Load Specifications
Load data in caliber .280 Ackley Improved with .284 | 130gr | Sierra SP SSPistol bullet and 99 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are ReloadSwiss RS 60, ReloadSwiss RS 70 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 2015 | <<locked>> | 82% | 57,740 psi | 89% | 2963 fps | 100% |
| Accurate 2495 | <<locked>> | 86% | 57,725 psi | 89% | 2992 fps | 100% |
| Accurate 2700 | <<locked>> | 86% | 55,956 psi | 86% | 3002 fps | 97.6% |
| Accurate 3100ᴾ | <<locked>> | 100% | 48,733 psi | 75% | 2963 fps | 97.9% |
| Accurate 4064 | <<locked>> | 88% | 57,754 psi | 89% | 3048 fps | 100% |
| Accurate 4350 | <<locked>> | 96% | 58,450 psi | 90% | 3146 fps | 99.9% |
| ADI AR 2206H | <<locked>> | 84% | 57,203 psi | 88% | 3077 fps | 100% |
| ADI AR 2208 | <<locked>> | 90% | 58,218 psi | 90% | 3077 fps | 100% |
| ADI AR 2209ᴾ | <<locked>> | 100% | 56,202 psi | 86% | 3127 fps | 96.9% |
| ADI Benchmark 8208 | <<locked>> | 82% | 55,840 psi | 86% | 3022 fps | 100% |
| Alliant AR-Comp | <<locked>> | 82% | 57,479 psi | 88% | 2992 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 86% | 57,479 psi | 88% | 3209 fps | 100% |
| Alliant Reloder- TS 15.5 | <<locked>> | 88% | 55,288 psi | 85% | 3048 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 86% | 55,767 psi | 86% | 3074 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 96% | 55,317 psi | 85% | 3146 fps | 99.9% |
| Alliant Reloder-17 | <<locked>> | 92% | 57,029 psi | 88% | 3186 fps | 100% |
| Alliant Reloder-19ᴾ | <<locked>> | 100% | 55,071 psi | 85% | 3110 fps | 96.8% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 45,774 psi | 70% | 2986 fps | 99.8% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 40,248 psi | 62% | 2881 fps | 96.4% |
| Alliant Reloder-26ᴾ | <<locked>> | 100% | 52,388 psi | 81% | 3182 fps | 99.6% |
| Baschieri & Pellagri 107 | <<locked>> | 84% | 57,334 psi | 88% | 3094 fps | 99.9% |
| Bofors RP3 | <<locked>> | 88% | 56,333 psi | 87% | 3068 fps | 100% |
| Bofors RP7 | <<locked>> | 92% | 55,767 psi | 86% | 3038 fps | 97.8% |
| Hodgdon Benchmark | <<locked>> | 82% | 57,145 psi | 88% | 2999 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 82% | 55,738 psi | 86% | 3051 fps | 100% |
| Hodgdon H380 | <<locked>> | 88% | 56,898 psi | 88% | 3084 fps | 99.7% |
| Hodgdon H414 | <<locked>> | 94% | 57,101 psi | 88% | 3140 fps | 98.6% |
| Hodgdon H4350 | <<locked>> | 92% | 57,058 psi | 88% | 3100 fps | 97.4% |
| Hodgdon H4895 | <<locked>> | 84% | 57,841 psi | 89% | 3087 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 98% | 55,738 psi | 86% | 3071 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 86% | 57,957 psi | 89% | 3123 fps | 100% |
| Hodgdon Superformance | <<locked>> | 94% | 57,812 psi | 89% | 3182 fps | 98.4% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,013 psi | 55% | 1909 fps | 100% |
| Hodgdon VARGET | <<locked>> | 84% | 55,303 psi | 85% | 3035 fps | 100% |
| IMR 3031 | <<locked>> | 84% | 58,378 psi | 90% | 3068 fps | 100% |
| IMR 4064 | <<locked>> | 88% | 57,812 psi | 89% | 3064 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 86% | 57,276 psi | 88% | 3041 fps | 98.5% |
| IMR 4350 | <<locked>> | 96% | 56,449 psi | 87% | 3068 fps | 98% |
| IMR 4451 Enduron | <<locked>> | 92% | 57,551 psi | 89% | 3071 fps | 98.5% |
