Load Specifications
Load data in caliber .280 Ackley Improved with .284 | 175gr | Sierra MatchKing bullet and 92 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 2495 | <<locked>> | 82% | 58,421 psi | 90% | 2569 fps | 100% |
| Accurate 2700 | <<locked>> | 82% | 55,448 psi | 85% | 2602 fps | 99.5% |
| Accurate 3100ᴾ | <<locked>> | 100% | 57,682 psi | 89% | 2703 fps | 100% |
| Accurate 4064 | <<locked>> | 84% | 58,697 psi | 90% | 2621 fps | 100% |
| Accurate 4350 | <<locked>> | 90% | 56,202 psi | 86% | 2694 fps | 100% |
| Accurate MAGPRO | <<locked>> | 98% | 56,188 psi | 86% | 2795 fps | 97.6% |
| ADI AR 2208 | <<locked>> | 86% | 58,392 psi | 90% | 2657 fps | 100% |
| ADI AR 2209 | <<locked>> | 96% | 56,855 psi | 87% | 2743 fps | 99.3% |
| ADI AR 2213ᴾ | <<locked>> | 100% | 58,305 psi | 90% | 2795 fps | 98.7% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 37,391 psi | 58% | 2480 fps | 97.1% |
| Alliant Power Pro 2000-MR | <<locked>> | 82% | 58,218 psi | 90% | 2779 fps | 100% |
| Alliant Reloder- TS 15.5 | <<locked>> | 84% | 55,941 psi | 86% | 2635 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 82% | 55,999 psi | 86% | 2651 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 92% | 56,623 psi | 87% | 2740 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 88% | 58,146 psi | 89% | 2759 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 96% | 56,231 psi | 87% | 2730 fps | 99.2% |
| Alliant Reloder-22ᴾ | <<locked>> | 100% | 57,537 psi | 89% | 2792 fps | 99.5% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 54,505 psi | 84% | 2717 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 47,094 psi | 72% | 2661 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 96% | 54,534 psi | 84% | 2799 fps | 100% |
| Bofors RP15ᴾ | <<locked>> | 100% | 52,634 psi | 81% | 2720 fps | 98.8% |
| Bofors RP3 | <<locked>> | 84% | 56,797 psi | 87% | 2648 fps | 100% |
| Bofors RP30ᴾ | <<locked>> | 100% | 42,917 psi | 66% | 2589 fps | 96.3% |
| Bofors RP5ᴾ | <<locked>> | 100% | 57,537 psi | 89% | 2792 fps | 99.5% |
| Bofors RP7 | <<locked>> | 88% | 56,043 psi | 86% | 2644 fps | 99.6% |
| Hodgdon H1000ᴾ | <<locked>> | 100% | 46,673 psi | 72% | 2605 fps | 97.3% |
| Hodgdon H380 | <<locked>> | 84% | 56,898 psi | 88% | 2667 fps | 100% |
| Hodgdon H414 | <<locked>> | 90% | 58,247 psi | 90% | 2746 fps | 99.9% |
| Hodgdon H4350 | <<locked>> | 88% | 57,696 psi | 89% | 2703 fps | 99.5% |
| Hodgdon H4831 | <<locked>> | 98% | 58,537 psi | 90% | 2740 fps | 98.1% |
| Hodgdon H4831 SC | <<locked>> | 98% | 57,188 psi | 88% | 2723 fps | 97.9% |
| Hodgdon Hybrid 100V | <<locked>> | 94% | 57,029 psi | 88% | 2667 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 82% | 58,334 psi | 90% | 2694 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 46,021 psi | 71% | 2700 fps | 98.6% |
| Hodgdon Superformance | <<locked>> | 90% | 58,581 psi | 90% | 2785 fps | 99.9% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,738 psi | 57% | 1627 fps | 100% |
| IMR 4064 | <<locked>> | 84% | 57,725 psi | 89% | 2638 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 82% | 56,768 psi | 87% | 2631 fps | 99.8% |
| IMR 4350 | <<locked>> | 92% | 57,130 psi | 88% | 2677 fps | 99.7% |
| IMR 4451 Enduron | <<locked>> | 88% | 57,522 psi | 88% | 2667 fps | 99.9% |
| IMR 4831 | <<locked>> | 92% | 56,420 psi | 87% | 2684 fps | 100% |
| IMR 4895 | <<locked>> | 82% | 57,450 psi | 88% | 2677 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 96% | 56,115 psi | 86% | 2671 fps | 97.9% |
| IMR 7828 SSCᴾ | <<locked>> | 100% | 55,637 psi | 86% | 2772 fps | 98.4% |
| Lovex S062 | <<locked>> | 84% | 58,015 psi | 89% | 2628 fps | 100% |
| Lovex S065 | <<locked>> | 90% | 57,638 psi | 89% | 2661 fps | 100% |
| Lovex S070 | <<locked>> | 90% | 55,695 psi | 86% | 2657 fps | 99.9% |
