Load Specifications
Load data in caliber .280 Ackley Improved with .284 | 174gr | Prvi Partizan FMJ BT bullet and 89 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Norma MRP, Vihtavuori N560 and Accurate MAGPRO.
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 2700 | <<locked>> | 82% | 56,971 psi | 88% | 2641 fps | 99.7% |
| Accurate 3100 | <<locked>> | 98% | 56,333 psi | 87% | 2700 fps | 100% |
| Accurate 4064 | <<locked>> | 82% | 56,985 psi | 88% | 2618 fps | 100% |
| Accurate 4350 | <<locked>> | 90% | 58,175 psi | 89% | 2736 fps | 100% |
| Accurate MAGPRO | <<locked>> | 98% | 58,479 psi | 90% | 2848 fps | 98.1% |
| ADI AR 2208 | <<locked>> | 84% | 56,492 psi | 87% | 2651 fps | 100% |
| ADI AR 2209 | <<locked>> | 96% | 58,755 psi | 90% | 2789 fps | 99.5% |
| ADI AR 2213 | <<locked>> | 98% | 56,347 psi | 87% | 2789 fps | 98.6% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 43,990 psi | 68% | 2572 fps | 96.1% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 38,957 psi | 60% | 2533 fps | 97.9% |
| Alliant Reloder- TS 15.5 | <<locked>> | 84% | 57,421 psi | 88% | 2667 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 82% | 57,798 psi | 89% | 2694 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 90% | 55,245 psi | 85% | 2736 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 86% | 56,304 psi | 87% | 2753 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 96% | 58,305 psi | 90% | 2779 fps | 99.5% |
| Alliant Reloder-22 | <<locked>> | 98% | 55,840 psi | 86% | 2782 fps | 99.4% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 56,855 psi | 87% | 2759 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 49,139 psi | 76% | 2713 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 96% | 57,130 psi | 88% | 2848 fps | 100% |
| Baschieri & Pellagri 109ᴾ | <<locked>> | 100% | 58,726 psi | 90% | 2753 fps | 96.2% |
| Bofors RP15ᴾ | <<locked>> | 100% | 54,679 psi | 84% | 2766 fps | 99.2% |
| Bofors RP3 | <<locked>> | 84% | 58,566 psi | 90% | 2687 fps | 100% |
| Bofors RP30ᴾ | <<locked>> | 100% | 45,005 psi | 69% | 2641 fps | 97.1% |
| Bofors RP5 | <<locked>> | 98% | 55,840 psi | 86% | 2782 fps | 99.4% |
| Bofors RP7 | <<locked>> | 88% | 57,551 psi | 89% | 2684 fps | 99.8% |
| Hodgdon H1000ᴾ | <<locked>> | 100% | 48,544 psi | 75% | 2661 fps | 98% |
| Hodgdon H380 | <<locked>> | 82% | 54,969 psi | 85% | 2657 fps | 100% |
| Hodgdon H414 | <<locked>> | 88% | 56,376 psi | 87% | 2740 fps | 99.9% |
| Hodgdon H4350 | <<locked>> | 86% | 55,912 psi | 86% | 2700 fps | 99.4% |
| Hodgdon H4831 | <<locked>> | 96% | 56,652 psi | 87% | 2733 fps | 98% |
| Hodgdon H4831 SC | <<locked>> | 96% | 55,434 psi | 85% | 2717 fps | 97.8% |
| Hodgdon Hybrid 100V | <<locked>> | 92% | 55,535 psi | 85% | 2664 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 48,022 psi | 74% | 2759 fps | 99.1% |
| Hodgdon Superformance | <<locked>> | 88% | 56,594 psi | 87% | 2776 fps | 99.9% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,709 psi | 56% | 1647 fps | 100% |
| IMR 4064 | <<locked>> | 82% | 55,927 psi | 86% | 2631 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 82% | 58,378 psi | 90% | 2674 fps | 99.9% |
| IMR 4350 | <<locked>> | 92% | 58,726 psi | 90% | 2720 fps | 99.9% |
| IMR 4451 Enduron | <<locked>> | 86% | 55,753 psi | 86% | 2661 fps | 99.8% |
| IMR 4831 | <<locked>> | 92% | 58,508 psi | 90% | 2726 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 96% | 57,754 psi | 89% | 2717 fps | 98.3% |
| IMR 7828 SSCᴾ | <<locked>> | 100% | 57,928 psi | 89% | 2825 fps | 98.9% |
| Lovex S062 | <<locked>> | 82% | 56,260 psi | 87% | 2625 fps | 100% |
| Lovex S065 | <<locked>> | 88% | 55,898 psi | 86% | 2657 fps | 100% |
| Lovex S070 | <<locked>> | 90% | 57,392 psi | 88% | 2700 fps | 100% |
