Load Specifications
Bullet:.284 | 150gr | Barnes X BT
Bullet Manufacturer:Barnes
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:1:10.5
Load data in caliber .280 Ackley Improved with .284 | 150gr | Barnes X BT bullet and 100 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Alliant Reloder-26, 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 2495 | <<locked>> | 82% | 57,914 psi | 89% | 2756 fps | 100% |
| Accurate 2700 | <<locked>> | 84% | 57,566 psi | 89% | 2812 fps | 98.8% |
| Accurate 3100ᴾ | <<locked>> | 100% | 56,028 psi | 86% | 2867 fps | 99.6% |
| Accurate 4064 | <<locked>> | 84% | 58,102 psi | 89% | 2812 fps | 100% |
| Accurate 4350 | <<locked>> | 92% | 58,146 psi | 89% | 2917 fps | 100% |
| Accurate MAGPROᴾ | <<locked>> | 100% | 57,246 psi | 88% | 2995 fps | 96.1% |
| ADI AR 2208 | <<locked>> | 86% | 56,550 psi | 87% | 2828 fps | 100% |
| ADI AR 2209 | <<locked>> | 98% | 58,073 psi | 89% | 2946 fps | 98.3% |
| ADI AR 2213ᴾ | <<locked>> | 100% | 55,593 psi | 86% | 2933 fps | 96.6% |
| Alliant Power Pro 2000-MR | <<locked>> | 82% | 55,666 psi | 86% | 2949 fps | 100% |
| Alliant Power Pro Varmint | <<locked>> | 98% | 58,175 psi | 89% | 2943 fps | 98.3% |
| Alliant Power Pro Varmint | <<locked>> | 98% | 58,175 psi | 89% | 2943 fps | 98.3% |
| Alliant Reloder- TS 15.5 | <<locked>> | 86% | 57,769 psi | 89% | 2858 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 84% | 57,943 psi | 89% | 2877 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 94% | 57,696 psi | 89% | 2959 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 88% | 55,579 psi | 86% | 2936 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 98% | 57,377 psi | 88% | 2933 fps | 98.3% |
| Alliant Reloder-22ᴾ | <<locked>> | 100% | 54,650 psi | 84% | 2940 fps | 98% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 51,938 psi | 80% | 2877 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 45,614 psi | 70% | 2808 fps | 99.1% |
| Alliant Reloder-26 | <<locked>> | 98% | 55,521 psi | 85% | 3015 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 82% | 58,798 psi | 90% | 2890 fps | 100% |
| Bofors RP15ᴾ | <<locked>> | 100% | 50,357 psi | 77% | 2864 fps | 97% |
| Bofors RP3 | <<locked>> | 84% | 55,709 psi | 86% | 2831 fps | 100% |
| Bofors RP5ᴾ | <<locked>> | 100% | 54,650 psi | 84% | 2940 fps | 98% |
| Bofors RP7 | <<locked>> | 90% | 57,870 psi | 89% | 2854 fps | 99% |
| Hodgdon H380 | <<locked>> | 84% | 55,564 psi | 85% | 2838 fps | 99.9% |
| Hodgdon H414 | <<locked>> | 90% | 55,927 psi | 86% | 2904 fps | 99.2% |
| Hodgdon H4350 | <<locked>> | 88% | 55,608 psi | 86% | 2861 fps | 98.2% |
| Hodgdon H4831 | <<locked>> | 98% | 55,854 psi | 86% | 2884 fps | 96% |
| Hodgdon H4831 SCᴾ | <<locked>> | 100% | 58,262 psi | 90% | 2920 fps | 96.5% |
| Hodgdon Hybrid 100V | <<locked>> | 96% | 58,276 psi | 90% | 2881 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 82% | 56,376 psi | 87% | 2871 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 44,585 psi | 69% | 2828 fps | 96.1% |
| Hodgdon Superformance | <<locked>> | 90% | 55,927 psi | 86% | 2940 fps | 99% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,825 psi | 57% | 1762 fps | 100% |
| Hodgdon VARGET | <<locked>> | 82% | 57,072 psi | 88% | 2835 fps | 100% |
| IMR 4064 | <<locked>> | 84% | 56,072 psi | 86% | 2812 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 84% | 58,581 psi | 90% | 2844 fps | 99.3% |
