Load Specifications
Load data in caliber .280 Ackley Improved with .284 | 180gr | Sierra MatchKing bullet and 91 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Alliant Reloder-26, Norma MRP and Vihtavuori N560.
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% | 56,420 psi | 87% | 2579 fps | 99.7% |
| Accurate 3100 | <<locked>> | 98% | 55,158 psi | 85% | 2631 fps | 100% |
| Accurate 4064 | <<locked>> | 82% | 56,318 psi | 87% | 2552 fps | 100% |
| Accurate 4350 | <<locked>> | 90% | 57,116 psi | 88% | 2667 fps | 100% |
| Accurate MAGPRO | <<locked>> | 98% | 57,406 psi | 88% | 2776 fps | 98.1% |
| ADI AR 2208 | <<locked>> | 84% | 55,666 psi | 86% | 2585 fps | 100% |
| ADI AR 2209 | <<locked>> | 96% | 57,783 psi | 89% | 2717 fps | 99.5% |
| ADI AR 2213 | <<locked>> | 98% | 55,376 psi | 85% | 2720 fps | 98.5% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 43,207 psi | 66% | 2507 fps | 96% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 38,290 psi | 59% | 2470 fps | 97.8% |
| Alliant Reloder- TS 15.5 | <<locked>> | 84% | 56,942 psi | 88% | 2608 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 82% | 56,971 psi | 88% | 2628 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 92% | 57,827 psi | 89% | 2717 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 86% | 55,579 psi | 86% | 2687 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 96% | 57,130 psi | 88% | 2703 fps | 99.5% |
| Alliant Reloder-22ᴾ | <<locked>> | 100% | 58,639 psi | 90% | 2769 fps | 99.7% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 55,637 psi | 86% | 2690 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 48,008 psi | 74% | 2641 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 96% | 55,840 psi | 86% | 2779 fps | 100% |
| Baschieri & Pellagri 109ᴾ | <<locked>> | 100% | 57,798 psi | 89% | 2684 fps | 96.1% |
| Bofors RP15ᴾ | <<locked>> | 100% | 53,621 psi | 82% | 2697 fps | 99.2% |
| Bofors RP3 | <<locked>> | 84% | 57,856 psi | 89% | 2625 fps | 100% |
| Bofors RP30ᴾ | <<locked>> | 100% | 44,106 psi | 68% | 2575 fps | 97% |
| Bofors RP5ᴾ | <<locked>> | 100% | 58,639 psi | 90% | 2769 fps | 99.7% |
| Bofors RP7 | <<locked>> | 88% | 56,739 psi | 87% | 2618 fps | 99.8% |
| Hodgdon H1000ᴾ | <<locked>> | 100% | 47,500 psi | 73% | 2589 fps | 97.8% |
| Hodgdon H380 | <<locked>> | 84% | 57,957 psi | 89% | 2641 fps | 100% |
| Hodgdon H414 | <<locked>> | 88% | 55,419 psi | 85% | 2667 fps | 99.9% |
| Hodgdon H4350 | <<locked>> | 88% | 58,450 psi | 90% | 2677 fps | 99.7% |
| Hodgdon H4831 | <<locked>> | 96% | 55,579 psi | 86% | 2664 fps | 98% |
| Hodgdon H4831 SC | <<locked>> | 98% | 58,146 psi | 89% | 2700 fps | 98.3% |
| Hodgdon Hybrid 100V | <<locked>> | 94% | 58,291 psi | 90% | 2641 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 47,166 psi | 73% | 2690 fps | 99.1% |
| Hodgdon Superformance | <<locked>> | 88% | 55,434 psi | 85% | 2703 fps | 99.8% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,796 psi | 57% | 1604 fps | 100% |
| IMR 4064 | <<locked>> | 84% | 58,682 psi | 90% | 2612 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 82% | 57,682 psi | 89% | 2605 fps | 99.9% |
| IMR 4350 | <<locked>> | 92% | 57,943 psi | 89% | 2654 fps | 99.8% |
| IMR 4451 Enduron | <<locked>> | 88% | 58,494 psi | 90% | 2641 fps | 99.9% |
| IMR 4831 | <<locked>> | 92% | 57,609 psi | 89% | 2661 fps | 100% |
| IMR 4895 | <<locked>> | 82% | 58,465 psi | 90% | 2651 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 96% | 56,884 psi | 88% | 2648 fps | 98.3% |
| IMR 7828 SSCᴾ | <<locked>> | 100% | 56,681 psi | 87% | 2749 fps | 98.8% |
| Lovex S062 | <<locked>> | 82% | 55,579 psi | 86% | 2559 fps | 100% |
| Lovex S065 | <<locked>> | 90% | 58,682 psi | 90% | 2638 fps | 100% |
| Lovex S070 | <<locked>> | 90% | 56,739 psi | 87% | 2635 fps | 100% |
