Load Specifications
Load data in caliber .280 Ackley Improved with .284 | 140gr | Sierra Pro-Hunter 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, Hodgdon Superformance and Alliant Reloder-17.
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% | 56,260 psi | 87% | 2867 fps | 100% |
| Accurate 2700 | <<locked>> | 86% | 57,682 psi | 89% | 2930 fps | 98.4% |
| Accurate 3100ᴾ | <<locked>> | 100% | 50,995 psi | 78% | 2904 fps | 98.8% |
| Accurate 4064 | <<locked>> | 86% | 56,449 psi | 87% | 2920 fps | 100% |
| Accurate 4350 | <<locked>> | 94% | 57,246 psi | 88% | 3025 fps | 100% |
| ADI AR 2206H | <<locked>> | 82% | 55,390 psi | 85% | 2943 fps | 100% |
| ADI AR 2208 | <<locked>> | 88% | 56,710 psi | 87% | 2949 fps | 100% |
| ADI AR 2209ᴾ | <<locked>> | 100% | 58,247 psi | 90% | 3061 fps | 97.9% |
| ADI Benchmark 8208 | <<locked>> | 82% | 57,580 psi | 89% | 2940 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 84% | 55,782 psi | 86% | 3074 fps | 100% |
| Alliant Reloder- TS 15.5 | <<locked>> | 88% | 57,377 psi | 88% | 2972 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 86% | 57,812 psi | 89% | 2999 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 96% | 57,551 psi | 89% | 3077 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 90% | 55,347 psi | 85% | 3051 fps | 100% |
| Alliant Reloder-19ᴾ | <<locked>> | 100% | 57,188 psi | 88% | 3048 fps | 97.9% |
| Alliant Reloder-22ᴾ | <<locked>> | 100% | 50,763 psi | 78% | 2982 fps | 96.8% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 48,008 psi | 74% | 2930 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 41,916 psi | 64% | 2835 fps | 97.8% |
| Alliant Reloder-26ᴾ | <<locked>> | 100% | 54,940 psi | 85% | 3123 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 82% | 55,564 psi | 85% | 2963 fps | 100% |
| Bofors RP3 | <<locked>> | 88% | 58,378 psi | 90% | 2992 fps | 100% |
| Bofors RP5ᴾ | <<locked>> | 100% | 50,763 psi | 78% | 2982 fps | 96.8% |
| Bofors RP7 | <<locked>> | 92% | 57,566 psi | 89% | 2969 fps | 98.6% |
| Hodgdon BL-C2 | <<locked>> | 82% | 57,812 psi | 89% | 2976 fps | 100% |
| Hodgdon H380 | <<locked>> | 86% | 55,100 psi | 85% | 2953 fps | 99.8% |
| Hodgdon H414 | <<locked>> | 92% | 55,637 psi | 86% | 3018 fps | 98.9% |
| Hodgdon H4350 | <<locked>> | 90% | 55,695 psi | 86% | 2979 fps | 97.8% |
| Hodgdon H4895 | <<locked>> | 82% | 55,985 psi | 86% | 2953 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 98% | 58,102 psi | 89% | 2999 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 84% | 56,217 psi | 86% | 2989 fps | 100% |
| Hodgdon Superformance | <<locked>> | 92% | 56,014 psi | 86% | 3058 fps | 98.7% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,201 psi | 56% | 1837 fps | 100% |
| Hodgdon VARGET | <<locked>> | 84% | 57,130 psi | 88% | 2956 fps | 100% |
| IMR 3031 | <<locked>> | 82% | 56,666 psi | 87% | 2933 fps | 100% |
| IMR 4064 | <<locked>> | 86% | 56,246 psi | 87% | 2933 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 84% | 55,390 psi | 85% | 2913 fps | 98.7% |
| IMR 4350 | <<locked>> | 96% | 58,552 psi | 90% | 3002 fps | 98.8% |
| IMR 4451 Enduron | <<locked>> | 90% | 55,956 psi | 86% | 2946 fps | 98.7% |
| IMR 4831 | <<locked>> | 96% | 57,363 psi | 88% | 3009 fps | 100% |
| IMR 4895 | <<locked>> | 84% | 55,564 psi | 85% | 2972 fps | 100% |
| IMR 4955 Enduronᴾ | <<locked>> | 100% | 57,667 psi | 89% | 2986 fps | 96.1% |
