Load Specifications
Bullet Manufacturer:Sierra
Bullet Weight:150 gr
Bullet Diameter:0.284"
Bullet Length:<<locked>>
Caliber:.280 Ackley Improved load data
Case Length (l3):2.54"
Cartridge Length (C.O.L.):<<locked>>
Case Capacity:74 Grains of Water
Primer Size:Large Rifle (LR)
Barrel Length:24"
Max. allowed Pressure:65,000 psi
Recommended Twist Rate:1:12.0
Load data in caliber .280 Ackley Improved with .284 | 150gr | Sierra GameKing bullet and 103 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.
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% | 58,392 psi | 90% | 2795 fps | 100% |
| Accurate 2700 | <<locked>> | 84% | 55,970 psi | 86% | 2818 fps | 98.7% |
| Accurate 3100ᴾ | <<locked>> | 100% | 53,780 psi | 83% | 2861 fps | 99.5% |
| Accurate 4064 | <<locked>> | 84% | 55,187 psi | 85% | 2802 fps | 100% |
| Accurate 4350 | <<locked>> | 92% | 55,927 psi | 86% | 2910 fps | 100% |
| Accurate MAGPROᴾ | <<locked>> | 100% | 55,869 psi | 86% | 2999 fps | 96.1% |
| ADI AR 2206H | <<locked>> | 82% | 57,566 psi | 89% | 2881 fps | 100% |
| ADI AR 2208 | <<locked>> | 86% | 55,187 psi | 85% | 2835 fps | 100% |
| ADI AR 2209 | <<locked>> | 98% | 56,898 psi | 88% | 2953 fps | 98.3% |
| ADI AR 2213ᴾ | <<locked>> | 100% | 54,679 psi | 84% | 2946 fps | 96.8% |
| Alliant Power Pro 2000-MR | <<locked>> | 84% | 58,653 psi | 90% | 3018 fps | 100% |
| Alliant Reloder- TS 15.5 | <<locked>> | 86% | 55,999 psi | 86% | 2858 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 84% | 56,434 psi | 87% | 2884 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 94% | 56,797 psi | 87% | 2969 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 90% | 58,146 psi | 89% | 2992 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 98% | 56,347 psi | 87% | 2943 fps | 98.3% |
| Alliant Reloder-22ᴾ | <<locked>> | 100% | 53,534 psi | 82% | 2943 fps | 98% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 50,343 psi | 77% | 2874 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 44,019 psi | 68% | 2802 fps | 99% |
| Alliant Reloder-26ᴾ | <<locked>> | 100% | 58,131 psi | 89% | 3074 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 82% | 57,696 psi | 89% | 2900 fps | 100% |
| Bofors RP15ᴾ | <<locked>> | 100% | 48,907 psi | 75% | 2864 fps | 97% |
| Bofors RP3 | <<locked>> | 86% | 57,116 psi | 88% | 2877 fps | 100% |
| Bofors RP5ᴾ | <<locked>> | 100% | 53,534 psi | 82% | 2943 fps | 98% |
| Bofors RP7 | <<locked>> | 90% | 56,463 psi | 87% | 2864 fps | 99% |
| Hodgdon H380 | <<locked>> | 86% | 57,537 psi | 89% | 2897 fps | 100% |
| Hodgdon H414 | <<locked>> | 92% | 58,160 psi | 89% | 2966 fps | 99.5% |
| Hodgdon H4350 | <<locked>> | 90% | 57,899 psi | 89% | 2923 fps | 98.7% |
| Hodgdon H4831ᴾ | <<locked>> | 100% | 58,697 psi | 90% | 2953 fps | 96.9% |
| Hodgdon H4831 SCᴾ | <<locked>> | 100% | 57,392 psi | 88% | 2933 fps | 96.7% |
| Hodgdon H4895 | <<locked>> | 82% | 58,204 psi | 90% | 2887 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 96% | 57,116 psi | 88% | 2890 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 84% | 58,784 psi | 90% | 2930 fps | 100% |
| Hodgdon Superformance | <<locked>> | 92% | 58,726 psi | 90% | 3005 fps | 99.4% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,434 psi | 56% | 1775 fps | 100% |
| Hodgdon VARGET | <<locked>> | 82% | 55,811 psi | 86% | 2841 fps | 100% |
