Load Specifications
Load data in caliber .280 Ackley Improved with .285 | 139gr | Prvi Partizan SP 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-16 and Alliant Reloder-26.
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>> | 84% | 57,783 psi | 89% | 2904 fps | 100% |
| Accurate 2700 | <<locked>> | 88% | 56,869 psi | 87% | 2930 fps | 98.5% |
| Accurate 3100ᴾ | <<locked>> | 100% | 53,113 psi | 82% | 2956 fps | 99.2% |
| Accurate 4064 | <<locked>> | 86% | 58,146 psi | 89% | 2959 fps | 100% |
| Accurate 4350 | <<locked>> | 92% | 55,317 psi | 85% | 3012 fps | 100% |
| ADI AR 2206H | <<locked>> | 82% | 56,971 psi | 88% | 2989 fps | 100% |
| ADI AR 2208 | <<locked>> | 88% | 58,131 psi | 89% | 2992 fps | 100% |
| ADI AR 2209 | <<locked>> | 98% | 56,463 psi | 87% | 3058 fps | 97.8% |
| ADI AR 2213ᴾ | <<locked>> | 100% | 53,983 psi | 83% | 3041 fps | 96% |
| Alliant Power Pro 2000-MR | <<locked>> | 84% | 57,928 psi | 89% | 3127 fps | 100% |
| Alliant Reloder- TS 15.5 | <<locked>> | 86% | 55,506 psi | 85% | 2966 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 84% | 55,724 psi | 86% | 2986 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 94% | 55,970 psi | 86% | 3071 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 90% | 57,551 psi | 89% | 3100 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 98% | 55,593 psi | 86% | 3041 fps | 97.7% |
| Alliant Reloder-22ᴾ | <<locked>> | 100% | 52,779 psi | 81% | 3038 fps | 97.4% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 49,835 psi | 77% | 2976 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 43,352 psi | 67% | 2884 fps | 98.3% |
| Alliant Reloder-26ᴾ | <<locked>> | 100% | 57,653 psi | 89% | 3179 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 82% | 57,217 psi | 88% | 3009 fps | 100% |
| Bofors RP15ᴾ | <<locked>> | 100% | 48,385 psi | 74% | 2953 fps | 96.2% |
| Bofors RP3 | <<locked>> | 86% | 56,347 psi | 87% | 2982 fps | 100% |
| Bofors RP5ᴾ | <<locked>> | 100% | 52,779 psi | 81% | 3038 fps | 97.4% |
| Bofors RP7 | <<locked>> | 90% | 55,709 psi | 86% | 2959 fps | 98.5% |
| Hodgdon H380 | <<locked>> | 86% | 56,782 psi | 87% | 2999 fps | 99.9% |
| Hodgdon H414 | <<locked>> | 88% | 55,143 psi | 85% | 3028 fps | 98.9% |
| Hodgdon H4350 | <<locked>> | 92% | 55,550 psi | 85% | 2995 fps | 97.9% |
| Hodgdon H4831 SCᴾ | <<locked>> | 100% | 56,710 psi | 87% | 3028 fps | 95.9% |
| Hodgdon H4895 | <<locked>> | 82% | 57,653 psi | 89% | 2995 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 96% | 56,434 psi | 87% | 2992 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 86% | 58,291 psi | 90% | 3038 fps | 100% |
| Hodgdon Superformance | <<locked>> | 92% | 58,146 psi | 89% | 3107 fps | 99.1% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,390 psi | 56% | 1860 fps | 100% |
| Hodgdon VARGET | <<locked>> | 86% | 57,783 psi | 89% | 2986 fps | 100% |
| IMR 3031 | <<locked>> | 84% | 57,188 psi | 88% | 2956 fps | 100% |
| IMR 4064 | <<locked>> | 88% | 56,913 psi | 88% | 2966 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 88% | 55,927 psi | 86% | 2943 fps | 98.9% |
| IMR 4350 | <<locked>> | 94% | 56,768 psi | 87% | 2995 fps | 98.7% |
| IMR 4451 Enduron | <<locked>> | 90% | 57,406 psi | 88% | 2989 fps | 99% |
| IMR 4831 | <<locked>> | 98% | 56,565 psi | 87% | 3018 fps | 100% |