| IMR 8208 XBR | <<locked>> | 82% | 57,580 psi | 89% | 2940 fps | 100% |
| Lovex D073.6 | <<locked>> | 82% | 55,854 psi | 86% | 2920 fps | 100% |
| Lovex S060 | <<locked>> | 84% | 57,914 psi | 89% | 2920 fps | 100% |
| Lovex S062 | <<locked>> | 86% | 56,347 psi | 87% | 2927 fps | 100% |
| Lovex S065 | <<locked>> | 92% | 55,927 psi | 86% | 2943 fps | 99.5% |
| Lovex S070 | <<locked>> | 94% | 57,043 psi | 88% | 2982 fps | 99.1% |
| Lovex S071ᴾ | <<locked>> | 100% | 42,322 psi | 65% | 2746 fps | 97.2% |
| Norma 201 | <<locked>> | 84% | 57,885 psi | 89% | 2940 fps | 100% |
| Norma 202 | <<locked>> | 84% | 58,320 psi | 90% | 2933 fps | 100% |
| Norma 203B | <<locked>> | 86% | 57,058 psi | 88% | 2986 fps | 100% |
| Norma 204 | <<locked>> | 94% | 55,811 psi | 86% | 2999 fps | 97.4% |
| Norma MRPᴾ | <<locked>> | 100% | 53,766 psi | 83% | 3071 fps | 98.6% |
| Norma URP | <<locked>> | 94% | 55,622 psi | 86% | 3005 fps | 99.9% |
| Ramshot Big Game | <<locked>> | 86% | 58,001 psi | 89% | 3012 fps | 100% |
| Ramshot Hunter | <<locked>> | 96% | 58,305 psi | 90% | 3061 fps | 99.6% |
| Ramshot TAC | <<locked>> | 82% | 58,001 psi | 89% | 2972 fps | 99.8% |
| Ramshot Wild Boar | <<locked>> | 82% | 58,146 psi | 89% | 2986 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 36,811 psi | 57% | 1880 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 88% | 58,755 psi | 90% | 2992 fps | 99.5% |
| ReloadSwiss RS 52 | <<locked>> | 82% | 54,926 psi | 85% | 3012 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 88% | 54,911 psi | 84% | 3048 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 94% | 57,000 psi | 88% | 3048 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 94% | 55,521 psi | 85% | 3071 fps | 99.9% |
| Rottweil R 901 | <<locked>> | 82% | 58,523 psi | 90% | 2913 fps | 100% |
| Rottweil R 902 | <<locked>> | 86% | 58,305 psi | 90% | 2940 fps | 100% |
| Rottweil R 903 | <<locked>> | 90% | 58,175 psi | 89% | 2982 fps | 100% |
| Rottweil R 904 | <<locked>> | 98% | 56,260 psi | 87% | 2972 fps | 96.5% |
| Rottweil R 905ᴾ | <<locked>> | 100% | 56,347 psi | 87% | 3031 fps | 97.8% |
| Rottweil R 907 | <<locked>> | 92% | 57,566 psi | 89% | 2969 fps | 98.6% |
| Shooters World Long Rifle | <<locked>> | 92% | 55,927 psi | 86% | 2943 fps | 99.5% |
| Shooters World Match Rifle | <<locked>> | 82% | 55,854 psi | 86% | 2920 fps | 100% |
| Shooters World Precision | <<locked>> | 86% | 56,347 psi | 87% | 2927 fps | 100% |
| Shooters World SW4350 | <<locked>> | 94% | 57,043 psi | 88% | 2982 fps | 99.1% |
| SNPE Vectan SP 11 | <<locked>> | 88% | 56,289 psi | 87% | 2995 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 82% | 56,826 psi | 87% | 2949 fps | 99.8% |
| SNPE Vectan SP 9 | <<locked>> | 84% | 57,479 psi | 88% | 2969 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 84% | 58,537 psi | 90% | 2867 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 88% | 55,912 psi | 86% | 2822 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 92% | 55,593 psi | 86% | 2890 fps | 98.7% |
| SNPE Vectan Tubal 8000ᴾ | <<locked>> | 100% | 55,854 psi | 86% | 3025 fps | 97.7% |
| Somchem S335 | <<locked>> | 84% | 58,378 psi | 90% | 2867 fps | 100% |
| Somchem S341 | <<locked>> | 82% | 56,594 psi | 87% | 2940 fps | 100% |
| Somchem S355 | <<locked>> | 90% | 58,131 psi | 89% | 2979 fps | 100% |
| Somchem S361 | <<locked>> | 98% | 58,421 psi | 90% | 2969 fps | 96% |