| IMR 4064 | <<locked>> | 86% | 58,131 psi | 89% | 2867 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 84% | 57,493 psi | 88% | 2854 fps | 99.4% |
| IMR 4350 | <<locked>> | 94% | 57,435 psi | 88% | 2897 fps | 99.1% |
| IMR 4451 Enduron | <<locked>> | 90% | 57,899 psi | 89% | 2887 fps | 99.4% |
| IMR 4831 | <<locked>> | 94% | 56,376 psi | 87% | 2904 fps | 100% |
| IMR 4895 | <<locked>> | 84% | 57,928 psi | 89% | 2910 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 98% | 56,304 psi | 87% | 2881 fps | 96.7% |
| IMR 7828 SSCᴾ | <<locked>> | 100% | 52,112 psi | 80% | 2917 fps | 96.3% |
| Lovex D073.6 | <<locked>> | 82% | 58,320 psi | 90% | 2854 fps | 100% |
| Lovex S060 | <<locked>> | 82% | 56,463 psi | 87% | 2805 fps | 100% |
| Lovex S062 | <<locked>> | 86% | 58,610 psi | 90% | 2864 fps | 100% |
| Lovex S065 | <<locked>> | 92% | 58,088 psi | 89% | 2884 fps | 99.9% |
| Lovex S070 | <<locked>> | 92% | 55,869 psi | 86% | 2874 fps | 99.4% |
| Lovex S071ᴾ | <<locked>> | 100% | 44,628 psi | 69% | 2710 fps | 98.3% |
| Norma 201 | <<locked>> | 82% | 56,231 psi | 87% | 2822 fps | 100% |
| Norma 202 | <<locked>> | 82% | 57,014 psi | 88% | 2818 fps | 100% |
| Norma 203B | <<locked>> | 84% | 55,724 psi | 86% | 2867 fps | 100% |
| Norma 204 | <<locked>> | 94% | 58,392 psi | 90% | 2953 fps | 98.4% |
| Norma MRPᴾ | <<locked>> | 100% | 56,869 psi | 87% | 3028 fps | 99.5% |
| Norma URP | <<locked>> | 94% | 58,160 psi | 89% | 2949 fps | 100% |
| Ramshot Big Game | <<locked>> | 84% | 56,565 psi | 87% | 2894 fps | 100% |
| Ramshot Grandᴾ | <<locked>> | 100% | 52,185 psi | 80% | 2930 fps | 96.7% |
| Ramshot Hunter | <<locked>> | 94% | 57,130 psi | 88% | 2953 fps | 99.8% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 46,557 psi | 72% | 2805 fps | 97.2% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,101 psi | 57% | 1818 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 86% | 57,435 psi | 88% | 2881 fps | 99.6% |
| ReloadSwiss RS 52 | <<locked>> | 82% | 57,537 psi | 89% | 2949 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 88% | 57,580 psi | 89% | 2982 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 92% | 55,956 psi | 86% | 2936 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 94% | 58,320 psi | 90% | 3022 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 42,888 psi | 66% | 2815 fps | 97.1% |
| Rottweil R 902 | <<locked>> | 84% | 57,000 psi | 88% | 2825 fps | 100% |
| Rottweil R 903 | <<locked>> | 88% | 57,261 psi | 88% | 2874 fps | 100% |
| Rottweil R 904 | <<locked>> | 98% | 58,711 psi | 90% | 2923 fps | 97.6% |
| Rottweil R 905 | <<locked>> | 98% | 55,492 psi | 85% | 2930 fps | 98.3% |
| Rottweil R 907 | <<locked>> | 90% | 56,463 psi | 87% | 2864 fps | 99% |
| Shooters World Long Rifle | <<locked>> | 92% | 58,088 psi | 89% | 2884 fps | 99.9% |
| Shooters World Match Rifle | <<locked>> | 82% | 58,320 psi | 90% | 2854 fps | 100% |
| Shooters World Precision | <<locked>> | 86% | 58,610 psi | 90% | 2864 fps | 100% |
| Shooters World SW4350 | <<locked>> | 92% | 55,869 psi | 86% | 2874 fps | 99.4% |
| SNPE Vectan SP 11 | <<locked>> | 88% | 58,697 psi | 90% | 2933 fps | 100% |
| SNPE Vectan SP 9 | <<locked>> | 82% | 56,101 psi | 86% | 2851 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 82% | 57,174 psi | 88% | 2753 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 88% | 58,073 psi | 89% | 2753 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 92% | 58,030 psi | 89% | 2841 fps | 99.4% |
