Load Specifications
Load data in caliber .280 Ackley Improved with .284 | 175gr | A-Square MONO RN bullet and 81 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Vihtavuori N560, Norma MRP 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 3100 | <<locked>> | 96% | 56,666 psi | 87% | 2713 fps | 100% |
| Accurate 4350 | <<locked>> | 88% | 58,465 psi | 90% | 2746 fps | 100% |
| Accurate MAGPRO | <<locked>> | 94% | 55,027 psi | 85% | 2802 fps | 97.9% |
| ADI AR 2208 | <<locked>> | 82% | 55,825 psi | 86% | 2651 fps | 100% |
| ADI AR 2209 | <<locked>> | 92% | 55,230 psi | 85% | 2746 fps | 99.4% |
| ADI AR 2213 | <<locked>> | 96% | 56,637 psi | 87% | 2805 fps | 99% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 47,369 psi | 73% | 2648 fps | 97.6% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 41,989 psi | 65% | 2612 fps | 99.1% |
| Alliant Reloder- TS 15.5 | <<locked>> | 82% | 57,145 psi | 88% | 2674 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 88% | 55,492 psi | 85% | 2746 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 84% | 56,492 psi | 87% | 2759 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 94% | 58,320 psi | 90% | 2789 fps | 99.7% |
| Alliant Reloder-22 | <<locked>> | 96% | 56,492 psi | 87% | 2802 fps | 99.6% |
| Alliant Reloder-23 | <<locked>> | 98% | 57,464 psi | 88% | 2769 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 52,982 psi | 82% | 2776 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 94% | 58,262 psi | 90% | 2861 fps | 100% |
| Baschieri & Pellagri 109 | <<locked>> | 98% | 58,378 psi | 90% | 2766 fps | 96.8% |
| Bofors RP15 | <<locked>> | 98% | 55,332 psi | 85% | 2782 fps | 99.5% |
| Bofors RP3 | <<locked>> | 82% | 58,436 psi | 90% | 2694 fps | 100% |
| Bofors RP30ᴾ | <<locked>> | 100% | 49,110 psi | 76% | 2720 fps | 98.3% |
| Bofors RP5 | <<locked>> | 96% | 56,492 psi | 87% | 2802 fps | 99.6% |
| Bofors RP7 | <<locked>> | 86% | 57,319 psi | 88% | 2694 fps | 99.9% |
| Hodgdon H1000ᴾ | <<locked>> | 100% | 52,112 psi | 80% | 2733 fps | 99% |
| Hodgdon H380 | <<locked>> | 82% | 58,233 psi | 90% | 2713 fps | 100% |
| Hodgdon H414 | <<locked>> | 86% | 56,231 psi | 87% | 2746 fps | 100% |
| Hodgdon H4350 | <<locked>> | 84% | 55,564 psi | 85% | 2703 fps | 99.6% |
| Hodgdon H4831 | <<locked>> | 94% | 56,739 psi | 87% | 2746 fps | 98.4% |
| Hodgdon H4831 SC | <<locked>> | 94% | 55,564 psi | 85% | 2733 fps | 98.3% |
| Hodgdon Hybrid 100V | <<locked>> | 90% | 55,840 psi | 86% | 2674 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 51,895 psi | 80% | 2838 fps | 99.8% |
| Hodgdon Superformance | <<locked>> | 86% | 56,724 psi | 87% | 2785 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,057 psi | 57% | 1670 fps | 100% |
| IMR 4064 | <<locked>> | 82% | 58,769 psi | 90% | 2680 fps | 100% |
| IMR 4350 | <<locked>> | 90% | 58,566 psi | 90% | 2730 fps | 99.9% |
| IMR 4451 Enduron | <<locked>> | 86% | 58,624 psi | 90% | 2713 fps | 100% |
| IMR 4831 | <<locked>> | 90% | 58,653 psi | 90% | 2736 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 94% | 57,740 psi | 89% | 2730 fps | 98.7% |
| IMR 7828 SSC | <<locked>> | 98% | 58,276 psi | 90% | 2841 fps | 99.2% |
| Lovex S065 | <<locked>> | 86% | 55,825 psi | 86% | 2664 fps | 100% |
| Lovex S070 | <<locked>> | 88% | 57,174 psi | 88% | 2707 fps | 100% |
| Lovex S071ᴾ | <<locked>> | 100% | 54,056 psi | 83% | 2677 fps | 100% |
| Norma 204 | <<locked>> | 88% | 55,985 psi | 86% | 2733 fps | 99.4% |