| Somchem S365 | <<locked>> | 98% | 58,407 psi | 90% | 3061 fps | 100% |
| Somchem S385ᴾ | <<locked>> | 100% | 57,232 psi | 88% | 3009 fps | 98.6% |
| Vihtavuori N133 | <<locked>> | 82% | 55,738 psi | 86% | 2805 fps | 100% |
| Vihtavuori N135 | <<locked>> | 86% | 58,552 psi | 90% | 2894 fps | 100% |
| Vihtavuori N140 | <<locked>> | 84% | 55,405 psi | 85% | 2864 fps | 100% |
| Vihtavuori N150 | <<locked>> | 90% | 55,927 psi | 86% | 2904 fps | 100% |
| Vihtavuori N160 | <<locked>> | 94% | 58,088 psi | 89% | 3002 fps | 100% |
| Vihtavuori N165ᴾ | <<locked>> | 100% | 49,284 psi | 76% | 2864 fps | 96.8% |
| Vihtavuori N530 | <<locked>> | 82% | 58,233 psi | 90% | 2940 fps | 100% |
| Vihtavuori N540 | <<locked>> | 86% | 57,159 psi | 88% | 2910 fps | 100% |
| Vihtavuori N550 | <<locked>> | 94% | 56,927 psi | 88% | 3005 fps | 99.9% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 53,621 psi | 82% | 3005 fps | 100% |
| Winchester 6.5 StaBALL | <<locked>> | 94% | 57,769 psi | 89% | 2969 fps | 100% |
| Winchester 760 | <<locked>> | 92% | 55,941 psi | 86% | 3022 fps | 98.9% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 43,294 psi | 67% | 2972 fps | 100% |
| Winchester StaBALL Match | <<locked>> | 84% | 57,870 psi | 89% | 2979 fps | 100% |
| Winchester Supreme 780ᴾ | <<locked>> | 100% | 53,548 psi | 82% | 2940 fps | 97% |
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% | 49,269 psi | 76% | 2766 fps | 100% |
| Accurate 2700 | <<locked>> | 80% | 47,398 psi | 73% | 2759 fps | 96.6% |
| Accurate 3100 | <<locked>> | 90% | 36,332 psi | 56% | 2618 fps | 95.3% |
| Accurate 4064 | <<locked>> | 80% | 46,673 psi | 72% | 2769 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 35,230 psi | 54% | 2612 fps | 96.7% |
| ADI AR 2206H | <<locked>> | 80% | 52,127 psi | 80% | 2890 fps | 100% |
| ADI AR 2208 | <<locked>> | 80% | 44,237 psi | 68% | 2736 fps | 99.2% |
| ADI AR 2209 | <<locked>> | 94% | 47,718 psi | 73% | 2881 fps | 95.7% |
| ADI Benchmark 8208 | <<locked>> | 80% | 54,230 psi | 83% | 2890 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 48,631 psi | 75% | 2949 fps | 99.8% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 44,657 psi | 69% | 2766 fps | 99.9% |
| Alliant Reloder-15 | <<locked>> | 80% | 47,688 psi | 73% | 2831 fps | 99.7% |
| Alliant Reloder-16 | <<locked>> | 80% | 34,679 psi | 53% | 2621 fps | 96.8% |
| Alliant Reloder-17 | 52.5 gr | 80% | 38,957 psi | 60% | 2749 fps | 99.3% |
| Alliant Reloder-19 | <<locked>> | 94% | 47,297 psi | 73% | 2874 fps | 95.7% |
| Alliant Reloder-22 | <<locked>> | 96% | 44,512 psi | 68% | 2864 fps | 95.1% |
| Alliant Reloder-23 | <<locked>> | 84% | 28,776 psi | 44% | 2477 fps | 95.9% |
| Alliant Reloder-25 | <<locked>> | 96% | 36,912 psi | 57% | 2713 fps | 96% |
| Alliant Reloder-26 | <<locked>> | 86% | 33,069 psi | 51% | 2654 fps | 95.2% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 51,837 psi | 80% | 2904 fps | 99.8% |
| Bofors RP3 | <<locked>> | 80% | 44,686 psi | 69% | 2772 fps | 99.9% |
| Bofors RP5 | <<locked>> | 96% | 44,512 psi | 68% | 2864 fps | 95.1% |
| Bofors RP7 | <<locked>> | 82% | 42,206 psi | 65% | 2690 fps | 95.4% |
| Hodgdon BL-C2 | <<locked>> | 80% | 54,157 psi | 83% | 2920 fps | 100% |
| Hodgdon H380 | <<locked>> | 80% | 45,266 psi | 70% | 2782 fps | 98.7% |
| Hodgdon H414 | <<locked>> | 82% | 39,900 psi | 61% | 2717 fps | 95.4% |
| Hodgdon H4350 | <<locked>> | 84% | 45,948 psi | 71% | 2802 fps | 95.7% |