| SNPE Vectan Tubal 8000ᴾ | <<locked>> | 100% | 58,653 psi | 90% | 2979 fps | 98.7% |
| Somchem S335 | <<locked>> | 82% | 56,681 psi | 87% | 2749 fps | 100% |
| Somchem S341 | <<locked>> | 82% | 58,711 psi | 90% | 2874 fps | 100% |
| Somchem S355 | <<locked>> | 88% | 57,087 psi | 88% | 2867 fps | 100% |
| Somchem S361 | <<locked>> | 96% | 56,913 psi | 88% | 2864 fps | 96.5% |
| Somchem S365 | <<locked>> | 96% | 57,667 psi | 89% | 2949 fps | 100% |
| Somchem S385 | <<locked>> | 98% | 56,072 psi | 86% | 2904 fps | 98.9% |
| Vihtavuori N133 | <<locked>> | 82% | 57,711 psi | 89% | 2733 fps | 100% |
| Vihtavuori N135 | <<locked>> | 84% | 57,232 psi | 88% | 2779 fps | 100% |
| Vihtavuori N140 | <<locked>> | 84% | 57,638 psi | 89% | 2799 fps | 100% |
| Vihtavuori N150 | <<locked>> | 90% | 58,465 psi | 90% | 2841 fps | 100% |
| Vihtavuori N160 | <<locked>> | 92% | 56,724 psi | 87% | 2887 fps | 100% |
| Vihtavuori N165ᴾ | <<locked>> | 100% | 51,866 psi | 80% | 2822 fps | 98% |
| Vihtavuori N540 | <<locked>> | 84% | 55,782 psi | 86% | 2795 fps | 100% |
| Vihtavuori N550 | <<locked>> | 92% | 55,941 psi | 86% | 2897 fps | 100% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 56,565 psi | 87% | 2956 fps | 100% |
| Vihtavuori N560ᴾ | <<locked>> | 100% | 57,188 psi | 88% | 3018 fps | 97% |
| Winchester 6.5 StaBALL | <<locked>> | 92% | 56,550 psi | 87% | 2858 fps | 100% |
| Winchester 760 | <<locked>> | 92% | 58,494 psi | 90% | 2969 fps | 99.5% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 45,600 psi | 70% | 2933 fps | 100% |
| Winchester StaBALL Match | <<locked>> | 82% | 56,275 psi | 87% | 2861 fps | 100% |
| Winchester Supreme 780ᴾ | <<locked>> | 100% | 56,318 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% | 51,474 psi | 79% | 2703 fps | 100% |
| Accurate 2700 | <<locked>> | 80% | 49,342 psi | 76% | 2710 fps | 97.7% |
| Accurate 3100 | <<locked>> | 86% | 33,402 psi | 51% | 2470 fps | 95% |
| Accurate 4064 | <<locked>> | 80% | 48,733 psi | 75% | 2707 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 37,144 psi | 57% | 2572 fps | 98% |
| Accurate MAGPRO | <<locked>> | 98% | 52,054 psi | 80% | 2936 fps | 95.2% |
| ADI AR 2206H | <<locked>> | 80% | 54,143 psi | 83% | 2828 fps | 100% |
| ADI AR 2208 | <<locked>> | 80% | 45,919 psi | 71% | 2680 fps | 99.7% |
| ADI AR 2209 | <<locked>> | 90% | 43,874 psi | 67% | 2720 fps | 95.4% |
| ADI AR 2213 | <<locked>> | 96% | 47,863 psi | 74% | 2825 fps | 95% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 50,749 psi | 78% | 2894 fps | 100% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 46,543 psi | 72% | 2710 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 49,676 psi | 76% | 2776 fps | 100% |
| Alliant Reloder-16 | 48.3 gr | 80% | 36,230 psi | 56% | 2582 fps | 98.1% |
| Alliant Reloder-17 | <<locked>> | 80% | 40,988 psi | 63% | 2707 fps | 99.9% |
| Alliant Reloder-19 | <<locked>> | 90% | 43,482 psi | 67% | 2717 fps | 95.5% |
| Alliant Reloder-22 | <<locked>> | 94% | 43,743 psi | 67% | 2766 fps | 95.7% |
| Alliant Reloder-23 | <<locked>> | 80% | 26,542 psi | 41% | 2333 fps | 95.6% |
| Alliant Reloder-25 | <<locked>> | 92% | 34,069 psi | 52% | 2566 fps | 95.8% |
| Alliant Reloder-26 | 56 gr | 84% | 32,532 psi | 50% | 2566 fps | 96.1% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 54,070 psi | 83% | 2848 fps | 100% |
| Bofors RP15 | <<locked>> | 96% | 43,105 psi | 66% | 2749 fps | 95.4% |