| IMR 4831 | <<locked>> | 98% | 58,798 psi | 90% | 3136 fps | 99.9% |
| IMR 4895 | <<locked>> | 86% | 57,232 psi | 88% | 3104 fps | 100% |
| IMR 8208 XBR | <<locked>> | 82% | 55,840 psi | 86% | 3022 fps | 100% |
| Lovex D073.6 | <<locked>> | 84% | 57,493 psi | 88% | 3048 fps | 100% |
| Lovex S060 | <<locked>> | 84% | 56,057 psi | 86% | 2999 fps | 100% |
| Lovex S062 | <<locked>> | 88% | 57,798 psi | 89% | 3058 fps | 100% |
| Lovex S065 | <<locked>> | 94% | 57,406 psi | 88% | 3068 fps | 99.3% |
| Lovex S070 | <<locked>> | 96% | 58,697 psi | 90% | 3110 fps | 98.9% |
| Norma 201 | <<locked>> | 84% | 55,825 psi | 86% | 3018 fps | 100% |
| Norma 202 | <<locked>> | 84% | 56,478 psi | 87% | 3018 fps | 100% |
| Norma 203B | <<locked>> | 88% | 58,436 psi | 90% | 3110 fps | 100% |
| Norma 204 | <<locked>> | 96% | 57,276 psi | 88% | 3120 fps | 97% |
| Norma MRPᴾ | <<locked>> | 100% | 51,634 psi | 79% | 3130 fps | 97.7% |
| Norma URP | <<locked>> | 96% | 57,145 psi | 88% | 3130 fps | 99.8% |
| Ramshot Big Game | <<locked>> | 86% | 55,579 psi | 86% | 3081 fps | 100% |
| Ramshot Hunter | <<locked>> | 96% | 55,782 psi | 86% | 3127 fps | 99% |
| Ramshot TAC | <<locked>> | 82% | 56,086 psi | 86% | 3041 fps | 99.3% |
| Ramshot Wild Boar | <<locked>> | 82% | 56,072 psi | 86% | 3061 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 36,564 psi | 56% | 1952 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 88% | 56,840 psi | 87% | 3061 fps | 98.9% |
| ReloadSwiss RS 52 | <<locked>> | 84% | 56,449 psi | 87% | 3143 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 90% | 56,405 psi | 87% | 3179 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 96% | 58,508 psi | 90% | 3173 fps | 99.9% |
| ReloadSwiss RS 70 | <<locked>> | 96% | 57,087 psi | 88% | 3199 fps | 99.8% |
| Rottweil R 901 | <<locked>> | 82% | 56,695 psi | 87% | 2999 fps | 100% |
| Rottweil R 902 | <<locked>> | 86% | 56,478 psi | 87% | 3018 fps | 100% |
| Rottweil R 903 | <<locked>> | 90% | 56,202 psi | 86% | 3061 fps | 100% |
| Rottweil R 904ᴾ | <<locked>> | 100% | 57,856 psi | 89% | 3094 fps | 96% |
| Rottweil R 905ᴾ | <<locked>> | 100% | 54,085 psi | 83% | 3094 fps | 96.8% |
| Rottweil R 907 | <<locked>> | 92% | 55,767 psi | 86% | 3038 fps | 97.8% |
| Shooters World Long Rifle | <<locked>> | 94% | 57,406 psi | 88% | 3068 fps | 99.3% |
| Shooters World Match Rifle | <<locked>> | 84% | 57,493 psi | 88% | 3048 fps | 100% |
| Shooters World Precision | <<locked>> | 88% | 57,798 psi | 89% | 3058 fps | 100% |
| Shooters World SW4350 | <<locked>> | 96% | 58,697 psi | 90% | 3110 fps | 98.9% |
| SNPE Vectan SP 11 | <<locked>> | 90% | 57,943 psi | 89% | 3123 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 84% | 58,726 psi | 90% | 3081 fps | 99.7% |
| SNPE Vectan SP 9 | <<locked>> | 84% | 55,564 psi | 85% | 3045 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 84% | 56,956 psi | 88% | 2953 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 90% | 57,638 psi | 89% | 2949 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 94% | 57,479 psi | 88% | 3018 fps | 98.5% |
| SNPE Vectan Tubal 8000ᴾ | <<locked>> | 100% | 53,592 psi | 82% | 3084 fps | 96.6% |
| Somchem S335 | <<locked>> | 84% | 56,449 psi | 87% | 2946 fps | 100% |