| Lovex S071ᴾ | <<locked>> | 100% | 50,125 psi | 77% | 2615 fps | 99.8% |
| Norma 203B | <<locked>> | 82% | 57,087 psi | 88% | 2680 fps | 100% |
| Norma 204 | <<locked>> | 90% | 56,144 psi | 86% | 2726 fps | 99.2% |
| Norma MRP | <<locked>> | 96% | 55,680 psi | 86% | 2808 fps | 99.9% |
| Norma URP | <<locked>> | 90% | 56,521 psi | 87% | 2720 fps | 100% |
| Ramshot Big Game | <<locked>> | 82% | 57,914 psi | 89% | 2707 fps | 100% |
| Ramshot Grandᴾ | <<locked>> | 100% | 58,610 psi | 90% | 2844 fps | 99.2% |
| Ramshot Hunter | <<locked>> | 90% | 55,361 psi | 85% | 2726 fps | 100% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 52,634 psi | 81% | 2726 fps | 99.5% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,478 psi | 58% | 1686 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 84% | 58,421 psi | 90% | 2697 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 84% | 56,028 psi | 86% | 2743 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 90% | 58,001 psi | 89% | 2759 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 90% | 56,376 psi | 87% | 2789 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 48,138 psi | 74% | 2756 fps | 99.7% |
| Rottweil R 902 | <<locked>> | 82% | 58,204 psi | 90% | 2635 fps | 100% |
| Rottweil R 903 | <<locked>> | 86% | 58,726 psi | 90% | 2687 fps | 100% |
| Rottweil R 904 | <<locked>> | 94% | 56,565 psi | 87% | 2703 fps | 98.6% |
| Rottweil R 905 | <<locked>> | 96% | 57,624 psi | 89% | 2766 fps | 99.5% |
| Rottweil R 907 | <<locked>> | 88% | 57,551 psi | 89% | 2684 fps | 99.8% |
| Shooters World Long Rifle | <<locked>> | 88% | 55,898 psi | 86% | 2657 fps | 100% |
| Shooters World Precision | <<locked>> | 82% | 56,260 psi | 87% | 2625 fps | 100% |
| Shooters World SW4350 | <<locked>> | 90% | 57,392 psi | 88% | 2700 fps | 100% |
| SNPE Vectan SP 11 | <<locked>> | 84% | 56,521 psi | 87% | 2694 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 84% | 55,550 psi | 85% | 2520 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 88% | 55,376 psi | 85% | 2615 fps | 99.8% |
| SNPE Vectan Tubal 8000 | <<locked>> | 96% | 57,159 psi | 88% | 2759 fps | 99.5% |
| Somchem S355 | <<locked>> | 86% | 58,581 psi | 90% | 2680 fps | 100% |
| Somchem S361 | <<locked>> | 94% | 58,479 psi | 90% | 2703 fps | 98.2% |
| Somchem S365 | <<locked>> | 92% | 56,405 psi | 87% | 2720 fps | 100% |
| Somchem S385 | <<locked>> | 96% | 58,204 psi | 90% | 2740 fps | 99.8% |
| Vihtavuori N140 | <<locked>> | 82% | 58,697 psi | 90% | 2605 fps | 100% |
| Vihtavuori N150 | <<locked>> | 86% | 56,130 psi | 86% | 2608 fps | 100% |
| Vihtavuori N160 | <<locked>> | 90% | 58,581 psi | 90% | 2710 fps | 100% |
| Vihtavuori N165ᴾ | <<locked>> | 100% | 57,624 psi | 89% | 2720 fps | 99.7% |
| Vihtavuori N540 | <<locked>> | 82% | 56,739 psi | 87% | 2602 fps | 100% |
| Vihtavuori N550 | <<locked>> | 90% | 57,653 psi | 89% | 2717 fps | 100% |
| Vihtavuori N555 | <<locked>> | 96% | 55,593 psi | 86% | 2733 fps | 100% |
| Vihtavuori N560 | <<locked>> | 96% | 55,724 psi | 86% | 2802 fps | 98.2% |
| Vihtavuori N565ᴾ | <<locked>> | 100% | 51,169 psi | 79% | 2720 fps | 97.6% |
| Winchester 6.5 StaBALL | <<locked>> | 90% | 58,233 psi | 90% | 2677 fps | 100% |
| Winchester 760 | <<locked>> | 88% | 56,637 psi | 87% | 2740 fps | 99.9% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 53,243 psi | 82% | 2835 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 98% | 58,247 psi | 90% | 2736 fps | 99.4% |
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 2700 | <<locked>> | 80% | 53,548 psi | 82% | 2595 fps | 99.4% |
| Accurate 3100 | <<locked>> | 80% | 30,835 psi | 47% | 2241 fps | 95.8% |
| Accurate 4064 | <<locked>> | 80% | 53,577 psi | 82% | 2572 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 41,655 psi | 64% | 2480 fps | 99.7% |