| Lovex S071ᴾ | <<locked>> | 100% | 47,964 psi | 74% | 2566 fps | 99.6% |
| Norma 203B | <<locked>> | 82% | 55,332 psi | 85% | 2641 fps | 100% |
| Norma 204 | <<locked>> | 92% | 57,986 psi | 89% | 2733 fps | 99.3% |
| Norma MRP | <<locked>> | 98% | 57,000 psi | 88% | 2812 fps | 99.9% |
| Norma URP | <<locked>> | 92% | 58,349 psi | 90% | 2726 fps | 100% |
| Ramshot Big Game | <<locked>> | 82% | 56,043 psi | 86% | 2664 fps | 100% |
| Ramshot Grandᴾ | <<locked>> | 100% | 56,318 psi | 87% | 2792 fps | 98.8% |
| Ramshot Hunter | <<locked>> | 92% | 56,971 psi | 88% | 2733 fps | 100% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 50,299 psi | 77% | 2671 fps | 99.1% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,536 psi | 58% | 1670 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 84% | 56,971 psi | 88% | 2657 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 86% | 57,711 psi | 89% | 2749 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 90% | 55,956 psi | 86% | 2717 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 92% | 58,247 psi | 90% | 2799 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 46,166 psi | 71% | 2700 fps | 99.3% |
| Rottweil R 902 | <<locked>> | 82% | 56,608 psi | 87% | 2595 fps | 100% |
| Rottweil R 903 | <<locked>> | 86% | 56,927 psi | 88% | 2644 fps | 100% |
| Rottweil R 904 | <<locked>> | 96% | 58,421 psi | 90% | 2710 fps | 98.7% |
| Rottweil R 905 | <<locked>> | 96% | 55,680 psi | 86% | 2720 fps | 99.3% |
| Rottweil R 907 | <<locked>> | 88% | 56,043 psi | 86% | 2644 fps | 99.6% |
| Shooters World Long Rifle | <<locked>> | 90% | 57,638 psi | 89% | 2661 fps | 100% |
| Shooters World Precision | <<locked>> | 84% | 58,015 psi | 89% | 2628 fps | 100% |
| Shooters World SW4350 | <<locked>> | 90% | 55,695 psi | 86% | 2657 fps | 99.9% |
| SNPE Vectan SP 11 | <<locked>> | 86% | 58,552 psi | 90% | 2703 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 86% | 57,464 psi | 88% | 2526 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 90% | 57,377 psi | 88% | 2621 fps | 99.9% |
| SNPE Vectan Tubal 8000 | <<locked>> | 98% | 58,726 psi | 90% | 2762 fps | 99.5% |
| Somchem S355 | <<locked>> | 86% | 56,884 psi | 88% | 2641 fps | 100% |
| Somchem S361 | <<locked>> | 94% | 56,463 psi | 87% | 2654 fps | 97.7% |
| Somchem S365 | <<locked>> | 94% | 57,914 psi | 89% | 2723 fps | 100% |
| Somchem S385 | <<locked>> | 96% | 56,115 psi | 86% | 2694 fps | 99.6% |
| Vihtavuori N135 | <<locked>> | 82% | 57,145 psi | 88% | 2552 fps | 100% |
| Vihtavuori N140 | <<locked>> | 82% | 57,217 psi | 88% | 2569 fps | 100% |
| Vihtavuori N150 | <<locked>> | 88% | 58,175 psi | 89% | 2615 fps | 100% |
| Vihtavuori N160 | <<locked>> | 90% | 56,753 psi | 87% | 2671 fps | 100% |
| Vihtavuori N165ᴾ | <<locked>> | 100% | 55,347 psi | 85% | 2671 fps | 99.4% |
| Vihtavuori N540 | <<locked>> | 84% | 58,740 psi | 90% | 2612 fps | 100% |
| Vihtavuori N550 | <<locked>> | 90% | 55,666 psi | 86% | 2674 fps | 100% |
| Vihtavuori N555 | <<locked>> | 98% | 56,884 psi | 88% | 2736 fps | 100% |
| Vihtavuori N560 | <<locked>> | 98% | 57,116 psi | 88% | 2805 fps | 98.3% |
| Vihtavuori N565ᴾ | <<locked>> | 100% | 49,023 psi | 75% | 2667 fps | 97% |
| Winchester 6.5 StaBALL | <<locked>> | 90% | 56,246 psi | 87% | 2638 fps | 100% |
| Winchester 760 | <<locked>> | 90% | 58,247 psi | 90% | 2746 fps | 99.9% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 50,024 psi | 77% | 2782 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 98% | 56,289 psi | 87% | 2690 fps | 99.1% |
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% | 54,650 psi | 84% | 2523 fps | 100% |
| Accurate 2700 | <<locked>> | 80% | 52,025 psi | 80% | 2552 fps | 99.1% |
| Accurate 3100 | <<locked>> | 80% | 29,443 psi | 45% | 2195 fps | 95.1% |