| IMR 4350 | <<locked>> | 94% | 58,465 psi | 90% | 2884 fps | 99.1% |
| IMR 4451 Enduron | <<locked>> | 88% | 55,782 psi | 86% | 2828 fps | 99% |
| IMR 4831 | <<locked>> | 94% | 57,914 psi | 89% | 2897 fps | 100% |
| IMR 4895 | <<locked>> | 82% | 55,912 psi | 86% | 2854 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 98% | 57,508 psi | 88% | 2871 fps | 96.6% |
| IMR 7828 SSCᴾ | <<locked>> | 100% | 53,345 psi | 82% | 2913 fps | 96.3% |
| Lovex S060 | <<locked>> | 82% | 57,566 psi | 89% | 2795 fps | 100% |
| Lovex S062 | <<locked>> | 84% | 56,710 psi | 87% | 2808 fps | 100% |
| Lovex S065 | <<locked>> | 90% | 56,260 psi | 87% | 2828 fps | 99.7% |
| Lovex S070 | <<locked>> | 92% | 57,595 psi | 89% | 2874 fps | 99.4% |
| Lovex S071ᴾ | <<locked>> | 100% | 46,978 psi | 72% | 2723 fps | 98.6% |
| Norma 201 | <<locked>> | 82% | 58,102 psi | 89% | 2818 fps | 100% |
| Norma 202 | <<locked>> | 82% | 58,624 psi | 90% | 2812 fps | 100% |
| Norma 203B | <<locked>> | 84% | 57,246 psi | 88% | 2864 fps | 100% |
| Norma 204 | <<locked>> | 92% | 55,680 psi | 86% | 2884 fps | 97.8% |
| Norma MRPᴾ | <<locked>> | 100% | 58,131 psi | 89% | 3025 fps | 99.4% |
| Norma URP | <<locked>> | 92% | 56,115 psi | 86% | 2890 fps | 100% |
| Ramshot Big Game | <<locked>> | 84% | 57,798 psi | 89% | 2887 fps | 100% |
| Ramshot Grandᴾ | <<locked>> | 100% | 53,679 psi | 83% | 2927 fps | 96.7% |
| Ramshot Hunter | <<locked>> | 94% | 58,218 psi | 90% | 2943 fps | 99.8% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 48,167 psi | 74% | 2805 fps | 97.3% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,608 psi | 58% | 1804 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 84% | 55,187 psi | 85% | 2818 fps | 99.3% |
| ReloadSwiss RS 60 | <<locked>> | 86% | 54,940 psi | 85% | 2923 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 92% | 57,363 psi | 88% | 2933 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 92% | 55,564 psi | 85% | 2956 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 44,469 psi | 68% | 2822 fps | 97.3% |
| Rottweil R 902 | <<locked>> | 82% | 55,492 psi | 85% | 2772 fps | 100% |
| Rottweil R 903 | <<locked>> | 86% | 55,506 psi | 85% | 2822 fps | 100% |
| Rottweil R 904 | <<locked>> | 96% | 56,275 psi | 87% | 2861 fps | 96.9% |
| Rottweil R 905 | <<locked>> | 98% | 56,652 psi | 87% | 2920 fps | 98.3% |
| Rottweil R 907 | <<locked>> | 90% | 57,870 psi | 89% | 2854 fps | 99% |
| Shooters World Long Rifle | <<locked>> | 90% | 56,260 psi | 87% | 2828 fps | 99.7% |
| Shooters World Precision | <<locked>> | 84% | 56,710 psi | 87% | 2808 fps | 100% |
| Shooters World SW4350 | <<locked>> | 92% | 57,595 psi | 89% | 2874 fps | 99.4% |
| SNPE Vectan SP 11 | <<locked>> | 86% | 56,492 psi | 87% | 2874 fps | 100% |
| SNPE Vectan SP 9 | <<locked>> | 82% | 57,421 psi | 88% | 2844 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 82% | 58,392 psi | 90% | 2743 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 86% | 55,898 psi | 86% | 2700 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 90% | 55,912 psi | 86% | 2779 fps | 99.1% |
| SNPE Vectan Tubal 8000 | <<locked>> | 98% | 56,144 psi | 86% | 2917 fps | 98.2% |
| Somchem S335 | <<locked>> | 82% | 58,291 psi | 90% | 2743 fps | 100% |