| Accurate MAGPRO | 59.4 gr | 92% | 47,529 psi | 73% | 2671 fps | 95.9% |
| ADI AR 2208 | <<locked>> | 80% | 49,893 psi | 77% | 2556 fps | 100% |
| ADI AR 2209 | <<locked>> | 82% | 37,318 psi | 57% | 2411 fps | 95.2% |
| ADI AR 2213 | <<locked>> | 90% | 43,250 psi | 67% | 2562 fps | 95.7% |
| ADI AR 2217 | <<locked>> | 98% | 41,205 psi | 63% | 2516 fps | 95.1% |
| ADI AR 2225 | <<locked>> | 96% | 34,403 psi | 53% | 2421 fps | 96% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 50,966 psi | 78% | 2579 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 54,331 psi | 84% | 2648 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 80% | 40,074 psi | 62% | 2487 fps | 99.8% |
| Alliant Reloder-17 | <<locked>> | 80% | 45,687 psi | 70% | 2598 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 82% | 37,260 psi | 57% | 2408 fps | 95.3% |
| Alliant Reloder-22 | <<locked>> | 86% | 37,608 psi | 58% | 2457 fps | 95.6% |
| Alliant Reloder-23 | <<locked>> | 80% | 29,617 psi | 46% | 2270 fps | 98.8% |
| Alliant Reloder-25 | <<locked>> | 84% | 29,472 psi | 45% | 2280 fps | 95.7% |
| Alliant Reloder-26 | <<locked>> | 80% | 31,836 psi | 49% | 2385 fps | 97.7% |
| Baschieri & Pellagri 109 | <<locked>> | 98% | 55,172 psi | 85% | 2697 fps | 95.4% |
| Bofors RP15 | <<locked>> | 88% | 37,130 psi | 57% | 2448 fps | 95.2% |
| Bofors RP3 | <<locked>> | 80% | 51,547 psi | 79% | 2592 fps | 100% |
| Bofors RP30 | <<locked>> | 96% | 39,494 psi | 61% | 2533 fps | 95.4% |
| Bofors RP5 | <<locked>> | 86% | 37,608 psi | 58% | 2457 fps | 95.6% |
| Bofors RP7 | <<locked>> | 80% | 45,034 psi | 69% | 2487 fps | 98.4% |
| Hodgdon H1000 | <<locked>> | 94% | 39,610 psi | 61% | 2484 fps | 95.3% |
| Hodgdon H380 | <<locked>> | 80% | 51,634 psi | 79% | 2608 fps | 100% |
| Hodgdon H414 | <<locked>> | 80% | 43,279 psi | 67% | 2523 fps | 98.5% |
| Hodgdon H4350 | <<locked>> | 80% | 46,108 psi | 71% | 2539 fps | 98% |
| Hodgdon H4831 | <<locked>> | 88% | 43,192 psi | 66% | 2513 fps | 95% |
| Hodgdon H4831 SC | <<locked>> | 90% | 45,324 psi | 70% | 2552 fps | 95.6% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 37,739 psi | 58% | 2382 fps | 99.9% |
| Hodgdon Retumbo | <<locked>> | 92% | 37,057 psi | 57% | 2520 fps | 95.9% |
| Hodgdon Superformance | <<locked>> | 80% | 42,163 psi | 65% | 2539 fps | 98.1% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,659 psi | 43% | 1473 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 52,489 psi | 81% | 2585 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 80% | 54,621 psi | 84% | 2621 fps | 99.8% |
| IMR 4350 | <<locked>> | 80% | 40,524 psi | 62% | 2421 fps | 97.4% |
| IMR 4451 Enduron | <<locked>> | 80% | 46,369 psi | 71% | 2510 fps | 98.9% |
| IMR 4831 | <<locked>> | 80% | 39,639 psi | 61% | 2431 fps | 99.6% |
| IMR 4955 Enduron | <<locked>> | 86% | 42,395 psi | 65% | 2461 fps | 95% |
| IMR 7828 SSC | <<locked>> | 90% | 41,539 psi | 64% | 2543 fps | 95.2% |
| Lovex S062 | <<locked>> | 80% | 52,852 psi | 81% | 2579 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 43,888 psi | 68% | 2464 fps | 99.4% |
| Lovex S070 | <<locked>> | 80% | 42,090 psi | 65% | 2451 fps | 98.4% |
| Lovex S071 | <<locked>> | 84% | 30,153 psi | 46% | 2224 fps | 95.5% |
| Norma 203B | <<locked>> | 80% | 53,693 psi | 83% | 2635 fps | 100% |
| Norma 204 | <<locked>> | 80% | 40,045 psi | 62% | 2448 fps | 96% |
| Norma MRP | 51.9 gr | 82% | 34,171 psi | 53% | 2408 fps | 95.8% |
| Norma URP | <<locked>> | 80% | 40,959 psi | 63% | 2470 fps | 99.6% |
| Ramshot Big Game | <<locked>> | 80% | 54,157 psi | 83% | 2657 fps | 100% |
| Ramshot Grand | <<locked>> | 90% | 41,046 psi | 63% | 2546 fps | 95.5% |
| Ramshot Hunter | <<locked>> | 80% | 39,740 psi | 61% | 2461 fps | 98.5% |