| Bofors RP3 | <<locked>> | 80% | 46,731 psi | 72% | 2717 fps | 100% |
| Bofors RP5 | <<locked>> | 94% | 43,743 psi | 67% | 2766 fps | 95.7% |
| Bofors RP7 | <<locked>> | 80% | 41,278 psi | 64% | 2592 fps | 96% |
| Hodgdon H380 | <<locked>> | 80% | 47,253 psi | 73% | 2730 fps | 99.4% |
| Hodgdon H414 | <<locked>> | 80% | 39,117 psi | 60% | 2618 fps | 95.9% |
| Hodgdon H4350 | <<locked>> | 80% | 41,959 psi | 65% | 2638 fps | 95.4% |
| Hodgdon H4831 | <<locked>> | 96% | 51,024 psi | 78% | 2828 fps | 95.2% |
| Hodgdon H4831 SC | <<locked>> | 96% | 50,212 psi | 77% | 2815 fps | 95% |
| Hodgdon H4895 | <<locked>> | 80% | 54,766 psi | 84% | 2838 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 33,808 psi | 52% | 2480 fps | 98.7% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 51,416 psi | 79% | 2822 fps | 100% |
| Hodgdon Superformance | <<locked>> | 80% | 38,072 psi | 59% | 2625 fps | 95% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,180 psi | 42% | 1588 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 52,243 psi | 80% | 2785 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 48,298 psi | 74% | 2713 fps | 99.9% |
| IMR 4166 Enduron | <<locked>> | 80% | 50,705 psi | 78% | 2746 fps | 98.6% |
| IMR 4350 | <<locked>> | 82% | 39,421 psi | 61% | 2572 fps | 95.4% |
| IMR 4451 Enduron | <<locked>> | 80% | 42,627 psi | 66% | 2618 fps | 96.8% |
| IMR 4831 | <<locked>> | 80% | 35,795 psi | 55% | 2526 fps | 97.7% |
| IMR 4895 | <<locked>> | 80% | 50,952 psi | 78% | 2805 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 94% | 49,879 psi | 77% | 2772 fps | 95.2% |
| IMR 7828 SSC | <<locked>> | 98% | 48,602 psi | 75% | 2851 fps | 95.4% |
| Lovex D073.6 | <<locked>> | 80% | 54,549 psi | 84% | 2805 fps | 100% |
| Lovex S060 | <<locked>> | 80% | 52,910 psi | 81% | 2753 fps | 100% |
| Lovex S062 | <<locked>> | 80% | 48,515 psi | 75% | 2713 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 40,147 psi | 62% | 2569 fps | 97.6% |
| Lovex S070 | <<locked>> | 80% | 38,508 psi | 59% | 2552 fps | 96% |
| Lovex S071 | <<locked>> | 92% | 34,519 psi | 53% | 2497 fps | 95.5% |
| Norma 201 | <<locked>> | 80% | 52,924 psi | 81% | 2772 fps | 100% |
| Norma 202 | <<locked>> | 80% | 53,606 psi | 82% | 2772 fps | 100% |
| Norma 203B | <<locked>> | 80% | 49,023 psi | 75% | 2762 fps | 100% |
| Norma 204 | <<locked>> | 86% | 44,570 psi | 69% | 2717 fps | 95.5% |
| Norma MRP | <<locked>> | 88% | 37,463 psi | 58% | 2657 fps | 95.1% |
| Norma URP | <<locked>> | 80% | 37,043 psi | 57% | 2569 fps | 97.9% |
| Ramshot Big Game | <<locked>> | 80% | 49,226 psi | 76% | 2782 fps | 100% |
| Ramshot Grand | <<locked>> | 98% | 48,762 psi | 75% | 2867 fps | 95.8% |
| Ramshot Hunter | <<locked>> | 80% | 35,795 psi | 55% | 2549 fps | 95.7% |
| Ramshot Magnum | <<locked>> | 96% | 40,321 psi | 62% | 2677 fps | 95.3% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,644 psi | 43% | 1624 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 47,239 psi | 73% | 2713 fps | 98.5% |
| ReloadSwiss RS 52 | <<locked>> | 80% | 53,693 psi | 83% | 2894 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 43,555 psi | 67% | 2762 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 36,941 psi | 57% | 2592 fps | 97.7% |
| ReloadSwiss RS 70 | 52.8 gr | 80% | 35,795 psi | 55% | 2592 fps | 96.9% |
| ReloadSwiss RS 76 | <<locked>> | 98% | 40,059 psi | 62% | 2749 fps | 96% |