| IMR 4895 | <<locked>> | 84% | 57,145 psi | 88% | 3015 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 98% | 55,927 psi | 86% | 2979 fps | 96% |
| IMR 7828 SSCᴾ | <<locked>> | 100% | 55,608 psi | 86% | 3084 fps | 96.5% |
| Lovex D073.6 | <<locked>> | 82% | 57,493 psi | 88% | 2959 fps | 100% |
| Lovex S060 | <<locked>> | 82% | 55,825 psi | 86% | 2910 fps | 100% |
| Lovex S062 | <<locked>> | 86% | 57,914 psi | 89% | 2969 fps | 100% |
| Lovex S065 | <<locked>> | 92% | 57,435 psi | 88% | 2986 fps | 99.7% |
| Lovex S070 | <<locked>> | 94% | 58,755 psi | 90% | 3028 fps | 99.4% |
| Lovex S071ᴾ | <<locked>> | 100% | 44,150 psi | 68% | 2799 fps | 97.7% |
| Norma 201 | <<locked>> | 82% | 55,825 psi | 86% | 2930 fps | 100% |
| Norma 202 | <<locked>> | 82% | 56,289 psi | 87% | 2927 fps | 100% |
| Norma 203B | <<locked>> | 86% | 58,595 psi | 90% | 3025 fps | 100% |
| Norma 204 | <<locked>> | 94% | 57,682 psi | 89% | 3051 fps | 97.9% |
| Norma MRPᴾ | <<locked>> | 100% | 56,144 psi | 86% | 3127 fps | 99.1% |
| Norma URP | <<locked>> | 94% | 57,493 psi | 88% | 3051 fps | 100% |
| Ramshot Big Game | <<locked>> | 84% | 55,912 psi | 86% | 2999 fps | 100% |
| Ramshot Grand | <<locked>> | 98% | 55,274 psi | 85% | 3087 fps | 96.8% |
| Ramshot Hunter | <<locked>> | 94% | 56,449 psi | 87% | 3054 fps | 99.5% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 51,996 psi | 80% | 2999 fps | 97.8% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 36,999 psi | 57% | 1906 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 86% | 56,840 psi | 87% | 2982 fps | 99.4% |
| ReloadSwiss RS 52 | <<locked>> | 82% | 56,623 psi | 87% | 3054 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 88% | 56,927 psi | 88% | 3091 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 92% | 55,259 psi | 85% | 3038 fps | 99.9% |
| ReloadSwiss RS 70 | <<locked>> | 94% | 57,653 psi | 89% | 3127 fps | 100% |
| Rottweil R 902 | <<locked>> | 84% | 56,492 psi | 87% | 2930 fps | 100% |
| Rottweil R 903 | <<locked>> | 88% | 56,463 psi | 87% | 2979 fps | 100% |
| Rottweil R 904 | <<locked>> | 98% | 58,088 psi | 89% | 3025 fps | 97% |
| Rottweil R 905ᴾ | <<locked>> | 100% | 58,566 psi | 90% | 3084 fps | 98.3% |
| Rottweil R 907 | <<locked>> | 90% | 55,709 psi | 86% | 2959 fps | 98.5% |
| Shooters World Long Rifle | <<locked>> | 92% | 57,435 psi | 88% | 2986 fps | 99.7% |
| Shooters World Match Rifle | <<locked>> | 82% | 57,493 psi | 88% | 2959 fps | 100% |
| Shooters World Precision | <<locked>> | 86% | 57,914 psi | 89% | 2969 fps | 100% |
| Shooters World SW4350 | <<locked>> | 94% | 58,755 psi | 90% | 3028 fps | 99.4% |
| SNPE Vectan SP 11 | <<locked>> | 88% | 58,189 psi | 90% | 3041 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 82% | 58,479 psi | 90% | 2995 fps | 99.9% |
| SNPE Vectan SP 9 | <<locked>> | 82% | 55,376 psi | 85% | 2956 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 82% | 56,463 psi | 87% | 2858 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 88% | 57,421 psi | 88% | 2861 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 92% | 57,246 psi | 88% | 2940 fps | 99.1% |
| SNPE Vectan Tubal 8000ᴾ | <<locked>> | 100% | 58,059 psi | 89% | 3077 fps | 98.2% |
| Somchem S335 | <<locked>> | 82% | 56,304 psi | 87% | 2858 fps | 100% |
| Somchem S341 | <<locked>> | 82% | 58,204 psi | 90% | 2982 fps | 100% |
| Somchem S355 | <<locked>> | 88% | 56,449 psi | 87% | 2972 fps | 100% |