| Norma 217ᴾ | <<locked>> | 100% | 37,623 psi | 58% | 2539 fps | 97.4% |
| Norma MRP | <<locked>> | 94% | 56,405 psi | 87% | 2825 fps | 100% |
| Norma URP | <<locked>> | 88% | 56,507 psi | 87% | 2726 fps | 100% |
| Ramshot Grand | <<locked>> | 96% | 55,071 psi | 85% | 2805 fps | 99.1% |
| Ramshot Hunter | <<locked>> | 88% | 55,434 psi | 85% | 2733 fps | 100% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 57,334 psi | 88% | 2799 fps | 99.9% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,826 psi | 58% | 1709 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 82% | 57,943 psi | 89% | 2700 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 82% | 56,159 psi | 86% | 2746 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 88% | 58,378 psi | 90% | 2769 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 88% | 56,681 psi | 87% | 2799 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 52,475 psi | 81% | 2838 fps | 100% |
| ReloadSwiss RS 80ᴾ | <<locked>> | 100% | 47,166 psi | 73% | 2723 fps | 96.5% |
| Rottweil R 903 | <<locked>> | 84% | 58,624 psi | 90% | 2690 fps | 100% |
| Rottweil R 904 | <<locked>> | 92% | 56,608 psi | 87% | 2720 fps | 98.9% |
| Rottweil R 905 | <<locked>> | 94% | 58,015 psi | 89% | 2779 fps | 99.7% |
| Rottweil R 907 | <<locked>> | 86% | 57,319 psi | 88% | 2694 fps | 99.9% |
| Shooters World Long Rifle | <<locked>> | 86% | 55,825 psi | 86% | 2664 fps | 100% |
| Shooters World SW4350 | <<locked>> | 88% | 57,174 psi | 88% | 2707 fps | 100% |
| SNPE Vectan SP 11 | <<locked>> | 82% | 56,318 psi | 87% | 2700 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 84% | 58,305 psi | 90% | 2562 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 88% | 58,711 psi | 90% | 2674 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 94% | 57,551 psi | 89% | 2776 fps | 99.7% |
| Somchem S355 | <<locked>> | 84% | 58,160 psi | 89% | 2684 fps | 100% |
| Somchem S361 | <<locked>> | 92% | 58,204 psi | 90% | 2713 fps | 98.6% |
| Somchem S365 | <<locked>> | 90% | 56,855 psi | 87% | 2726 fps | 100% |
| Somchem S385 | <<locked>> | 94% | 58,450 psi | 90% | 2753 fps | 99.9% |
| Vihtavuori N150 | <<locked>> | 84% | 55,869 psi | 86% | 2612 fps | 100% |
| Vihtavuori N160 | <<locked>> | 88% | 58,668 psi | 90% | 2720 fps | 100% |
| Vihtavuori N165 | <<locked>> | 98% | 57,885 psi | 89% | 2733 fps | 99.8% |
| Vihtavuori N550 | <<locked>> | 88% | 57,653 psi | 89% | 2726 fps | 100% |
| Vihtavuori N555 | <<locked>> | 94% | 56,188 psi | 86% | 2746 fps | 100% |
| Vihtavuori N560 | <<locked>> | 94% | 56,304 psi | 87% | 2818 fps | 98.6% |
| Vihtavuori N565ᴾ | <<locked>> | 100% | 55,593 psi | 86% | 2795 fps | 98.7% |
| Vihtavuori N568ᴾ | <<locked>> | 100% | 48,573 psi | 75% | 2730 fps | 96.2% |
| Winchester 6.5 StaBALL | <<locked>> | 88% | 58,131 psi | 89% | 2684 fps | 100% |
| Winchester 760 | <<locked>> | 86% | 56,550 psi | 87% | 2749 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 98% | 54,911 psi | 84% | 2851 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 96% | 58,436 psi | 90% | 2749 fps | 99.7% |
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 3100 | <<locked>> | 80% | 33,170 psi | 51% | 2300 fps | 97.1% |
| Accurate 4350 | <<locked>> | 80% | 44,585 psi | 69% | 2539 fps | 100% |
| Accurate MAGPRO | 60.2 gr | 88% | 44,628 psi | 69% | 2625 fps | 95.5% |
| ADI AR 2208 | <<locked>> | 80% | 52,634 psi | 81% | 2605 fps | 100% |