| Lovex S071ᴾ | <<locked>> | 100% | 49,153 psi | 76% | 2549 fps | 99.8% |
| Norma 203B | <<locked>> | 82% | 56,275 psi | 87% | 2615 fps | 100% |
| Norma 204 | <<locked>> | 90% | 55,376 psi | 85% | 2657 fps | 99.2% |
| Norma MRP | <<locked>> | 98% | 58,537 psi | 90% | 2795 fps | 100% |
| Norma URP | <<locked>> | 90% | 55,767 psi | 86% | 2651 fps | 100% |
| Ramshot Big Game | <<locked>> | 82% | 57,101 psi | 88% | 2641 fps | 100% |
| Ramshot Grandᴾ | <<locked>> | 100% | 57,508 psi | 88% | 2772 fps | 99.1% |
| Ramshot Hunter | <<locked>> | 92% | 58,262 psi | 90% | 2710 fps | 100% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 51,387 psi | 79% | 2654 fps | 99.4% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,594 psi | 58% | 1644 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 84% | 57,682 psi | 89% | 2631 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 84% | 54,810 psi | 84% | 2674 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 90% | 56,898 psi | 88% | 2687 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 90% | 55,434 psi | 85% | 2720 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 47,137 psi | 73% | 2687 fps | 99.7% |
| Rottweil R 902 | <<locked>> | 82% | 57,508 psi | 88% | 2569 fps | 100% |
| Rottweil R 903 | <<locked>> | 86% | 58,059 psi | 89% | 2621 fps | 100% |
| Rottweil R 904 | <<locked>> | 94% | 55,854 psi | 86% | 2638 fps | 98.6% |
| Rottweil R 905 | <<locked>> | 96% | 56,594 psi | 87% | 2697 fps | 99.5% |
| Rottweil R 907 | <<locked>> | 88% | 56,739 psi | 87% | 2618 fps | 99.8% |
| Shooters World Long Rifle | <<locked>> | 90% | 58,682 psi | 90% | 2638 fps | 100% |
| Shooters World Precision | <<locked>> | 82% | 55,579 psi | 86% | 2559 fps | 100% |
| Shooters World SW4350 | <<locked>> | 90% | 56,739 psi | 87% | 2635 fps | 100% |
| SNPE Vectan SP 11 | <<locked>> | 84% | 55,666 psi | 86% | 2628 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 86% | 58,334 psi | 90% | 2500 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 90% | 58,421 psi | 90% | 2598 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 96% | 56,130 psi | 86% | 2690 fps | 99.4% |
| Somchem S355 | <<locked>> | 86% | 57,566 psi | 89% | 2612 fps | 100% |
| Somchem S361 | <<locked>> | 94% | 57,363 psi | 88% | 2635 fps | 98.1% |
| Somchem S365 | <<locked>> | 92% | 55,390 psi | 85% | 2651 fps | 100% |
| Somchem S385 | <<locked>> | 96% | 57,101 psi | 88% | 2671 fps | 99.8% |
| Vihtavuori N135 | <<locked>> | 82% | 58,030 psi | 89% | 2523 fps | 100% |
| Vihtavuori N140 | <<locked>> | 82% | 58,160 psi | 89% | 2543 fps | 100% |
| Vihtavuori N150 | <<locked>> | 86% | 55,492 psi | 85% | 2546 fps | 100% |
| Vihtavuori N160 | <<locked>> | 90% | 57,580 psi | 89% | 2641 fps | 100% |
| Vihtavuori N165ᴾ | <<locked>> | 100% | 56,652 psi | 87% | 2651 fps | 99.6% |
| Vihtavuori N540 | <<locked>> | 82% | 56,057 psi | 86% | 2539 fps | 100% |
| Vihtavuori N550 | <<locked>> | 90% | 56,840 psi | 87% | 2651 fps | 100% |
| Vihtavuori N555 | <<locked>> | 98% | 58,262 psi | 90% | 2713 fps | 100% |
| Vihtavuori N560 | <<locked>> | 98% | 58,566 psi | 90% | 2789 fps | 98.7% |
| Vihtavuori N565ᴾ | <<locked>> | 100% | 50,067 psi | 77% | 2651 fps | 97.5% |
| Winchester 6.5 StaBALL | <<locked>> | 90% | 57,145 psi | 88% | 2608 fps | 100% |
| Winchester 760 | <<locked>> | 88% | 55,695 psi | 86% | 2671 fps | 99.9% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 51,837 psi | 80% | 2766 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 98% | 57,319 psi | 88% | 2671 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% | 52,924 psi | 81% | 2530 fps | 99.4% |
| Accurate 3100 | <<locked>> | 80% | 30,153 psi | 46% | 2182 fps | 95.8% |
| Accurate 4064 | <<locked>> | 80% | 52,779 psi | 81% | 2507 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 40,785 psi | 63% | 2415 fps | 99.7% |
