Load Specifications
Load data in caliber .280 Ackley Improved with .284 | 175gr | Speer Magnum Tip Soft Point bullet and 89 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 Alliant Reloder-26.
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 2700 | <<locked>> | 82% | 57,522 psi | 88% | 2644 fps | 99.7% |
| Accurate 3100 | <<locked>> | 98% | 56,956 psi | 88% | 2703 fps | 100% |
| Accurate 4064 | <<locked>> | 82% | 57,363 psi | 88% | 2615 fps | 100% |
| Accurate 4350 | <<locked>> | 88% | 55,114 psi | 85% | 2687 fps | 100% |
| Accurate MAGPRO | <<locked>> | 96% | 55,405 psi | 85% | 2795 fps | 97.7% |
| ADI AR 2208 | <<locked>> | 84% | 56,768 psi | 87% | 2651 fps | 100% |
| ADI AR 2209 | <<locked>> | 94% | 55,666 psi | 86% | 2736 fps | 99.3% |
| ADI AR 2213 | <<locked>> | 98% | 56,971 psi | 88% | 2792 fps | 98.7% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 44,440 psi | 68% | 2575 fps | 96.4% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 39,363 psi | 61% | 2539 fps | 98.1% |
| Alliant Power Pro Varmint | <<locked>> | 94% | 55,796 psi | 86% | 2733 fps | 99.3% |
| Alliant Power Pro Varmint | <<locked>> | 94% | 55,796 psi | 86% | 2733 fps | 99.3% |
| Alliant Reloder- TS 15.5 | <<locked>> | 84% | 58,073 psi | 89% | 2671 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 82% | 58,117 psi | 89% | 2694 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 90% | 55,883 psi | 86% | 2740 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 86% | 57,014 psi | 88% | 2753 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 94% | 55,071 psi | 85% | 2726 fps | 99.3% |
| Alliant Reloder-22 | <<locked>> | 98% | 56,463 psi | 87% | 2789 fps | 99.5% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 57,522 psi | 88% | 2759 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 49,748 psi | 77% | 2717 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 96% | 58,175 psi | 89% | 2854 fps | 100% |
| Bofors RP15ᴾ | <<locked>> | 100% | 55,332 psi | 85% | 2769 fps | 99.3% |
| Bofors RP3 | <<locked>> | 82% | 55,593 psi | 86% | 2644 fps | 100% |
| Bofors RP30ᴾ | <<locked>> | 100% | 45,542 psi | 70% | 2648 fps | 97.3% |
| Bofors RP5 | <<locked>> | 98% | 56,463 psi | 87% | 2789 fps | 99.5% |
| Bofors RP7 | <<locked>> | 88% | 58,102 psi | 89% | 2687 fps | 99.8% |
| Hodgdon H1000ᴾ | <<locked>> | 100% | 49,023 psi | 75% | 2664 fps | 98.2% |
| Hodgdon H380 | <<locked>> | 82% | 55,608 psi | 86% | 2661 fps | 100% |
| Hodgdon H414 | <<locked>> | 88% | 56,956 psi | 88% | 2740 fps | 99.9% |
| Hodgdon H4350 | <<locked>> | 86% | 56,173 psi | 86% | 2697 fps | 99.5% |
| Hodgdon H4831 | <<locked>> | 96% | 57,232 psi | 88% | 2740 fps | 98.2% |
| Hodgdon H4831 SC | <<locked>> | 96% | 55,999 psi | 86% | 2720 fps | 98% |
| Hodgdon Hybrid 100V | <<locked>> | 92% | 56,144 psi | 86% | 2664 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 48,544 psi | 75% | 2762 fps | 99.3% |
| Hodgdon Superformance | <<locked>> | 88% | 57,232 psi | 88% | 2779 fps | 99.9% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,970 psi | 57% | 1650 fps | 100% |
| IMR 4064 | <<locked>> | 82% | 56,507 psi | 87% | 2635 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 82% | 58,653 psi | 90% | 2671 fps | 100% |
| IMR 4350 | <<locked>> | 90% | 55,796 psi | 86% | 2674 fps | 99.7% |
| IMR 4451 Enduron | <<locked>> | 86% | 55,985 psi | 86% | 2661 fps | 99.9% |
| IMR 4831 | <<locked>> | 90% | 55,288 psi | 85% | 2677 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 96% | 58,262 psi | 90% | 2717 fps | 98.5% |
| IMR 7828 SSCᴾ | <<locked>> | 100% | 58,552 psi | 90% | 2828 fps | 99% |
| Lovex S062 | <<locked>> | 82% | 56,869 psi | 87% | 2628 fps | 100% |