| Hodgdon H4895 | <<locked>> | 80% | 52,707 psi | 81% | 2900 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 32,213 psi | 50% | 2520 fps | 97.5% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 49,182 psi | 76% | 2877 fps | 100% |
| Hodgdon Superformance | 58.3 gr | 84% | 41,843 psi | 64% | 2792 fps | 95.5% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,064 psi | 42% | 1644 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 50,299 psi | 77% | 2848 fps | 100% |
| IMR 3031 | <<locked>> | 80% | 53,156 psi | 82% | 2884 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 46,485 psi | 72% | 2772 fps | 99.6% |
| IMR 4166 Enduron | <<locked>> | 80% | 48,921 psi | 75% | 2802 fps | 97.7% |
| IMR 4350 | <<locked>> | 86% | 42,888 psi | 66% | 2726 fps | 95.6% |
| IMR 4451 Enduron | <<locked>> | 80% | 41,046 psi | 63% | 2667 fps | 95.6% |
| IMR 4831 | <<locked>> | 80% | 34,055 psi | 52% | 2566 fps | 96.4% |
| IMR 4895 | <<locked>> | 80% | 48,892 psi | 75% | 2861 fps | 99.9% |
| IMR 4955 Enduron | <<locked>> | 98% | 54,027 psi | 83% | 2927 fps | 95.3% |
| IMR 8208 XBR | <<locked>> | 80% | 54,230 psi | 83% | 2890 fps | 100% |
| Lovex D073.6 | <<locked>> | 80% | 52,214 psi | 80% | 2864 fps | 100% |
| Lovex S060 | <<locked>> | 80% | 51,126 psi | 79% | 2815 fps | 100% |
| Lovex S062 | <<locked>> | 80% | 46,673 psi | 72% | 2772 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 38,566 psi | 59% | 2615 fps | 96.4% |
| Lovex S070 | <<locked>> | 82% | 39,233 psi | 60% | 2648 fps | 95.4% |
| Lovex S071 | <<locked>> | 96% | 37,130 psi | 57% | 2638 fps | 95.6% |
| Norma 201 | <<locked>> | 80% | 50,952 psi | 78% | 2838 fps | 100% |
| Norma 202 | <<locked>> | 80% | 51,605 psi | 79% | 2835 fps | 100% |
| Norma 203B | <<locked>> | 80% | 47,036 psi | 72% | 2818 fps | 99.8% |
| Norma 204 | <<locked>> | 90% | 48,660 psi | 75% | 2877 fps | 95.8% |
| Norma MRP | <<locked>> | 92% | 40,814 psi | 63% | 2815 fps | 95.4% |
| Norma URP | <<locked>> | 80% | 35,288 psi | 54% | 2612 fps | 96.6% |
| Ramshot Big Game | <<locked>> | 80% | 47,253 psi | 73% | 2841 fps | 99.8% |
| Ramshot Hunter | <<locked>> | 82% | 36,463 psi | 56% | 2648 fps | 95.1% |
| Ramshot TAC | <<locked>> | 80% | 54,186 psi | 83% | 2910 fps | 99.5% |
| Ramshot Wild Boar | <<locked>> | 80% | 54,230 psi | 83% | 2927 fps | 100% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,485 psi | 42% | 1680 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 45,310 psi | 70% | 2759 fps | 97.5% |
| ReloadSwiss RS 52 | <<locked>> | 80% | 51,213 psi | 79% | 2949 fps | 99.9% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 41,423 psi | 64% | 2812 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 34,954 psi | 54% | 2625 fps | 96.3% |
| ReloadSwiss RS 70 | 53.4 gr | 80% | 34,301 psi | 53% | 2628 fps | 95.3% |
| Rottweil R 901 | <<locked>> | 80% | 55,143 psi | 85% | 2867 fps | 100% |
| Rottweil R 902 | <<locked>> | 80% | 48,573 psi | 75% | 2789 fps | 100% |
| Rottweil R 903 | <<locked>> | 80% | 42,250 psi | 65% | 2717 fps | 99.7% |
| Rottweil R 904 | <<locked>> | 96% | 52,881 psi | 81% | 2917 fps | 95.7% |
| Rottweil R 905 | <<locked>> | 94% | 46,209 psi | 71% | 2854 fps | 95.6% |
| Rottweil R 907 | <<locked>> | 82% | 42,206 psi | 65% | 2690 fps | 95.4% |
| Shooters World Long Rifle | <<locked>> | 80% | 38,566 psi | 59% | 2615 fps | 96.4% |