| Accurate MAGPRO | <<locked>> | 92% | 46,514 psi | 72% | 2605 fps | 95.8% |
| ADI AR 2208 | <<locked>> | 80% | 49,443 psi | 76% | 2493 fps | 100% |
| ADI AR 2209 | <<locked>> | 82% | 36,695 psi | 56% | 2349 fps | 95.1% |
| ADI AR 2213 | <<locked>> | 90% | 42,540 psi | 65% | 2497 fps | 95.6% |
| ADI AR 2217 | <<locked>> | 98% | 40,625 psi | 63% | 2454 fps | 95.1% |
| ADI AR 2225 | <<locked>> | 96% | 33,678 psi | 52% | 2359 fps | 95.9% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 50,256 psi | 77% | 2516 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 53,388 psi | 82% | 2579 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 80% | 39,392 psi | 61% | 2425 fps | 99.8% |
| Alliant Reloder-17 | <<locked>> | 80% | 44,947 psi | 69% | 2533 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 82% | 36,651 psi | 56% | 2349 fps | 95.3% |
| Alliant Reloder-22 | <<locked>> | 86% | 36,941 psi | 57% | 2398 fps | 95.6% |
| Alliant Reloder-23 | <<locked>> | 80% | 29,095 psi | 45% | 2211 fps | 98.8% |
| Alliant Reloder-25 | <<locked>> | 84% | 29,008 psi | 45% | 2224 fps | 95.7% |
| Alliant Reloder-26 | 50 gr | 80% | 31,169 psi | 48% | 2323 fps | 97.6% |
| Baschieri & Pellagri 109 | <<locked>> | 98% | 54,418 psi | 84% | 2631 fps | 95.4% |
| Bofors RP15 | <<locked>> | 88% | 36,477 psi | 56% | 2388 fps | 95.2% |
| Bofors RP3 | <<locked>> | 80% | 50,647 psi | 78% | 2526 fps | 100% |
| Bofors RP30 | <<locked>> | 96% | 38,508 psi | 59% | 2464 fps | 95.2% |
| Bofors RP5 | <<locked>> | 86% | 36,941 psi | 57% | 2398 fps | 95.6% |
| Bofors RP7 | <<locked>> | 80% | 44,454 psi | 68% | 2425 fps | 98.4% |
| Hodgdon H1000 | <<locked>> | 94% | 38,928 psi | 60% | 2425 fps | 95.2% |
| Hodgdon H380 | <<locked>> | 80% | 50,821 psi | 78% | 2543 fps | 100% |
| Hodgdon H414 | <<locked>> | 80% | 42,511 psi | 65% | 2457 fps | 98.5% |
| Hodgdon H4350 | <<locked>> | 80% | 45,339 psi | 70% | 2474 fps | 98% |
| Hodgdon H4831 | <<locked>> | 88% | 42,641 psi | 66% | 2451 fps | 95% |
| Hodgdon H4831 SC | <<locked>> | 90% | 44,585 psi | 69% | 2487 fps | 95.6% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 37,057 psi | 57% | 2323 fps | 99.9% |
| Hodgdon Retumbo | <<locked>> | 92% | 36,448 psi | 56% | 2457 fps | 95.8% |
| Hodgdon Superformance | <<locked>> | 80% | 41,553 psi | 64% | 2480 fps | 98.1% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,586 psi | 42% | 1434 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 52,025 psi | 80% | 2523 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 80% | 54,114 psi | 83% | 2556 fps | 99.8% |
| IMR 4350 | <<locked>> | 80% | 40,001 psi | 62% | 2362 fps | 97.4% |
| IMR 4451 Enduron | <<locked>> | 80% | 45,788 psi | 70% | 2451 fps | 98.9% |
| IMR 4831 | <<locked>> | 80% | 39,044 psi | 60% | 2372 fps | 99.6% |
| IMR 4895 | <<locked>> | 80% | 54,795 psi | 84% | 2602 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 88% | 44,498 psi | 68% | 2451 fps | 95.8% |
| IMR 7828 SSC | <<locked>> | 90% | 40,799 psi | 63% | 2477 fps | 95.2% |
| Lovex S062 | <<locked>> | 80% | 52,373 psi | 81% | 2516 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 43,265 psi | 67% | 2405 fps | 99.4% |
| Lovex S070 | <<locked>> | 80% | 41,510 psi | 64% | 2392 fps | 98.4% |
| Lovex S071 | <<locked>> | 84% | 29,631 psi | 46% | 2172 fps | 95.5% |
| Norma 203B | <<locked>> | 80% | 52,750 psi | 81% | 2566 fps | 100% |
| Norma 204 | <<locked>> | 80% | 39,378 psi | 61% | 2388 fps | 96% |
| Norma MRP | 49.8 gr | 82% | 33,692 psi | 52% | 2352 fps | 95.9% |
| Norma URP | <<locked>> | 80% | 40,335 psi | 62% | 2408 fps | 99.6% |
| Ramshot Big Game | <<locked>> | 80% | 53,505 psi | 82% | 2592 fps | 100% |
| Ramshot Grand | <<locked>> | 90% | 40,422 psi | 62% | 2484 fps | 95.5% |
| Ramshot Hunter | <<locked>> | 80% | 39,059 psi | 60% | 2402 fps | 98.5% |