| Lovex S065 | <<locked>> | 88% | 56,449 psi | 87% | 2657 fps | 100% |
| Lovex S070 | <<locked>> | 90% | 58,015 psi | 89% | 2703 fps | 100% |
| Lovex S071ᴾ | <<locked>> | 100% | 50,749 psi | 78% | 2618 fps | 99.9% |
| Norma 203B | <<locked>> | 82% | 57,435 psi | 88% | 2677 fps | 100% |
| Norma 204 | <<locked>> | 90% | 56,724 psi | 87% | 2730 fps | 99.3% |
| Norma MRP | <<locked>> | 96% | 56,318 psi | 87% | 2812 fps | 100% |
| Norma URP | <<locked>> | 90% | 57,159 psi | 88% | 2720 fps | 100% |
| Ramshot Big Game | <<locked>> | 82% | 58,537 psi | 90% | 2710 fps | 100% |
| Ramshot Grand | <<locked>> | 98% | 55,303 psi | 85% | 2792 fps | 98.9% |
| Ramshot Hunter | <<locked>> | 90% | 55,941 psi | 86% | 2726 fps | 100% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 53,214 psi | 82% | 2726 fps | 99.6% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,753 psi | 58% | 1690 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 82% | 55,259 psi | 85% | 2648 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 84% | 56,434 psi | 87% | 2740 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 90% | 58,639 psi | 90% | 2759 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 90% | 57,014 psi | 88% | 2792 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 48,631 psi | 75% | 2759 fps | 99.8% |
| Rottweil R 902 | <<locked>> | 82% | 58,494 psi | 90% | 2631 fps | 100% |
| Rottweil R 903 | <<locked>> | 84% | 55,724 psi | 86% | 2641 fps | 100% |
| Rottweil R 904 | <<locked>> | 94% | 57,145 psi | 88% | 2707 fps | 98.7% |
| Rottweil R 905 | <<locked>> | 96% | 58,204 psi | 90% | 2766 fps | 99.6% |
| Rottweil R 907 | <<locked>> | 88% | 58,102 psi | 89% | 2687 fps | 99.8% |
| Shooters World Long Rifle | <<locked>> | 88% | 56,449 psi | 87% | 2657 fps | 100% |
| Shooters World Precision | <<locked>> | 82% | 56,869 psi | 87% | 2628 fps | 100% |
| Shooters World SW4350 | <<locked>> | 90% | 58,015 psi | 89% | 2703 fps | 100% |
| SNPE Vectan SP 11 | <<locked>> | 84% | 57,116 psi | 88% | 2697 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 84% | 56,173 psi | 86% | 2523 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 88% | 55,941 psi | 86% | 2618 fps | 99.9% |
| SNPE Vectan Tubal 8000 | <<locked>> | 96% | 57,754 psi | 89% | 2762 fps | 99.6% |
| Somchem S355 | <<locked>> | 84% | 55,390 psi | 85% | 2635 fps | 100% |
| Somchem S361 | <<locked>> | 92% | 55,245 psi | 85% | 2654 fps | 97.8% |
| Somchem S365 | <<locked>> | 92% | 57,087 psi | 88% | 2720 fps | 100% |
| Somchem S385 | <<locked>> | 96% | 58,798 psi | 90% | 2740 fps | 99.9% |
| Vihtavuori N150 | <<locked>> | 86% | 56,710 psi | 87% | 2608 fps | 100% |
| Vihtavuori N160 | <<locked>> | 88% | 55,564 psi | 85% | 2664 fps | 100% |
| Vihtavuori N165ᴾ | <<locked>> | 100% | 58,189 psi | 90% | 2720 fps | 99.7% |
| Vihtavuori N540 | <<locked>> | 82% | 57,348 psi | 88% | 2605 fps | 100% |
| Vihtavuori N550 | <<locked>> | 90% | 58,247 psi | 90% | 2720 fps | 100% |
| Vihtavuori N555 | <<locked>> | 96% | 56,275 psi | 87% | 2736 fps | 100% |
| Vihtavuori N560 | <<locked>> | 96% | 56,333 psi | 87% | 2805 fps | 98.4% |
| Vihtavuori N565ᴾ | <<locked>> | 100% | 52,069 psi | 80% | 2726 fps | 97.9% |
| Winchester 6.5 StaBALL | <<locked>> | 90% | 58,813 psi | 90% | 2677 fps | 100% |
| Winchester 760 | <<locked>> | 88% | 56,956 psi | 88% | 2740 fps | 99.9% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 53,983 psi | 83% | 2838 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 96% | 55,071 psi | 85% | 2687 fps | 99.2% |
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 2700 | <<locked>> | 80% | 53,824 psi | 83% | 2592 fps | 99.5% |
| Accurate 3100 | <<locked>> | 80% | 31,111 psi | 48% | 2244 fps | 96.1% |