| Somchem S341 | <<locked>> | 84% | 58,421 psi | 90% | 3068 fps | 100% |
| Somchem S355 | <<locked>> | 90% | 56,289 psi | 87% | 3058 fps | 100% |
| Somchem S365 | <<locked>> | 98% | 55,985 psi | 86% | 3136 fps | 100% |
| Somchem S385ᴾ | <<locked>> | 100% | 54,911 psi | 84% | 3071 fps | 97.7% |
| Vihtavuori N133 | <<locked>> | 84% | 57,363 psi | 88% | 2933 fps | 100% |
| Vihtavuori N135 | <<locked>> | 86% | 56,666 psi | 87% | 2979 fps | 100% |
| Vihtavuori N140 | <<locked>> | 86% | 57,261 psi | 88% | 2995 fps | 100% |
| Vihtavuori N150 | <<locked>> | 92% | 57,812 psi | 89% | 3031 fps | 100% |
| Vihtavuori N160 | <<locked>> | 94% | 55,883 psi | 86% | 3071 fps | 99.7% |
| Vihtavuori N530 | <<locked>> | 82% | 56,434 psi | 87% | 3022 fps | 100% |
| Vihtavuori N540 | <<locked>> | 86% | 55,434 psi | 85% | 2989 fps | 100% |
| Vihtavuori N550 | <<locked>> | 96% | 58,653 psi | 90% | 3133 fps | 99.8% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 51,271 psi | 79% | 3074 fps | 99.8% |
| Winchester 6.5 StaBALL | <<locked>> | 94% | 55,666 psi | 86% | 3041 fps | 100% |
| Winchester 748 | <<locked>> | 82% | 57,014 psi | 88% | 3074 fps | 100% |
| Winchester 760 | <<locked>> | 94% | 57,334 psi | 88% | 3146 fps | 98.6% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 41,336 psi | 64% | 3018 fps | 100% |
| Winchester StaBALL Match | <<locked>> | 84% | 55,724 psi | 86% | 3054 fps | 100% |
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 2015 | <<locked>> | 80% | 54,331 psi | 84% | 2913 fps | 100% |
| Accurate 2495 | <<locked>> | 80% | 47,355 psi | 73% | 2841 fps | 100% |
| Accurate 2700 | <<locked>> | 80% | 45,890 psi | 71% | 2822 fps | 95.4% |
| Accurate 3100 | <<locked>> | 94% | 39,668 psi | 61% | 2782 fps | 95.6% |
| Accurate 4064 | <<locked>> | 80% | 44,802 psi | 69% | 2841 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 33,547 psi | 52% | 2657 fps | 95.2% |
| ADI AR 2206H | <<locked>> | 80% | 50,285 psi | 77% | 2963 fps | 99.8% |
| ADI AR 2208 | <<locked>> | 80% | 42,714 psi | 66% | 2802 fps | 98.5% |
| ADI AR 2209 | <<locked>> | 96% | 49,110 psi | 76% | 2999 fps | 95.2% |
| ADI Benchmark 8208 | <<locked>> | 80% | 52,373 psi | 81% | 2966 fps | 100% |
| Alliant AR-Comp | <<locked>> | 80% | 53,925 psi | 83% | 2946 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 46,717 psi | 72% | 3015 fps | 99.3% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 42,975 psi | 66% | 2828 fps | 99.5% |
| Alliant Reloder-15 | <<locked>> | 80% | 45,861 psi | 71% | 2897 fps | 99.2% |
| Alliant Reloder-16 | 49.7 gr | 80% | 33,330 psi | 51% | 2671 fps | 95.3% |
| Alliant Reloder-17 | <<locked>> | 80% | 37,405 psi | 58% | 2805 fps | 98.5% |
| Alliant Reloder-19 | <<locked>> | 96% | 48,269 psi | 74% | 2986 fps | 95.1% |
| Alliant Reloder-23 | <<locked>> | 86% | 29,385 psi | 45% | 2575 fps | 95.2% |
| Alliant Reloder-25 | <<locked>> | 98% | 37,739 psi | 58% | 2815 fps | 95.3% |
| Alliant Reloder-26 | <<locked>> | 90% | 36,318 psi | 56% | 2828 fps | 95.8% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 49,995 psi | 77% | 2972 fps | 99.4% |
| Bofors RP3 | <<locked>> | 80% | 43,047 psi | 66% | 2838 fps | 99.6% |
| Bofors RP7 | <<locked>> | 86% | 46,325 psi | 71% | 2867 fps | 95.8% |
| Hodgdon Benchmark | <<locked>> | 80% | 53,954 psi | 83% | 2953 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 80% | 52,228 psi | 80% | 2995 fps | 100% |