| Somchem S361 | <<locked>> | 96% | 56,478 psi | 87% | 2963 fps | 95.9% |
| Somchem S365 | <<locked>> | 96% | 57,043 psi | 88% | 3058 fps | 100% |
| Somchem S385 | <<locked>> | 98% | 55,550 psi | 85% | 3002 fps | 98.5% |
| Unknown powder | <<locked>> | 92% | 58,291 psi | 90% | 3058 fps | 99.9% |
| Vihtavuori N133 | <<locked>> | 82% | 56,942 psi | 88% | 2841 fps | 100% |
| Vihtavuori N135 | <<locked>> | 84% | 56,536 psi | 87% | 2887 fps | 100% |
| Vihtavuori N140 | <<locked>> | 84% | 56,985 psi | 88% | 2904 fps | 100% |
| Vihtavuori N150 | <<locked>> | 90% | 57,827 psi | 89% | 2946 fps | 100% |
| Vihtavuori N160 | <<locked>> | 92% | 56,144 psi | 86% | 2992 fps | 100% |
| Vihtavuori N165ᴾ | <<locked>> | 100% | 51,242 psi | 79% | 2917 fps | 97.4% |
| Vihtavuori N540 | <<locked>> | 86% | 58,769 psi | 90% | 2949 fps | 100% |
| Vihtavuori N550 | <<locked>> | 92% | 55,274 psi | 85% | 2995 fps | 99.9% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 55,753 psi | 86% | 3054 fps | 100% |
| Vihtavuori N560ᴾ | <<locked>> | 100% | 56,449 psi | 87% | 3114 fps | 96.3% |
| Winchester 6.5 StaBALL | <<locked>> | 92% | 55,767 psi | 86% | 2956 fps | 100% |
| Winchester 760 | <<locked>> | 88% | 55,143 psi | 85% | 3028 fps | 98.9% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 45,034 psi | 69% | 3028 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 98% | 57,914 psi | 89% | 3028 fps | 98% |
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% | 50,865 psi | 78% | 2805 fps | 100% |
| Accurate 2700 | <<locked>> | 80% | 43,816 psi | 67% | 2700 fps | 95.9% |
| Accurate 3100 | <<locked>> | 88% | 35,201 psi | 54% | 2605 fps | 95% |
| Accurate 4064 | <<locked>> | 80% | 48,153 psi | 74% | 2808 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 36,550 psi | 56% | 2654 fps | 97.3% |
| ADI AR 2206H | <<locked>> | 80% | 53,490 psi | 82% | 2933 fps | 100% |
| ADI AR 2208 | <<locked>> | 80% | 45,513 psi | 70% | 2779 fps | 99.5% |
| ADI AR 2209 | <<locked>> | 92% | 46,325 psi | 71% | 2871 fps | 95.5% |
| ADI AR 2213 | <<locked>> | 98% | 50,531 psi | 78% | 2976 fps | 95% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 50,140 psi | 77% | 2999 fps | 99.9% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 45,992 psi | 71% | 2805 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 49,037 psi | 75% | 2874 fps | 99.8% |
| Alliant Reloder-16 | 50.6 gr | 80% | 35,795 psi | 55% | 2667 fps | 97.4% |
| Alliant Reloder-17 | <<locked>> | 80% | 40,553 psi | 62% | 2799 fps | 99.6% |
| Alliant Reloder-19 | <<locked>> | 92% | 45,788 psi | 70% | 2861 fps | 95.5% |
| Alliant Reloder-22 | <<locked>> | 96% | 46,224 psi | 71% | 2917 fps | 95.8% |
| Alliant Reloder-23 | <<locked>> | 82% | 27,978 psi | 43% | 2464 fps | 95.5% |
| Alliant Reloder-25 | <<locked>> | 94% | 35,926 psi | 55% | 2703 fps | 95.8% |
| Alliant Reloder-26 | 60 gr | 86% | 34,403 psi | 53% | 2707 fps | 96.1% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 53,461 psi | 82% | 2949 fps | 99.9% |
| Bofors RP15 | <<locked>> | 98% | 45,310 psi | 70% | 2894 fps | 95.3% |
| Bofors RP3 | <<locked>> | 80% | 46,253 psi | 71% | 2818 fps | 100% |
| Bofors RP5 | <<locked>> | 96% | 46,224 psi | 71% | 2917 fps | 95.8% |
| Bofors RP7 | <<locked>> | 80% | 40,814 psi | 63% | 2680 fps | 95.1% |
| Hodgdon H380 | <<locked>> | 80% | 46,499 psi | 72% | 2822 fps | 99% |