| Rottweil R 902 | <<locked>> | 80% | 50,415 psi | 78% | 2726 fps | 100% |
| Rottweil R 903 | <<locked>> | 80% | 44,179 psi | 68% | 2667 fps | 100% |
| Rottweil R 904 | <<locked>> | 92% | 48,414 psi | 74% | 2756 fps | 95.5% |
| Rottweil R 905 | <<locked>> | 90% | 42,583 psi | 66% | 2697 fps | 95.4% |
| Rottweil R 907 | <<locked>> | 80% | 41,278 psi | 64% | 2592 fps | 96% |
| Shooters World Long Rifle | <<locked>> | 80% | 40,147 psi | 62% | 2569 fps | 97.6% |
| Shooters World Match Rifle | <<locked>> | 80% | 54,549 psi | 84% | 2805 fps | 100% |
| Shooters World Precision | <<locked>> | 80% | 48,515 psi | 75% | 2713 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 38,508 psi | 59% | 2552 fps | 96% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 45,136 psi | 69% | 2717 fps | 99.9% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 52,576 psi | 81% | 2799 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 53,693 psi | 83% | 2707 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 45,397 psi | 70% | 2575 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 39,334 psi | 61% | 2513 fps | 96.1% |
| SNPE Vectan Tubal 8000 | <<locked>> | 90% | 42,235 psi | 65% | 2694 fps | 95.3% |
| Somchem S335 | <<locked>> | 80% | 53,417 psi | 82% | 2703 fps | 100% |
| Somchem S341 | <<locked>> | 80% | 55,013 psi | 85% | 2822 fps | 100% |
| Somchem S355 | <<locked>> | 80% | 44,396 psi | 68% | 2664 fps | 99.9% |
| Somchem S361 | <<locked>> | 94% | 53,316 psi | 82% | 2805 fps | 95.7% |
| Somchem S365 | <<locked>> | 80% | 33,359 psi | 51% | 2523 fps | 99.5% |
| Somchem S385 | <<locked>> | 88% | 40,364 psi | 62% | 2625 fps | 95.7% |
| Vihtavuori N133 | <<locked>> | 80% | 54,230 psi | 83% | 2687 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 50,705 psi | 78% | 2690 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 50,995 psi | 78% | 2707 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 42,511 psi | 65% | 2595 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 38,348 psi | 59% | 2569 fps | 98.2% |
| Vihtavuori N165 | <<locked>> | 92% | 39,711 psi | 61% | 2598 fps | 95% |
| Vihtavuori N540 | <<locked>> | 80% | 49,197 psi | 76% | 2700 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 37,869 psi | 58% | 2569 fps | 97.9% |
| Vihtavuori N555 | <<locked>> | 80% | 29,167 psi | 45% | 2411 fps | 95.8% |
| Vihtavuori N560 | <<locked>> | 96% | 49,835 psi | 77% | 2894 fps | 95.3% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 37,565 psi | 58% | 2539 fps | 99.6% |
| Winchester 760 | <<locked>> | 80% | 39,117 psi | 60% | 2618 fps | 95.9% |
| Winchester StaBALL HD | <<locked>> | 82% | 25,034 psi | 39% | 2356 fps | 95.1% |
| Winchester StaBALL Match | <<locked>> | 80% | 52,678 psi | 81% | 2808 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 92% | 42,569 psi | 65% | 2664 fps | 95.1% |
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 103 powders for .280 Ackley Improved loaded with the .284 | 150gr | Sierra GameKing. Alliant Reloder-26 delivers the highest muzzle velocity at 3,074 fps; across all powders the maximum-charge window runs from 1,775 fps to 3,074 fps. Accurate 3100 gives the best case fill at 100 %, and 103 of the 103 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 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 | Sierra GameKing 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.