| Hodgdon H380 | <<locked>> | 80% | 43,468 psi | 67% | 2841 fps | 97.8% |
| Hodgdon H414 | <<locked>> | 86% | 43,772 psi | 67% | 2897 fps | 95.8% |
| Hodgdon H4350 | <<locked>> | 86% | 47,268 psi | 73% | 2923 fps | 95.2% |
| Hodgdon H4895 | <<locked>> | 80% | 50,836 psi | 78% | 2976 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 30,850 psi | 47% | 2566 fps | 96.2% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 47,297 psi | 73% | 2949 fps | 99.9% |
| Hodgdon Superformance | <<locked>> | 86% | 43,163 psi | 66% | 2907 fps | 95% |
| Hodgdon TrailBoss | <<locked>> | 80% | 26,861 psi | 41% | 1706 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 48,805 psi | 75% | 2923 fps | 99.9% |
| IMR 3031 | <<locked>> | 80% | 51,140 psi | 79% | 2963 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 44,889 psi | 69% | 2841 fps | 99.1% |
| IMR 4166 Enduron | <<locked>> | 80% | 47,253 psi | 73% | 2864 fps | 96.6% |
| IMR 4350 | <<locked>> | 88% | 43,845 psi | 67% | 2838 fps | 95.1% |
| IMR 4451 Enduron | <<locked>> | 82% | 42,250 psi | 65% | 2785 fps | 95.1% |
| IMR 4831 | <<locked>> | 82% | 34,824 psi | 54% | 2674 fps | 95.9% |
| IMR 4895 | <<locked>> | 80% | 47,050 psi | 72% | 2930 fps | 99.6% |
| IMR 8208 XBR | <<locked>> | 80% | 52,373 psi | 81% | 2966 fps | 100% |
| Lovex D073.6 | <<locked>> | 80% | 50,328 psi | 77% | 2940 fps | 100% |
| Lovex S060 | <<locked>> | 80% | 49,806 psi | 77% | 2894 fps | 99.8% |
| Lovex S062 | <<locked>> | 80% | 45,237 psi | 70% | 2844 fps | 99.9% |
| Lovex S065 | <<locked>> | 80% | 37,130 psi | 57% | 2671 fps | 95.1% |
| Lovex S070 | <<locked>> | 86% | 42,888 psi | 66% | 2822 fps | 95.7% |
| Norma 201 | <<locked>> | 80% | 49,240 psi | 76% | 2910 fps | 100% |
| Norma 202 | <<locked>> | 80% | 49,821 psi | 77% | 2913 fps | 100% |
| Norma 203B | <<locked>> | 80% | 45,252 psi | 70% | 2884 fps | 99.4% |
| Norma 204 | <<locked>> | 92% | 50,067 psi | 77% | 2999 fps | 95.4% |
| Norma MRP | <<locked>> | 96% | 44,831 psi | 69% | 2995 fps | 95.9% |
| Norma URP | <<locked>> | 80% | 33,721 psi | 52% | 2661 fps | 95.2% |
| Ramshot Big Game | <<locked>> | 80% | 45,469 psi | 70% | 2904 fps | 99.3% |
| Ramshot Hunter | <<locked>> | 86% | 40,147 psi | 62% | 2825 fps | 95.6% |
| Ramshot TAC | <<locked>> | 80% | 52,446 psi | 81% | 2982 fps | 98.9% |
| Ramshot Wild Boar | <<locked>> | 80% | 52,359 psi | 81% | 3002 fps | 99.9% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,224 psi | 42% | 1745 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 43,787 psi | 67% | 2825 fps | 96.4% |
| ReloadSwiss RS 52 | <<locked>> | 80% | 49,240 psi | 76% | 3018 fps | 99.5% |
| ReloadSwiss RS 60 | 53.5 gr | 80% | 39,784 psi | 61% | 2874 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 82% | 35,766 psi | 55% | 2733 fps | 95.7% |
| ReloadSwiss RS 70 | 57.1 gr | 84% | 37,768 psi | 58% | 2805 fps | 95.8% |
| Rottweil R 901 | <<locked>> | 80% | 53,447 psi | 82% | 2946 fps | 100% |
| Rottweil R 902 | <<locked>> | 80% | 46,949 psi | 72% | 2861 fps | 99.9% |
| Rottweil R 903 | <<locked>> | 80% | 40,509 psi | 62% | 2779 fps | 99.1% |
| Rottweil R 904 | <<locked>> | 98% | 54,114 psi | 83% | 3031 fps | 95.2% |
| Rottweil R 905 | <<locked>> | 96% | 47,384 psi | 73% | 2969 fps | 95.1% |