| Shooters World Match Rifle | <<locked>> | 80% | 52,214 psi | 80% | 2864 fps | 100% |
| Shooters World Precision | <<locked>> | 80% | 46,673 psi | 72% | 2772 fps | 100% |
| Shooters World SW4350 | <<locked>> | 82% | 39,233 psi | 60% | 2648 fps | 95.4% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 43,149 psi | 66% | 2766 fps | 99.4% |
| SNPE Vectan SP 7 | <<locked>> | 80% | 52,939 psi | 81% | 2890 fps | 99.6% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 50,517 psi | 78% | 2858 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 51,909 psi | 80% | 2772 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 43,772 psi | 67% | 2638 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 82% | 40,393 psi | 62% | 2615 fps | 95.6% |
| SNPE Vectan Tubal 8000 | <<locked>> | 94% | 45,774 psi | 70% | 2848 fps | 95.5% |
| Somchem S335 | <<locked>> | 80% | 51,605 psi | 79% | 2772 fps | 100% |
| Somchem S341 | <<locked>> | 80% | 52,736 psi | 81% | 2881 fps | 100% |
| Somchem S355 | <<locked>> | 80% | 42,554 psi | 65% | 2717 fps | 99.6% |
| Somchem S361 | <<locked>> | 96% | 54,418 psi | 84% | 2907 fps | 95.1% |
| Somchem S365 | <<locked>> | 80% | 31,633 psi | 49% | 2559 fps | 98.6% |
| Somchem S385 | <<locked>> | 90% | 41,249 psi | 63% | 2720 fps | 95.1% |
| Vihtavuori N133 | <<locked>> | 80% | 52,431 psi | 81% | 2759 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 48,733 psi | 75% | 2756 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 49,066 psi | 75% | 2769 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 40,741 psi | 63% | 2651 fps | 99.9% |
| Vihtavuori N160 | <<locked>> | 80% | 36,579 psi | 56% | 2612 fps | 97% |
| Vihtavuori N165 | <<locked>> | 96% | 43,163 psi | 66% | 2749 fps | 95.2% |
| Vihtavuori N530 | <<locked>> | 80% | 54,462 psi | 84% | 2887 fps | 100% |
| Vihtavuori N540 | <<locked>> | 80% | 47,268 psi | 73% | 2759 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 36,143 psi | 56% | 2608 fps | 96.6% |
| Vihtavuori N555 | <<locked>> | 82% | 29,399 psi | 45% | 2497 fps | 95% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 35,882 psi | 55% | 2582 fps | 98.8% |
| Winchester 760 | <<locked>> | 82% | 39,900 psi | 61% | 2717 fps | 95.4% |
| Winchester StaBALL HD | <<locked>> | 86% | 27,108 psi | 42% | 2497 fps | 95.4% |
| Winchester StaBALL Match | <<locked>> | 80% | 50,502 psi | 78% | 2867 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 96% | 46,702 psi | 72% | 2822 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 116 powders for .280 Ackley Improved loaded with the .284 | 140gr | Sierra Pro-Hunter. Alliant Reloder-26 delivers the highest muzzle velocity at 3,123 fps; across all powders the maximum-charge window runs from 1,837 fps to 3,123 fps. Accurate 3100 gives the best case fill at 100 %, and 116 of the 116 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (448 MPa), the top charges use 56–90 %, leaving at least 10 % headroom. The 140.0 gr projectile in 0.284" calls for a 1:12.5 twist; slower twists will usually not stabilise this weight. Accurate 3100, Accurate MAGPRO, ADI AR 2209 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, Hodgdon Superformance, Alliant Reloder-17 rank at the top here: for .280 Ackley Improved with the .284 | 140gr | Sierra Pro-Hunter they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, Accurate MAGPRO, Baschieri & Pellagri 109, Hodgdon H1000 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.