| Ramshot Magnum | <<locked>> | 90% | 36,434 psi | 56% | 2428 fps | 95.9% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,195 psi | 43% | 1509 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 51,430 psi | 79% | 2595 fps | 99.8% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 48,486 psi | 75% | 2641 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 41,379 psi | 64% | 2500 fps | 99.6% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 39,682 psi | 61% | 2510 fps | 99.3% |
| ReloadSwiss RS 76 | <<locked>> | 90% | 33,997 psi | 52% | 2441 fps | 95.7% |
| Rottweil R 902 | <<locked>> | 80% | 54,694 psi | 84% | 2589 fps | 100% |
| Rottweil R 903 | <<locked>> | 80% | 48,501 psi | 75% | 2543 fps | 100% |
| Rottweil R 904 | <<locked>> | 84% | 41,408 psi | 64% | 2448 fps | 95.3% |
| Rottweil R 905 | <<locked>> | 82% | 36,376 psi | 56% | 2392 fps | 95.2% |
| Rottweil R 907 | <<locked>> | 80% | 45,034 psi | 69% | 2487 fps | 98.4% |
| Shooters World Long Rifle | <<locked>> | 80% | 43,888 psi | 68% | 2464 fps | 99.4% |
| Shooters World Precision | <<locked>> | 80% | 52,852 psi | 81% | 2579 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 42,090 psi | 65% | 2451 fps | 98.4% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 49,632 psi | 76% | 2595 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 49,197 psi | 76% | 2438 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 43,004 psi | 66% | 2415 fps | 98.4% |
| SNPE Vectan Tubal 8000 | <<locked>> | 82% | 36,085 psi | 56% | 2385 fps | 95.1% |
| Somchem S355 | <<locked>> | 80% | 48,602 psi | 75% | 2539 fps | 100% |
| Somchem S361 | <<locked>> | 86% | 44,933 psi | 69% | 2490 fps | 95.5% |
| Somchem S365 | <<locked>> | 80% | 37,724 psi | 58% | 2431 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 34,679 psi | 53% | 2326 fps | 95.5% |
| Vihtavuori N140 | <<locked>> | 80% | 55,201 psi | 85% | 2559 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 46,383 psi | 71% | 2470 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 42,554 psi | 65% | 2470 fps | 99.8% |
| Vihtavuori N165 | <<locked>> | 86% | 36,448 psi | 56% | 2362 fps | 95.7% |
| Vihtavuori N540 | <<locked>> | 80% | 53,388 psi | 82% | 2559 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 41,785 psi | 64% | 2467 fps | 99.6% |
| Vihtavuori N555 | <<locked>> | 80% | 33,069 psi | 51% | 2339 fps | 98.7% |
| Vihtavuori N560 | 55.7 gr | 88% | 42,380 psi | 65% | 2572 fps | 95.1% |
| Vihtavuori N565 | <<locked>> | 94% | 41,858 psi | 64% | 2552 fps | 95.2% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 41,220 psi | 63% | 2431 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 43,482 psi | 67% | 2526 fps | 98.6% |
| Winchester StaBALL HD | <<locked>> | 80% | 26,150 psi | 40% | 2264 fps | 98.5% |
| Winchester Supreme 780 | <<locked>> | 86% | 38,696 psi | 60% | 2415 fps | 95.8% |
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 94 powders for .280 Ackley Improved loaded with the .284 | 174gr | Prvi Partizan FMJ BT. Accurate MAGPRO delivers the highest muzzle velocity at 2,848 fps; across all powders the maximum-charge window runs from 1,647 fps to 2,848 fps. ADI AR 2217 gives the best case fill at 100 %, and 94 of the 94 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 174.0 gr projectile in 0.284" calls for a 1:12.0 twist; slower twists will usually not stabilise this weight. ADI AR 2217, ADI AR 2225, Alliant Reloder-23 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. Norma MRP, Vihtavuori N560, Accurate MAGPRO rank at the top here: for .280 Ackley Improved with the .284 | 174gr | Prvi Partizan FMJ BT they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, IMR 8133 Enduron, ReloadSwiss RS 80, Vihtavuori N170 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.