| Rottweil R 907 | <<locked>> | 86% | 46,325 psi | 71% | 2867 fps | 95.8% |
| Shooters World Long Rifle | <<locked>> | 80% | 37,130 psi | 57% | 2671 fps | 95.1% |
| Shooters World Match Rifle | <<locked>> | 80% | 50,328 psi | 77% | 2940 fps | 100% |
| Shooters World Precision | <<locked>> | 80% | 45,237 psi | 70% | 2844 fps | 99.9% |
| Shooters World SW4350 | <<locked>> | 86% | 42,888 psi | 66% | 2822 fps | 95.7% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 41,510 psi | 64% | 2831 fps | 98.8% |
| SNPE Vectan SP 7 | <<locked>> | 80% | 51,343 psi | 79% | 2963 fps | 99.1% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 48,892 psi | 75% | 2930 fps | 99.7% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 50,357 psi | 77% | 2854 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 42,337 psi | 65% | 2710 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 84% | 41,495 psi | 64% | 2730 fps | 95.1% |
| SNPE Vectan Tubal 8000 | <<locked>> | 98% | 49,995 psi | 77% | 3022 fps | 95.8% |
| Somchem S335 | <<locked>> | 80% | 49,951 psi | 77% | 2848 fps | 100% |
| Somchem S341 | <<locked>> | 80% | 50,850 psi | 78% | 2953 fps | 99.8% |
| Somchem S355 | <<locked>> | 80% | 40,959 psi | 63% | 2779 fps | 99% |
| Somchem S365 | <<locked>> | 80% | 30,342 psi | 47% | 2608 fps | 97.5% |
| Somchem S385 | <<locked>> | 94% | 44,976 psi | 69% | 2890 fps | 95.4% |
| Vihtavuori N133 | <<locked>> | 80% | 50,821 psi | 78% | 2841 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 46,934 psi | 72% | 2835 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 47,297 psi | 73% | 2844 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 39,131 psi | 60% | 2710 fps | 99.5% |
| Vihtavuori N160 | <<locked>> | 80% | 35,012 psi | 54% | 2661 fps | 95.7% |
| Vihtavuori N530 | <<locked>> | 80% | 52,837 psi | 81% | 2966 fps | 100% |
| Vihtavuori N540 | <<locked>> | 80% | 45,513 psi | 70% | 2828 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 34,548 psi | 53% | 2657 fps | 95.2% |
| Vihtavuori N555 | <<locked>> | 86% | 32,068 psi | 49% | 2657 fps | 95.3% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 34,563 psi | 53% | 2635 fps | 97.9% |
| Winchester 748 | <<locked>> | 80% | 53,127 psi | 82% | 3015 fps | 100% |
| Winchester 760 | <<locked>> | 86% | 44,005 psi | 68% | 2900 fps | 95.8% |
| Winchester StaBALL HD | <<locked>> | 90% | 29,573 psi | 45% | 2661 fps | 96% |
| Winchester StaBALL Match | <<locked>> | 80% | 48,733 psi | 75% | 2936 fps | 99.9% |
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 116 powders for .280 Ackley Improved loaded with the .284 | 130gr | Sierra SP SSPistol. Alliant Power Pro 2000-MR delivers the highest muzzle velocity at 3,209 fps; across all powders the maximum-charge window runs from 1,909 fps to 3,209 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 55–90 %, leaving at least 10 % headroom. The 130.0 gr projectile in 0.284" calls for a 1:13.5 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 60, ReloadSwiss RS 70, Alliant Reloder-16 rank at the top here: for .280 Ackley Improved with the .284 | 130gr | Sierra SP SSPistol they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, Accurate MAGPRO, ADI AR 2213, Bofors RP15 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.