| Somchem S355 | <<locked>> | 86% | 55,434 psi | 85% | 2818 fps | 100% |
| Somchem S361 | <<locked>> | 96% | 58,073 psi | 89% | 2851 fps | 96.4% |
| Somchem S365 | <<locked>> | 94% | 55,419 psi | 85% | 2897 fps | 100% |
| Somchem S385 | <<locked>> | 98% | 57,653 psi | 89% | 2900 fps | 99% |
| Vihtavuori N133 | <<locked>> | 82% | 58,784 psi | 90% | 2723 fps | 100% |
| Vihtavuori N135 | <<locked>> | 82% | 55,680 psi | 86% | 2733 fps | 100% |
| Vihtavuori N140 | <<locked>> | 82% | 55,753 psi | 86% | 2746 fps | 100% |
| Vihtavuori N150 | <<locked>> | 88% | 56,333 psi | 87% | 2785 fps | 100% |
| Vihtavuori N160 | <<locked>> | 92% | 58,146 psi | 89% | 2884 fps | 100% |
| Vihtavuori N165ᴾ | <<locked>> | 100% | 53,258 psi | 82% | 2818 fps | 98% |
| Vihtavuori N540 | <<locked>> | 84% | 57,319 psi | 88% | 2792 fps | 100% |
| Vihtavuori N550 | <<locked>> | 92% | 57,421 psi | 88% | 2894 fps | 100% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 58,305 psi | 90% | 2956 fps | 100% |
| Vihtavuori N560ᴾ | <<locked>> | 100% | 58,320 psi | 90% | 3009 fps | 96.9% |
| Winchester 6.5 StaBALL | <<locked>> | 92% | 57,551 psi | 89% | 2851 fps | 100% |
| Winchester 760 | <<locked>> | 90% | 56,173 psi | 86% | 2907 fps | 99.2% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 47,210 psi | 73% | 2940 fps | 100% |
| Winchester StaBALL Match | <<locked>> | 82% | 57,783 psi | 89% | 2858 fps | 100% |
| Winchester Supreme 780ᴾ | <<locked>> | 100% | 57,682 psi | 89% | 2894 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% | 54,723 psi | 84% | 2717 fps | 100% |
| Accurate 2700 | <<locked>> | 80% | 50,807 psi | 78% | 2707 fps | 97.7% |
| Accurate 3100 | <<locked>> | 84% | 33,910 psi | 52% | 2451 fps | 95% |
| Accurate 4064 | <<locked>> | 80% | 51,779 psi | 80% | 2723 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 39,639 psi | 61% | 2595 fps | 98.4% |
| Accurate MAGPRO | <<locked>> | 98% | 53,417 psi | 82% | 2933 fps | 95.2% |
| ADI AR 2208 | <<locked>> | 80% | 47,442 psi | 73% | 2680 fps | 99.8% |
| ADI AR 2209 | <<locked>> | 90% | 45,295 psi | 70% | 2723 fps | 95.6% |
| ADI AR 2213 | <<locked>> | 96% | 49,052 psi | 75% | 2818 fps | 95% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 51,967 psi | 80% | 2890 fps | 100% |
| Alliant Power Pro Varmint | <<locked>> | 90% | 45,484 psi | 70% | 2726 fps | 95.7% |
| Alliant Power Pro Varmint | <<locked>> | 90% | 45,484 psi | 70% | 2726 fps | 95.7% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 48,254 psi | 74% | 2710 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 51,358 psi | 79% | 2776 fps | 100% |
| Alliant Reloder-16 | 46.7 gr | 80% | 37,971 psi | 58% | 2595 fps | 98.4% |
| Alliant Reloder-17 | <<locked>> | 80% | 42,786 psi | 66% | 2717 fps | 99.9% |
| Alliant Reloder-19 | <<locked>> | 90% | 44,976 psi | 69% | 2717 fps | 95.6% |
| Alliant Reloder-22 | <<locked>> | 92% | 42,627 psi | 66% | 2717 fps | 95.1% |
| Alliant Reloder-23 | <<locked>> | 80% | 28,776 psi | 44% | 2375 fps | 96.6% |
| Alliant Reloder-25 | <<locked>> | 90% | 33,968 psi | 52% | 2530 fps | 95.4% |
| Alliant Reloder-26 | 52.8 gr | 82% | 32,547 psi | 50% | 2536 fps | 95.8% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 55,463 psi | 85% | 2841 fps | 100% |
| Bofors RP15 | <<locked>> | 96% | 44,730 psi | 69% | 2756 fps | 95.6% |
| Bofors RP3 | <<locked>> | 80% | 49,023 psi | 75% | 2726 fps | 100% |