| ADI AR 2209 | <<locked>> | 80% | 37,188 psi | 57% | 2418 fps | 95.7% |
| ADI AR 2213 | <<locked>> | 86% | 40,582 psi | 62% | 2520 fps | 95.3% |
| ADI AR 2217 | <<locked>> | 96% | 41,408 psi | 64% | 2533 fps | 95.9% |
| ADI AR 2225 | <<locked>> | 92% | 32,692 psi | 50% | 2385 fps | 95.8% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 53,867 psi | 83% | 2631 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 80% | 42,801 psi | 66% | 2546 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 80% | 49,124 psi | 76% | 2654 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 37,231 psi | 57% | 2415 fps | 95.8% |
| Alliant Reloder-22 | <<locked>> | 82% | 35,418 psi | 54% | 2415 fps | 95.2% |
| Alliant Reloder-23 | <<locked>> | 80% | 31,879 psi | 49% | 2329 fps | 99.5% |
| Alliant Reloder-25 | <<locked>> | 80% | 27,775 psi | 43% | 2234 fps | 95.2% |
| Alliant Reloder-26 | <<locked>> | 80% | 34,606 psi | 53% | 2454 fps | 98.9% |
| Baschieri & Pellagri 109 | <<locked>> | 94% | 51,677 psi | 80% | 2657 fps | 95.2% |
| Bofors RP15 | <<locked>> | 86% | 37,608 psi | 58% | 2461 fps | 95.9% |
| Bofors RP3 | <<locked>> | 80% | 54,781 psi | 84% | 2644 fps | 100% |
| Bofors RP30 | <<locked>> | 92% | 37,420 psi | 58% | 2490 fps | 95.1% |
| Bofors RP5 | <<locked>> | 82% | 35,418 psi | 54% | 2415 fps | 95.2% |
| Bofors RP7 | <<locked>> | 80% | 47,572 psi | 73% | 2543 fps | 99.1% |
| Hodgdon H1000 | <<locked>> | 90% | 37,217 psi | 57% | 2444 fps | 95% |
| Hodgdon H380 | <<locked>> | 80% | 54,636 psi | 84% | 2661 fps | 100% |
| Hodgdon H414 | <<locked>> | 80% | 46,340 psi | 71% | 2585 fps | 99.3% |
| Hodgdon H4350 | <<locked>> | 80% | 48,907 psi | 75% | 2598 fps | 98.8% |
| Hodgdon H4831 | <<locked>> | 86% | 43,236 psi | 67% | 2523 fps | 95.5% |
| Hodgdon H4831 SC | <<locked>> | 86% | 42,540 psi | 65% | 2510 fps | 95.3% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 40,292 psi | 62% | 2434 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 88% | 35,186 psi | 54% | 2480 fps | 95.6% |
| Hodgdon Superformance | <<locked>> | 80% | 45,498 psi | 70% | 2605 fps | 99% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,847 psi | 43% | 1493 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 55,419 psi | 85% | 2635 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 42,873 psi | 66% | 2477 fps | 98.3% |
| IMR 4451 Enduron | <<locked>> | 80% | 48,834 psi | 75% | 2566 fps | 99.5% |
| IMR 4831 | <<locked>> | 80% | 42,525 psi | 65% | 2490 fps | 99.9% |
| IMR 4955 Enduron | <<locked>> | 84% | 42,337 psi | 65% | 2470 fps | 95.5% |
| IMR 7828 SSC | <<locked>> | 88% | 41,597 psi | 64% | 2552 fps | 95.8% |
| Lovex S065 | <<locked>> | 80% | 46,412 psi | 71% | 2520 fps | 99.8% |
| Lovex S070 | <<locked>> | 80% | 44,817 psi | 69% | 2510 fps | 99.2% |
| Lovex S071 | <<locked>> | 80% | 28,631 psi | 44% | 2185 fps | 95.2% |
| Norma 204 | <<locked>> | 80% | 42,815 psi | 66% | 2513 fps | 97.2% |
| Norma 217 | <<locked>> | 96% | 33,112 psi | 51% | 2428 fps | 95.5% |
| Norma MRP | 53.8 gr | 80% | 34,563 psi | 53% | 2421 fps | 96.4% |
| Norma URP | <<locked>> | 80% | 43,903 psi | 68% | 2526 fps | 99.9% |
| Ramshot Grand | <<locked>> | 86% | 38,537 psi | 59% | 2500 fps | 95.1% |
| Ramshot Hunter | <<locked>> | 80% | 42,612 psi | 66% | 2523 fps | 99.2% |