| Accurate 4064 | <<locked>> | 80% | 53,896 psi | 83% | 2572 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 41,989 psi | 65% | 2480 fps | 99.8% |
| Accurate MAGPRO | <<locked>> | 90% | 44,860 psi | 69% | 2618 fps | 95.2% |
| ADI AR 2208 | <<locked>> | 80% | 50,444 psi | 78% | 2559 fps | 100% |
| ADI AR 2209 | <<locked>> | 82% | 37,565 psi | 58% | 2411 fps | 95.4% |
| ADI AR 2213 | <<locked>> | 88% | 40,988 psi | 63% | 2510 fps | 95% |
| ADI AR 2217 | <<locked>> | 98% | 41,640 psi | 64% | 2520 fps | 95.4% |
| ADI AR 2225 | <<locked>> | 94% | 32,735 psi | 50% | 2372 fps | 95.3% |
| Alliant Power Pro Varmint | <<locked>> | 82% | 37,869 psi | 58% | 2415 fps | 95.6% |
| Alliant Power Pro Varmint | <<locked>> | 82% | 37,869 psi | 58% | 2415 fps | 95.6% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 51,271 psi | 79% | 2579 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 54,650 psi | 84% | 2644 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 80% | 40,350 psi | 62% | 2487 fps | 99.8% |
| Alliant Reloder-17 | <<locked>> | 80% | 46,296 psi | 71% | 2602 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 82% | 37,521 psi | 58% | 2411 fps | 95.5% |
| Alliant Reloder-22 | <<locked>> | 86% | 37,884 psi | 58% | 2461 fps | 95.8% |
| Alliant Reloder-23 | <<locked>> | 80% | 29,892 psi | 46% | 2270 fps | 98.9% |
| Alliant Reloder-25 | <<locked>> | 84% | 29,849 psi | 46% | 2287 fps | 96% |
| Alliant Reloder-26 | 52.5 gr | 80% | 32,271 psi | 50% | 2388 fps | 97.9% |
| Bofors RP15 | <<locked>> | 88% | 37,594 psi | 58% | 2451 fps | 95.5% |
| Bofors RP3 | <<locked>> | 80% | 51,895 psi | 80% | 2592 fps | 100% |
| Bofors RP30 | <<locked>> | 96% | 39,987 psi | 62% | 2536 fps | 95.7% |
| Bofors RP5 | <<locked>> | 86% | 37,884 psi | 58% | 2461 fps | 95.8% |
| Bofors RP7 | <<locked>> | 80% | 45,324 psi | 70% | 2487 fps | 98.5% |
| Hodgdon H1000 | <<locked>> | 94% | 40,059 psi | 62% | 2490 fps | 95.6% |
| Hodgdon H380 | <<locked>> | 80% | 52,199 psi | 80% | 2612 fps | 100% |
| Hodgdon H414 | <<locked>> | 80% | 43,801 psi | 67% | 2526 fps | 98.7% |
| Hodgdon H4350 | <<locked>> | 80% | 46,412 psi | 71% | 2539 fps | 98.2% |
| Hodgdon H4831 | <<locked>> | 88% | 43,656 psi | 67% | 2516 fps | 95.3% |
| Hodgdon H4831 SC | <<locked>> | 88% | 42,975 psi | 66% | 2503 fps | 95.1% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 38,072 psi | 59% | 2385 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 90% | 35,215 psi | 54% | 2467 fps | 95.1% |
| Hodgdon Superformance | <<locked>> | 80% | 42,714 psi | 66% | 2543 fps | 98.3% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,499 psi | 42% | 1467 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 53,098 psi | 82% | 2589 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 80% | 55,201 psi | 85% | 2625 fps | 99.8% |
| IMR 4350 | <<locked>> | 80% | 40,799 psi | 63% | 2421 fps | 97.6% |
| IMR 4451 Enduron | <<locked>> | 80% | 46,630 psi | 72% | 2510 fps | 99% |
| IMR 4831 | <<locked>> | 80% | 40,176 psi | 62% | 2434 fps | 99.7% |
| IMR 4955 Enduron | <<locked>> | 86% | 42,859 psi | 66% | 2464 fps | 95.2% |
| IMR 7828 SSC | <<locked>> | 90% | 41,800 psi | 64% | 2543 fps | 95.5% |
| Lovex S062 | <<locked>> | 80% | 53,461 psi | 82% | 2579 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 44,164 psi | 68% | 2464 fps | 99.5% |
| Lovex S070 | <<locked>> | 80% | 42,598 psi | 66% | 2457 fps | 98.6% |
| Lovex S071 | <<locked>> | 84% | 30,618 psi | 47% | 2231 fps | 95.8% |
| Norma 203B | <<locked>> | 80% | 53,983 psi | 83% | 2631 fps | 100% |
| Norma 204 | <<locked>> | 80% | 40,524 psi | 62% | 2454 fps | 96.3% |
| Norma MRP | 50.9 gr | 80% | 32,314 psi | 50% | 2356 fps | 95.1% |
| Norma URP | <<locked>> | 80% | 41,510 psi | 64% | 2474 fps | 99.7% |