| Hodgdon H414 | <<locked>> | 80% | 41,887 psi | 64% | 2779 fps | 96.2% |
| Hodgdon H4350 | <<locked>> | 84% | 43,221 psi | 66% | 2766 fps | 95% |
| Hodgdon H4831 SC | <<locked>> | 98% | 53,026 psi | 82% | 2966 fps | 95.1% |
| Hodgdon H4895 | <<locked>> | 80% | 54,070 psi | 83% | 2943 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 33,214 psi | 51% | 2559 fps | 98% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 47,776 psi | 74% | 2871 fps | 100% |
| Hodgdon Superformance | <<locked>> | 82% | 40,350 psi | 62% | 2772 fps | 95.1% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,137 psi | 42% | 1663 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 47,921 psi | 74% | 2825 fps | 100% |
| IMR 3031 | <<locked>> | 80% | 50,227 psi | 77% | 2854 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 44,585 psi | 69% | 2756 fps | 99.5% |
| IMR 4166 Enduron | <<locked>> | 80% | 43,874 psi | 67% | 2720 fps | 96.7% |
| IMR 4350 | <<locked>> | 84% | 41,365 psi | 64% | 2713 fps | 95.3% |
| IMR 4451 Enduron | <<locked>> | 80% | 42,163 psi | 65% | 2710 fps | 96.1% |
| IMR 4831 | <<locked>> | 80% | 31,923 psi | 49% | 2523 fps | 95.7% |
| IMR 4895 | <<locked>> | 80% | 50,256 psi | 77% | 2904 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 96% | 52,533 psi | 81% | 2923 fps | 95.2% |
| IMR 7828 SSC | <<locked>> | 98% | 51,750 psi | 80% | 3015 fps | 95.5% |
| Lovex D073.6 | <<locked>> | 80% | 53,882 psi | 83% | 2910 fps | 100% |
| Lovex S060 | <<locked>> | 80% | 52,460 psi | 81% | 2858 fps | 100% |
| Lovex S062 | <<locked>> | 80% | 48,066 psi | 74% | 2815 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 39,697 psi | 61% | 2661 fps | 96.9% |
| Lovex S070 | <<locked>> | 80% | 38,014 psi | 58% | 2638 fps | 95.1% |
| Lovex S071 | <<locked>> | 94% | 36,347 psi | 56% | 2631 fps | 95.4% |
| Norma 201 | <<locked>> | 80% | 52,388 psi | 81% | 2877 fps | 100% |
| Norma 202 | <<locked>> | 80% | 53,055 psi | 82% | 2877 fps | 100% |
| Norma 203B | <<locked>> | 80% | 48,399 psi | 74% | 2861 fps | 99.9% |
| Norma 204 | <<locked>> | 88% | 47,094 psi | 72% | 2864 fps | 95.6% |
| Norma MRP | <<locked>> | 90% | 39,566 psi | 61% | 2799 fps | 95.1% |
| Norma URP | <<locked>> | 80% | 36,506 psi | 56% | 2654 fps | 97.1% |
| Ramshot Big Game | <<locked>> | 80% | 48,718 psi | 75% | 2884 fps | 99.9% |
| Ramshot Grand | <<locked>> | 96% | 51,256 psi | 79% | 3015 fps | 95.8% |
| Ramshot Hunter | <<locked>> | 82% | 37,695 psi | 58% | 2694 fps | 95.7% |
| Ramshot Magnum | <<locked>> | 96% | 44,657 psi | 69% | 2861 fps | 96% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,543 psi | 42% | 1699 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 46,644 psi | 72% | 2805 fps | 97.9% |
| ReloadSwiss RS 52 | <<locked>> | 80% | 52,982 psi | 82% | 2999 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 43,091 psi | 66% | 2861 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 36,289 psi | 56% | 2671 fps | 96.8% |
| ReloadSwiss RS 70 | 55.3 gr | 80% | 35,375 psi | 54% | 2674 fps | 96% |
| Rottweil R 902 | <<locked>> | 80% | 49,995 psi | 77% | 2831 fps | 100% |
| Rottweil R 903 | <<locked>> | 80% | 43,598 psi | 67% | 2762 fps | 99.8% |
| Rottweil R 904 | <<locked>> | 94% | 50,995 psi | 78% | 2904 fps | 95.5% |
| Rottweil R 905 | <<locked>> | 92% | 44,759 psi | 69% | 2841 fps | 95.4% |