| Bofors RP5 | <<locked>> | 92% | 42,627 psi | 66% | 2717 fps | 95.1% |
| Bofors RP7 | <<locked>> | 80% | 43,047 psi | 66% | 2595 fps | 96.2% |
| Hodgdon H380 | <<locked>> | 80% | 49,197 psi | 76% | 2736 fps | 99.5% |
| Hodgdon H414 | <<locked>> | 80% | 40,959 psi | 63% | 2631 fps | 96.3% |
| Hodgdon H4350 | <<locked>> | 80% | 43,482 psi | 67% | 2641 fps | 95.6% |
| Hodgdon H4831 | <<locked>> | 96% | 52,446 psi | 81% | 2828 fps | 95.3% |
| Hodgdon H4831 SC | <<locked>> | 96% | 51,329 psi | 79% | 2808 fps | 95% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 35,810 psi | 55% | 2497 fps | 99% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 52,794 psi | 81% | 2815 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 98% | 42,032 psi | 65% | 2769 fps | 95.1% |
| Hodgdon Superformance | <<locked>> | 80% | 39,697 psi | 61% | 2635 fps | 95.4% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,528 psi | 42% | 1572 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 53,693 psi | 83% | 2782 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 49,879 psi | 77% | 2713 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 80% | 52,011 psi | 80% | 2740 fps | 98.6% |
| IMR 4350 | <<locked>> | 82% | 40,857 psi | 63% | 2572 fps | 95.6% |
| IMR 4451 Enduron | <<locked>> | 80% | 43,976 psi | 68% | 2618 fps | 96.9% |
| IMR 4831 | <<locked>> | 80% | 37,884 psi | 58% | 2546 fps | 98.1% |
| IMR 4895 | <<locked>> | 80% | 52,605 psi | 81% | 2802 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 94% | 51,039 psi | 79% | 2766 fps | 95.2% |
| IMR 7828 SSC | <<locked>> | 98% | 49,908 psi | 77% | 2848 fps | 95.4% |
| Lovex S060 | <<locked>> | 80% | 54,244 psi | 83% | 2746 fps | 100% |
| Lovex S062 | <<locked>> | 80% | 50,546 psi | 78% | 2717 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 42,235 psi | 65% | 2582 fps | 97.9% |
| Lovex S070 | <<locked>> | 80% | 40,567 psi | 62% | 2566 fps | 96.4% |
| Lovex S071 | <<locked>> | 90% | 35,114 psi | 54% | 2480 fps | 95.5% |
| Norma 201 | <<locked>> | 80% | 55,027 psi | 85% | 2776 fps | 100% |
| Norma 202 | <<locked>> | 80% | 55,172 psi | 85% | 2766 fps | 100% |
| Norma 203B | <<locked>> | 80% | 50,749 psi | 78% | 2762 fps | 100% |
| Norma 204 | <<locked>> | 86% | 45,977 psi | 71% | 2713 fps | 95.7% |
| Norma MRP | <<locked>> | 88% | 39,378 psi | 61% | 2674 fps | 95.6% |
| Norma URP | <<locked>> | 80% | 38,943 psi | 60% | 2585 fps | 98.2% |
| Ramshot Big Game | <<locked>> | 80% | 50,734 psi | 78% | 2782 fps | 100% |
| Ramshot Grand | <<locked>> | 98% | 50,024 psi | 77% | 2861 fps | 95.8% |
| Ramshot Hunter | <<locked>> | 80% | 37,695 psi | 58% | 2569 fps | 96.2% |
| Ramshot Magnum | <<locked>> | 96% | 42,192 psi | 65% | 2687 fps | 95.5% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,297 psi | 44% | 1614 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 48,747 psi | 75% | 2710 fps | 98.5% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 45,252 psi | 70% | 2769 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 38,914 psi | 60% | 2605 fps | 98% |
| ReloadSwiss RS 70 | 51 gr | 80% | 37,536 psi | 58% | 2608 fps | 97.3% |
| ReloadSwiss RS 76 | <<locked>> | 96% | 39,247 psi | 60% | 2700 fps | 95.2% |
| Rottweil R 902 | <<locked>> | 80% | 52,504 psi | 81% | 2730 fps | 100% |