| Accurate 4064 | <<locked>> | 80% | 51,837 psi | 80% | 2533 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 39,914 psi | 61% | 2434 fps | 99.5% |
| Accurate MAGPRO | <<locked>> | 92% | 45,324 psi | 70% | 2615 fps | 95.1% |
| ADI AR 2208 | <<locked>> | 80% | 48,675 psi | 75% | 2520 fps | 100% |
| ADI AR 2209 | <<locked>> | 84% | 38,479 psi | 59% | 2421 fps | 95.4% |
| ADI AR 2213 | <<locked>> | 90% | 41,887 psi | 64% | 2516 fps | 95% |
| ADI AR 2225 | <<locked>> | 96% | 33,069 psi | 51% | 2369 fps | 95.1% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 54,346 psi | 84% | 2726 fps | 100% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 49,414 psi | 76% | 2539 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 52,475 psi | 81% | 2602 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 80% | 38,638 psi | 59% | 2444 fps | 99.6% |
| Alliant Reloder-17 | <<locked>> | 80% | 43,976 psi | 68% | 2556 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 84% | 38,363 psi | 59% | 2418 fps | 95.5% |
| Alliant Reloder-22 | <<locked>> | 88% | 38,595 psi | 59% | 2467 fps | 95.8% |
| Alliant Reloder-23 | <<locked>> | 80% | 28,471 psi | 44% | 2224 fps | 98.3% |
| Alliant Reloder-25 | <<locked>> | 86% | 30,313 psi | 47% | 2290 fps | 95.9% |
| Alliant Reloder-26 | 50.2 gr | 80% | 30,429 psi | 47% | 2333 fps | 97% |
| Bofors RP15 | <<locked>> | 90% | 38,087 psi | 59% | 2454 fps | 95.4% |
| Bofors RP3 | <<locked>> | 80% | 49,734 psi | 77% | 2549 fps | 100% |
| Bofors RP30 | <<locked>> | 98% | 40,335 psi | 62% | 2536 fps | 95.5% |
| Bofors RP5 | <<locked>> | 88% | 38,595 psi | 59% | 2467 fps | 95.8% |
| Bofors RP7 | <<locked>> | 80% | 43,714 psi | 67% | 2444 fps | 98% |
| Hodgdon H1000 | <<locked>> | 96% | 40,756 psi | 63% | 2490 fps | 95.5% |
| Hodgdon H380 | <<locked>> | 80% | 50,198 psi | 77% | 2569 fps | 100% |
| Hodgdon H414 | <<locked>> | 80% | 41,930 psi | 65% | 2484 fps | 98.1% |
| Hodgdon H4350 | <<locked>> | 80% | 44,541 psi | 69% | 2493 fps | 97.6% |
| Hodgdon H4831 | <<locked>> | 90% | 44,628 psi | 69% | 2523 fps | 95.2% |
| Hodgdon H4831 SC | <<locked>> | 90% | 43,888 psi | 68% | 2507 fps | 95% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 36,289 psi | 56% | 2343 fps | 99.8% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 54,665 psi | 84% | 2648 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 94% | 38,029 psi | 59% | 2526 fps | 96.1% |
| Hodgdon Superformance | <<locked>> | 80% | 40,640 psi | 63% | 2493 fps | 97.6% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,354 psi | 42% | 1450 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 51,227 psi | 79% | 2549 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 80% | 53,287 psi | 82% | 2579 fps | 99.6% |
| IMR 4350 | <<locked>> | 80% | 39,276 psi | 60% | 2382 fps | 96.9% |
| IMR 4451 Enduron | <<locked>> | 80% | 45,049 psi | 69% | 2470 fps | 98.6% |
| IMR 4831 | <<locked>> | 80% | 38,261 psi | 59% | 2388 fps | 99.3% |
| IMR 4895 | <<locked>> | 80% | 53,853 psi | 83% | 2628 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 88% | 43,656 psi | 67% | 2467 fps | 95.1% |
| IMR 7828 SSC | <<locked>> | 92% | 42,685 psi | 66% | 2546 fps | 95.4% |
| Lovex S062 | <<locked>> | 80% | 51,547 psi | 79% | 2543 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 42,554 psi | 65% | 2425 fps | 99.1% |
| Lovex S070 | <<locked>> | 80% | 40,756 psi | 63% | 2408 fps | 98% |
| Lovex S071 | <<locked>> | 86% | 30,835 psi | 47% | 2231 fps | 95.7% |
| Norma 203B | <<locked>> | 80% | 51,837 psi | 80% | 2592 fps | 100% |
| Norma 204 | <<locked>> | 80% | 38,798 psi | 60% | 2408 fps | 95.4% |
| Norma MRP | 50 gr | 82% | 32,938 psi | 51% | 2365 fps | 95.1% |
| Norma URP | <<locked>> | 80% | 39,523 psi | 61% | 2428 fps | 99.4% |