| Ramshot Big Game | <<locked>> | 80% | 54,766 psi | 84% | 2657 fps | 100% |
| Ramshot Grand | <<locked>> | 90% | 41,510 psi | 64% | 2549 fps | 95.8% |
| Ramshot Hunter | <<locked>> | 80% | 40,234 psi | 62% | 2467 fps | 98.6% |
| Ramshot Magnum | <<locked>> | 88% | 34,534 psi | 53% | 2379 fps | 95.3% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,253 psi | 43% | 1509 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 51,982 psi | 80% | 2598 fps | 99.8% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 49,139 psi | 76% | 2641 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 41,698 psi | 64% | 2500 fps | 99.7% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 40,176 psi | 62% | 2513 fps | 99.5% |
| ReloadSwiss RS 76 | <<locked>> | 90% | 34,403 psi | 53% | 2448 fps | 96.1% |
| Rottweil R 902 | <<locked>> | 80% | 55,013 psi | 85% | 2585 fps | 100% |
| Rottweil R 903 | <<locked>> | 80% | 49,110 psi | 76% | 2546 fps | 100% |
| Rottweil R 904 | <<locked>> | 84% | 41,669 psi | 64% | 2448 fps | 95.5% |
| Rottweil R 905 | <<locked>> | 82% | 36,680 psi | 56% | 2395 fps | 95.4% |
| Rottweil R 907 | <<locked>> | 80% | 45,324 psi | 70% | 2487 fps | 98.5% |
| Shooters World Long Rifle | <<locked>> | 80% | 44,164 psi | 68% | 2464 fps | 99.5% |
| Shooters World Precision | <<locked>> | 80% | 53,461 psi | 82% | 2579 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 42,598 psi | 66% | 2457 fps | 98.6% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 50,212 psi | 77% | 2598 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 49,472 psi | 76% | 2434 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 43,294 psi | 67% | 2418 fps | 98.6% |
| SNPE Vectan Tubal 8000 | <<locked>> | 82% | 36,376 psi | 56% | 2388 fps | 95.3% |
| Somchem S355 | <<locked>> | 80% | 48,907 psi | 75% | 2539 fps | 100% |
| Somchem S361 | <<locked>> | 86% | 45,368 psi | 70% | 2493 fps | 95.7% |
| Somchem S365 | <<locked>> | 80% | 38,087 psi | 59% | 2431 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 34,954 psi | 54% | 2329 fps | 95.7% |
| Vihtavuori N150 | <<locked>> | 80% | 46,934 psi | 72% | 2474 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 42,830 psi | 66% | 2467 fps | 99.8% |
| Vihtavuori N165 | <<locked>> | 84% | 34,403 psi | 53% | 2313 fps | 95.1% |
| Vihtavuori N540 | <<locked>> | 80% | 53,969 psi | 83% | 2559 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 42,322 psi | 65% | 2474 fps | 99.7% |
| Vihtavuori N555 | <<locked>> | 80% | 33,388 psi | 51% | 2339 fps | 98.9% |
| Vihtavuori N560 | 56 gr | 88% | 42,888 psi | 66% | 2575 fps | 95.3% |
| Vihtavuori N565 | <<locked>> | 94% | 42,395 psi | 65% | 2559 fps | 95.5% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 41,698 psi | 64% | 2434 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 43,801 psi | 67% | 2526 fps | 98.7% |
| Winchester StaBALL HD | <<locked>> | 80% | 26,513 psi | 41% | 2274 fps | 98.8% |
| Winchester Supreme 780 | <<locked>> | 84% | 36,477 psi | 56% | 2362 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 89 powders for .280 Ackley Improved loaded with the .284 | 175gr | Speer Magnum Tip Soft Point. Alliant Reloder-26 delivers the highest muzzle velocity at 2,854 fps; across all powders the maximum-charge window runs from 1,650 fps to 2,854 fps. ADI AR 2217 gives the best case fill at 100 %, and 89 of the 89 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 1:12.5 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. Vihtavuori N560, Norma MRP, Alliant Reloder-26 rank at the top here: for .280 Ackley Improved with the .284 | 175gr | Speer Magnum Tip Soft Point 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.