| Rottweil R 907 | <<locked>> | 80% | 40,814 psi | 63% | 2680 fps | 95.1% |
| Shooters World Long Rifle | <<locked>> | 80% | 39,697 psi | 61% | 2661 fps | 96.9% |
| Shooters World Match Rifle | <<locked>> | 80% | 53,882 psi | 83% | 2910 fps | 100% |
| Shooters World Precision | <<locked>> | 80% | 48,066 psi | 74% | 2815 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 38,014 psi | 58% | 2638 fps | 95.1% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 44,570 psi | 69% | 2812 fps | 99.6% |
| SNPE Vectan SP 7 | <<locked>> | 80% | 54,607 psi | 84% | 2936 fps | 99.8% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 52,011 psi | 80% | 2904 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 53,156 psi | 82% | 2812 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 44,875 psi | 69% | 2674 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 38,812 psi | 60% | 2598 fps | 95.2% |
| SNPE Vectan Tubal 8000 | <<locked>> | 92% | 44,338 psi | 68% | 2835 fps | 95.2% |
| Somchem S335 | <<locked>> | 80% | 52,910 psi | 81% | 2808 fps | 100% |
| Somchem S341 | <<locked>> | 80% | 54,404 psi | 84% | 2923 fps | 100% |
| Somchem S355 | <<locked>> | 80% | 43,888 psi | 68% | 2759 fps | 99.8% |
| Somchem S361 | <<locked>> | 94% | 52,750 psi | 81% | 2897 fps | 95% |
| Somchem S365 | <<locked>> | 80% | 32,851 psi | 51% | 2605 fps | 99% |
| Somchem S385 | <<locked>> | 90% | 42,598 psi | 66% | 2766 fps | 95.7% |
| Unknown powder | <<locked>> | 80% | 39,247 psi | 60% | 2710 fps | 97.3% |
| Vihtavuori N133 | <<locked>> | 80% | 53,664 psi | 83% | 2795 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 50,053 psi | 77% | 2795 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 50,415 psi | 78% | 2808 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 41,974 psi | 65% | 2690 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 37,797 psi | 58% | 2654 fps | 97.5% |
| Vihtavuori N165 | <<locked>> | 94% | 41,945 psi | 65% | 2740 fps | 95% |
| Vihtavuori N540 | <<locked>> | 80% | 48,472 psi | 75% | 2795 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 37,246 psi | 57% | 2651 fps | 97.1% |
| Vihtavuori N555 | <<locked>> | 82% | 30,748 psi | 47% | 2543 fps | 95.7% |
| Vihtavuori N560 | <<locked>> | 98% | 52,866 psi | 81% | 3051 fps | 95.4% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 37,115 psi | 57% | 2625 fps | 99.2% |
| Winchester 760 | <<locked>> | 80% | 41,887 psi | 64% | 2779 fps | 96.2% |
| Winchester StaBALL HD | <<locked>> | 84% | 26,339 psi | 41% | 2484 fps | 95% |
| Winchester Supreme 780 | <<locked>> | 92% | 46,398 psi | 71% | 2835 fps | 95.6% |
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 111 powders for .280 Ackley Improved loaded with the .285 | 139gr | Prvi Partizan SP. Alliant Reloder-26 delivers the highest muzzle velocity at 3,179 fps; across all powders the maximum-charge window runs from 1,860 fps to 3,179 fps. Accurate 3100 gives the best case fill at 100 %, and 111 of the 111 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 139.0 gr projectile in 0.285" calls for a 1:16.0 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-16, Alliant Reloder-26 rank at the top here: for .280 Ackley Improved with the .285 | 139gr | Prvi Partizan SP they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, Accurate MAGPRO, 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.