| Rottweil R 903 | <<locked>> | 80% | 46,427 psi | 71% | 2677 fps | 100% |
| Rottweil R 904 | <<locked>> | 92% | 49,821 psi | 77% | 2753 fps | 95.5% |
| Rottweil R 905 | <<locked>> | 90% | 44,237 psi | 68% | 2703 fps | 95.6% |
| Rottweil R 907 | <<locked>> | 80% | 43,047 psi | 66% | 2595 fps | 96.2% |
| Shooters World Long Rifle | <<locked>> | 80% | 42,235 psi | 65% | 2582 fps | 97.9% |
| Shooters World Precision | <<locked>> | 80% | 50,546 psi | 78% | 2717 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 40,567 psi | 62% | 2566 fps | 96.4% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 46,862 psi | 72% | 2723 fps | 99.9% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 54,114 psi | 83% | 2795 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 55,201 psi | 85% | 2700 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 46,934 psi | 72% | 2572 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 41,307 psi | 64% | 2523 fps | 96.4% |
| SNPE Vectan Tubal 8000 | <<locked>> | 90% | 43,816 psi | 67% | 2700 fps | 95.5% |
| Somchem S335 | <<locked>> | 80% | 55,245 psi | 85% | 2700 fps | 100% |
| Somchem S355 | <<locked>> | 80% | 46,499 psi | 72% | 2671 fps | 100% |
| Somchem S361 | <<locked>> | 92% | 51,300 psi | 79% | 2746 fps | 95% |
| Somchem S365 | <<locked>> | 80% | 35,607 psi | 55% | 2549 fps | 99.7% |
| Somchem S385 | <<locked>> | 86% | 40,059 psi | 62% | 2589 fps | 95.3% |
| Vihtavuori N133 | <<locked>> | 80% | 55,564 psi | 85% | 2680 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 52,605 psi | 81% | 2690 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 52,489 psi | 81% | 2700 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 44,353 psi | 68% | 2602 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 40,161 psi | 62% | 2579 fps | 98.4% |
| Vihtavuori N165 | <<locked>> | 92% | 41,495 psi | 64% | 2612 fps | 95.3% |
| Vihtavuori N540 | <<locked>> | 80% | 50,952 psi | 78% | 2700 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 39,929 psi | 61% | 2585 fps | 98.2% |
| Vihtavuori N555 | <<locked>> | 80% | 31,749 psi | 49% | 2454 fps | 96.8% |
| Vihtavuori N560 | <<locked>> | 96% | 51,271 psi | 79% | 2894 fps | 95.4% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 39,189 psi | 60% | 2549 fps | 99.7% |
| Winchester 760 | <<locked>> | 80% | 40,959 psi | 63% | 2631 fps | 96.3% |
| Winchester StaBALL HD | <<locked>> | 80% | 25,802 psi | 40% | 2352 fps | 95.4% |
| Winchester StaBALL Match | <<locked>> | 80% | 54,099 psi | 83% | 2802 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 92% | 44,367 psi | 68% | 2671 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 100 powders for .280 Ackley Improved loaded with the .284 | 150gr | Barnes X BT. Norma MRP delivers the highest muzzle velocity at 3,025 fps; across all powders the maximum-charge window runs from 1,762 fps to 3,025 fps. Accurate 3100 gives the best case fill at 100 %, and 100 of the 100 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (448 MPa), the top charges use 57–90 %, leaving at least 10 % headroom. The 150.0 gr projectile in 0.284" calls for a 1:10.5 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. Alliant Reloder-26, ReloadSwiss RS 70, Alliant Reloder-16 rank at the top here: for .280 Ackley Improved with the .284 | 150gr | Barnes X BT 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.