| Ramshot Big Game | <<locked>> | 80% | 52,518 psi | 81% | 2618 fps | 100% |
| Ramshot Grand | <<locked>> | 92% | 42,279 psi | 65% | 2552 fps | 95.7% |
| Ramshot Hunter | <<locked>> | 80% | 38,450 psi | 59% | 2421 fps | 98.1% |
| Ramshot Magnum | <<locked>> | 90% | 35,070 psi | 54% | 2382 fps | 95.1% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,123 psi | 43% | 1490 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 49,893 psi | 77% | 2552 fps | 99.6% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 46,688 psi | 72% | 2598 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 39,798 psi | 61% | 2454 fps | 99.3% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 38,334 psi | 59% | 2464 fps | 99% |
| ReloadSwiss RS 76 | <<locked>> | 92% | 34,824 psi | 54% | 2448 fps | 95.9% |
| Rottweil R 902 | <<locked>> | 80% | 53,345 psi | 82% | 2552 fps | 100% |
| Rottweil R 903 | <<locked>> | 80% | 46,920 psi | 72% | 2503 fps | 100% |
| Rottweil R 904 | <<locked>> | 86% | 42,511 psi | 65% | 2451 fps | 95.5% |
| Rottweil R 905 | <<locked>> | 84% | 37,420 psi | 58% | 2398 fps | 95.4% |
| Rottweil R 907 | <<locked>> | 80% | 43,714 psi | 67% | 2444 fps | 98% |
| Shooters World Long Rifle | <<locked>> | 80% | 42,554 psi | 65% | 2425 fps | 99.1% |
| Shooters World Precision | <<locked>> | 80% | 51,547 psi | 79% | 2543 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 40,756 psi | 63% | 2408 fps | 98% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 48,225 psi | 74% | 2559 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 47,892 psi | 74% | 2405 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 41,553 psi | 64% | 2372 fps | 98% |
| SNPE Vectan Tubal 8000 | <<locked>> | 84% | 37,072 psi | 57% | 2395 fps | 95.3% |
| Somchem S355 | <<locked>> | 80% | 47,094 psi | 72% | 2500 fps | 100% |
| Somchem S361 | <<locked>> | 88% | 46,456 psi | 71% | 2500 fps | 95.7% |
| Somchem S365 | <<locked>> | 80% | 36,216 psi | 56% | 2392 fps | 100% |
| Somchem S385 | <<locked>> | 82% | 35,607 psi | 55% | 2336 fps | 95.7% |
| Vihtavuori N135 | <<locked>> | 80% | 53,737 psi | 83% | 2510 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 53,650 psi | 83% | 2523 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 44,976 psi | 69% | 2434 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 40,915 psi | 63% | 2425 fps | 99.5% |
| Vihtavuori N165 | <<locked>> | 86% | 34,998 psi | 54% | 2316 fps | 95% |
| Vihtavuori N540 | <<locked>> | 80% | 52,040 psi | 80% | 2526 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 40,495 psi | 62% | 2431 fps | 99.4% |
| Vihtavuori N555 | <<locked>> | 80% | 31,676 psi | 49% | 2297 fps | 98.3% |
| Vihtavuori N560 | 54.9 gr | 90% | 43,729 psi | 67% | 2582 fps | 95.3% |
| Vihtavuori N565 | <<locked>> | 96% | 42,815 psi | 66% | 2559 fps | 95.4% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 39,943 psi | 61% | 2395 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 41,930 psi | 65% | 2484 fps | 98.1% |
| Winchester StaBALL HD | <<locked>> | 80% | 25,251 psi | 39% | 2218 fps | 97.8% |
| Winchester Supreme 780 | <<locked>> | 86% | 37,231 psi | 57% | 2369 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 92 powders for .280 Ackley Improved loaded with the .284 | 175gr | Sierra MatchKing. Norma MRP delivers the highest muzzle velocity at 2,812 fps; across all powders the maximum-charge window runs from 1,627 fps to 2,812 fps. Accurate 3100 gives the best case fill at 100 %, and 92 of the 92 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 1:10.0 twist; slower twists will usually not stabilise this weight. Accurate 3100, ADI AR 2213, ADI AR 2225 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 | 175gr | Sierra MatchKing 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.