| Ramshot Magnum | <<locked>> | 90% | 35,737 psi | 55% | 2369 fps | 95.9% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,137 psi | 43% | 1467 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 50,763 psi | 78% | 2533 fps | 99.8% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 47,703 psi | 73% | 2575 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 40,683 psi | 63% | 2438 fps | 99.6% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 39,175 psi | 60% | 2451 fps | 99.4% |
| ReloadSwiss RS 76 | <<locked>> | 90% | 33,272 psi | 51% | 2379 fps | 95.5% |
| Rottweil R 902 | <<locked>> | 80% | 54,186 psi | 83% | 2526 fps | 100% |
| Rottweil R 903 | <<locked>> | 80% | 47,805 psi | 74% | 2480 fps | 100% |
| Rottweil R 904 | <<locked>> | 84% | 40,785 psi | 63% | 2388 fps | 95.3% |
| Rottweil R 905 | <<locked>> | 82% | 35,694 psi | 55% | 2329 fps | 95.2% |
| Rottweil R 907 | <<locked>> | 80% | 44,454 psi | 68% | 2425 fps | 98.4% |
| Shooters World Long Rifle | <<locked>> | 80% | 43,265 psi | 67% | 2405 fps | 99.4% |
| Shooters World Precision | <<locked>> | 80% | 52,373 psi | 81% | 2516 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 41,510 psi | 64% | 2392 fps | 98.4% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 48,863 psi | 75% | 2530 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 48,617 psi | 75% | 2379 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 42,308 psi | 65% | 2356 fps | 98.4% |
| SNPE Vectan Tubal 8000 | <<locked>> | 82% | 35,360 psi | 54% | 2326 fps | 95% |
| Somchem S355 | <<locked>> | 80% | 47,921 psi | 74% | 2477 fps | 100% |
| Somchem S361 | <<locked>> | 86% | 44,251 psi | 68% | 2428 fps | 95.4% |
| Somchem S365 | <<locked>> | 80% | 37,043 psi | 57% | 2372 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 33,997 psi | 52% | 2267 fps | 95.5% |
| Vihtavuori N135 | <<locked>> | 80% | 54,621 psi | 84% | 2484 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 54,520 psi | 84% | 2497 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 45,759 psi | 70% | 2411 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 41,713 psi | 64% | 2405 fps | 99.7% |
| Vihtavuori N165 | <<locked>> | 86% | 35,766 psi | 55% | 2303 fps | 95.7% |
| Vihtavuori N540 | <<locked>> | 80% | 52,605 psi | 81% | 2493 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 41,104 psi | 63% | 2408 fps | 99.6% |
| Vihtavuori N555 | <<locked>> | 80% | 32,460 psi | 50% | 2280 fps | 98.7% |
| Vihtavuori N560 | 53.4 gr | 88% | 41,669 psi | 64% | 2507 fps | 95% |
| Vihtavuori N565 | <<locked>> | 94% | 41,118 psi | 63% | 2490 fps | 95.2% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 40,770 psi | 63% | 2375 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 42,757 psi | 66% | 2464 fps | 98.6% |
| Winchester StaBALL HD | <<locked>> | 80% | 25,672 psi | 39% | 2208 fps | 98.5% |
| Winchester Supreme 780 | <<locked>> | 86% | 38,087 psi | 59% | 2356 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 96 powders for .280 Ackley Improved loaded with the .284 | 180gr | Sierra MatchKing. Norma MRP delivers the highest muzzle velocity at 2,795 fps; across all powders the maximum-charge window runs from 1,604 fps to 2,795 fps. ADI AR 2217 gives the best case fill at 100 %, and 96 of the 96 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (448 MPa), the top charges use 52–90 %, leaving at least 10 % headroom. The 180.0 gr projectile in 0.284" calls for a 1:10.0 twist; slower twists will usually not stabilise this weight. ADI AR 2217, ADI AR 2225, Alliant Reloder-22 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, Norma MRP, Vihtavuori N560 rank at the top here: for .280 Ackley Improved with the .284 | 180gr | Sierra MatchKing 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.