| Ramshot Magnum | <<locked>> | 86% | 34,214 psi | 53% | 2385 fps | 95.6% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,384 psi | 44% | 1529 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 54,447 psi | 84% | 2654 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 52,170 psi | 80% | 2694 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 44,483 psi | 68% | 2559 fps | 99.9% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 42,685 psi | 66% | 2575 fps | 99.8% |
| ReloadSwiss RS 76 | <<locked>> | 86% | 31,995 psi | 49% | 2395 fps | 95.2% |
| ReloadSwiss RS 80 | <<locked>> | 98% | 44,019 psi | 68% | 2661 fps | 95.5% |
| Rottweil R 903 | <<locked>> | 80% | 51,692 psi | 80% | 2598 fps | 100% |
| Rottweil R 904 | <<locked>> | 82% | 41,321 psi | 64% | 2457 fps | 95.8% |
| Rottweil R 905 | <<locked>> | 80% | 36,506 psi | 56% | 2402 fps | 95.7% |
| Rottweil R 907 | <<locked>> | 80% | 47,572 psi | 73% | 2543 fps | 99.1% |
| Shooters World Long Rifle | <<locked>> | 80% | 46,412 psi | 71% | 2520 fps | 99.8% |
| Shooters World SW4350 | <<locked>> | 80% | 44,817 psi | 69% | 2510 fps | 99.2% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 52,866 psi | 81% | 2651 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 51,750 psi | 80% | 2480 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 45,310 psi | 70% | 2467 fps | 99.1% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 36,172 psi | 56% | 2395 fps | 95.6% |
| Somchem S355 | <<locked>> | 80% | 51,445 psi | 79% | 2592 fps | 100% |
| Somchem S361 | <<locked>> | 82% | 41,829 psi | 64% | 2444 fps | 95.1% |
| Somchem S365 | <<locked>> | 80% | 40,611 psi | 62% | 2487 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 37,173 psi | 57% | 2388 fps | 96.8% |
| Vihtavuori N150 | <<locked>> | 80% | 49,342 psi | 76% | 2523 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 45,208 psi | 70% | 2523 fps | 100% |
| Vihtavuori N165 | <<locked>> | 82% | 34,287 psi | 53% | 2320 fps | 95.4% |
| Vihtavuori N550 | <<locked>> | 80% | 44,498 psi | 68% | 2523 fps | 99.9% |
| Vihtavuori N555 | <<locked>> | 80% | 35,737 psi | 55% | 2398 fps | 99.5% |
| Vihtavuori N560 | 57.8 gr | 86% | 42,757 psi | 66% | 2585 fps | 95.7% |
| Vihtavuori N565 | <<locked>> | 90% | 39,711 psi | 61% | 2513 fps | 95% |
| Vihtavuori N568 | <<locked>> | 98% | 45,397 psi | 70% | 2671 fps | 95.3% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 44,106 psi | 68% | 2487 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 46,340 psi | 71% | 2585 fps | 99.3% |
| Winchester StaBALL HD | <<locked>> | 80% | 28,268 psi | 43% | 2339 fps | 99.6% |
| Winchester Supreme 780 | <<locked>> | 82% | 36,187 psi | 56% | 2369 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 86 powders for .280 Ackley Improved loaded with the .284 | 175gr | A-Square MONO RN. Alliant Reloder-26 delivers the highest muzzle velocity at 2,861 fps; across all powders the maximum-charge window runs from 1,670 fps to 2,861 fps. ADI AR 2217 gives the best case fill at 100 %, and 86 of the 86 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 175.0 gr projectile in 0.284" calls for a 1:16.5 twist; slower twists will usually not stabilise this weight. ADI AR 2217, ADI AR 2225, Alliant Reloder-25 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. Vihtavuori N560, Norma MRP, Accurate MAGPRO rank at the top here: for .280 Ackley Improved with the .284 | 175gr | A-Square MONO RN they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, Alliant Reloder-33, IMR 7977 Enduron, IMR 8133 Enduron 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.