReloadSwiss RS 52 | <<locked>> | 80% | 53,824 psi | 83% | 2897 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 43,627 psi | 67% | 2762 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 37,014 psi | 57% | 2592 fps | 97.7% |
| ReloadSwiss RS 70 | 52.9 gr | 80% | 35,868 psi | 55% | 2592 fps | 96.9% |
| ReloadSwiss RS 76 | <<locked>> | 98% | 40,118 psi | 62% | 2753 fps | 96.1% |
| Rottweil R 902 | <<locked>> | 80% | 50,546 psi | 78% | 2730 fps | 100% |
| Rottweil R 903 | <<locked>> | 80% | 44,077 psi | 68% | 2667 fps | 100% |
| Rottweil R 904 | <<locked>> | 92% | 48,515 psi | 75% | 2759 fps | 95.5% |
| Rottweil R 905 | <<locked>> | 90% | 42,685 psi | 66% | 2700 fps | 95.5% |
| Rottweil R 907 | <<locked>> | 80% | 41,365 psi | 64% | 2592 fps | 96% |
| Shooters World Long Rifle | <<locked>> | 80% | 40,248 psi | 62% | 2572 fps | 97.6% |
| Shooters World Match Rifle | <<locked>> | 80% | 54,636 psi | 84% | 2805 fps | 100% |
| Shooters World Precision | <<locked>> | 80% | 48,631 psi | 75% | 2717 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 38,421 psi | 59% | 2549 fps | 95.9% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 45,266 psi | 70% | 2720 fps | 99.9% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 52,707 psi | 81% | 2802 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 53,809 psi | 83% | 2707 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 45,527 psi | 70% | 2575 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 39,407 psi | 61% | 2516 fps | 96.1% |
| SNPE Vectan Tubal 8000 | <<locked>> | 90% | 42,293 psi | 65% | 2694 fps | 95.3% |
| Somchem S335 | <<locked>> | 80% | 53,563 psi | 82% | 2707 fps | 100% |
| Somchem S355 | <<locked>> | 80% | 44,483 psi | 68% | 2664 fps | 100% |
| Somchem S361 | <<locked>> | 92% | 49,995 psi | 77% | 2753 fps | 95% |
| Somchem S365 | <<locked>> | 80% | 33,489 psi | 52% | 2526 fps | 99.5% |
| Somchem S385 | <<locked>> | 88% | 40,466 psi | 62% | 2625 fps | 95.7% |
| Vihtavuori N133 | <<locked>> | 80% | 54,389 psi | 84% | 2690 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 50,850 psi | 78% | 2694 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 50,836 psi | 78% | 2703 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 42,395 psi | 65% | 2595 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 38,479 psi | 59% | 2572 fps | 98.2% |
| Vihtavuori N165 | <<locked>> | 92% | 39,813 psi | 61% | 2602 fps | 95% |
| Vihtavuori N540 | <<locked>> | 80% | 49,327 psi | 76% | 2700 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 37,985 psi | 58% | 2572 fps | 97.9% |
| Vihtavuori N555 | <<locked>> | 80% | 29,240 psi | 45% | 2411 fps | 95.8% |
| Vihtavuori N560 | <<locked>> | 96% | 49,937 psi | 77% | 2894 fps | 95.4% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 37,623 psi | 58% | 2543 fps | 99.6% |
| Winchester 760 | <<locked>> | 80% | 39,218 psi | 60% | 2621 fps | 96% |
| Winchester StaBALL HD | <<locked>> | 82% | 25,121 psi | 39% | 2359 fps | 95.1% |
| Winchester StaBALL Match | <<locked>> | 80% | 52,808 psi | 81% | 2812 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 92% | 42,670 psi | 66% | 2664 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 109 powders for .280 Ackley Improved loaded with the .284 | 150gr | Norma FMJ SemiP. Alliant Reloder-26 delivers the highest muzzle velocity at 3,081 fps; across all powders the maximum-charge window runs from 1,775 fps to 3,081 fps. Accurate 3100 gives the best case fill at 100 %, and 109 of the 109 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (448 MPa), the top charges use 54–90 %, leaving at least 10 % headroom. The 150.0 gr projectile in 0.284" calls for a 1:12.0 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, Alliant Reloder-16 rank at the top here: for .280 Ackley Improved with the .284 | 150gr | Norma FMJ SemiP they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, ADI AR 2217, ADI AR 2225, Baschieri & Pellagri 109 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.