Load Specifications
Load data in caliber .280 Ackley Improved with .284 | 173gr | RWS H-Mantel bullet and 90 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% | 55,724 psi | 86% | 2621 fps | 99.5% |
| Accurate 3100ᴾ | <<locked>> | 100% | 58,320 psi | 90% | 2730 fps | 100% |
| Accurate 4064 | <<locked>> | 82% | 55,738 psi | 86% | 2605 fps | 100% |
| Accurate 4350 | <<locked>> | 90% | 56,681 psi | 87% | 2720 fps | 100% |
| Accurate MAGPRO | <<locked>> | 98% | 56,724 psi | 87% | 2822 fps | 97.6% |
| ADI AR 2208 | <<locked>> | 86% | 58,726 psi | 90% | 2680 fps | 100% |
| ADI AR 2209 | <<locked>> | 96% | 57,217 psi | 88% | 2766 fps | 99.3% |
| ADI AR 2213 | <<locked>> | 98% | 55,042 psi | 85% | 2769 fps | 98.2% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 37,753 psi | 58% | 2503 fps | 97.2% |
| Alliant Power Pro 2000-MR | <<locked>> | 82% | 58,798 psi | 90% | 2805 fps | 100% |
| Alliant Reloder- TS 15.5 | <<locked>> | 84% | 56,318 psi | 87% | 2657 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 82% | 56,347 psi | 87% | 2677 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 92% | 57,174 psi | 88% | 2766 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 88% | 58,639 psi | 90% | 2785 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 96% | 56,550 psi | 87% | 2753 fps | 99.2% |
| Alliant Reloder-22ᴾ | <<locked>> | 100% | 58,102 psi | 89% | 2818 fps | 99.5% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 54,868 psi | 84% | 2736 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 47,587 psi | 73% | 2687 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 96% | 55,100 psi | 85% | 2825 fps | 100% |
| Bofors RP15ᴾ | <<locked>> | 100% | 53,258 psi | 82% | 2746 fps | 98.9% |
| Bofors RP3 | <<locked>> | 84% | 57,072 psi | 88% | 2671 fps | 100% |
| Bofors RP30ᴾ | <<locked>> | 100% | 43,439 psi | 67% | 2615 fps | 96.4% |
| Bofors RP5ᴾ | <<locked>> | 100% | 58,102 psi | 89% | 2818 fps | 99.5% |
| Bofors RP7 | <<locked>> | 88% | 56,289 psi | 87% | 2667 fps | 99.6% |
| Hodgdon H1000ᴾ | <<locked>> | 100% | 47,123 psi | 72% | 2631 fps | 97.4% |
| Hodgdon H380 | <<locked>> | 84% | 57,464 psi | 88% | 2694 fps | 100% |
| Hodgdon H414 | <<locked>> | 90% | 58,682 psi | 90% | 2772 fps | 99.9% |
| Hodgdon H4350 | <<locked>> | 88% | 57,841 psi | 89% | 2726 fps | 99.5% |
| Hodgdon H4831 | <<locked>> | 98% | 58,769 psi | 90% | 2766 fps | 98.2% |
| Hodgdon H4831 SC | <<locked>> | 98% | 57,798 psi | 89% | 2749 fps | 98% |
| Hodgdon Hybrid 100V | <<locked>> | 94% | 57,522 psi | 88% | 2690 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 46,499 psi | 72% | 2730 fps | 98.7% |
| Hodgdon Superformance | <<locked>> | 88% | 55,056 psi | 85% | 2756 fps | 99.7% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,680 psi | 56% | 1644 fps | 100% |
| IMR 4064 | <<locked>> | 84% | 58,073 psi | 89% | 2661 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 82% | 57,101 psi | 88% | 2654 fps | 99.8% |
| IMR 4350 | <<locked>> | 92% | 57,537 psi | 89% | 2703 fps | 99.7% |
| IMR 4451 Enduron | <<locked>> | 88% | 57,986 psi | 89% | 2694 fps | 99.9% |
| IMR 4831 | <<locked>> | 92% | 56,884 psi | 88% | 2707 fps | 100% |
| IMR 4895 | <<locked>> | 82% | 57,798 psi | 89% | 2700 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 96% | 56,391 psi | 87% | 2694 fps | 97.9% |
| IMR 7828 SSCᴾ | <<locked>> | 100% | 56,202 psi | 86% | 2799 fps | 98.5% |
| Lovex S062 | <<locked>> | 84% | 58,363 psi | 90% | 2654 fps | 100% |
| Lovex S065 | <<locked>> | 90% | 58,146 psi | 89% | 2687 fps | 100% |
| Lovex S070 | <<locked>> | 90% | 56,144 psi | 86% | 2684 fps | 99.9% |
| Lovex S071ᴾ | <<locked>> | 100% | 48,617 psi | 75% | 2592 fps | 99.7% |
| Norma 203B | <<locked>> | 82% | 55,666 psi | 86% | 2664 fps | 100% |
| Norma 204 | <<locked>> | 92% | 58,334 psi | 90% | 2756 fps | 99.3% |
| Norma MRP | <<locked>> | 98% | 57,566 psi | 89% | 2838 fps | 99.9% |
| Norma URP | <<locked>> | 90% | 55,129 psi | 85% | 2700 fps | 100% |
| Ramshot Big Game | <<locked>> | 82% | 56,565 psi | 87% | 2690 fps | 100% |
| Ramshot Grandᴾ | <<locked>> | 100% | 56,855 psi | 87% | 2818 fps | 98.9% |
| Ramshot Hunter | <<locked>> | 92% | 57,363 psi | 88% | 2756 fps | 100% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 50,691 psi | 78% | 2697 fps | 99.2% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,463 psi | 58% | 1683 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 84% | 57,159 psi | 88% | 2680 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 86% | 58,276 psi | 90% | 2776 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 90% | 56,333 psi | 87% | 2740 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 92% | 58,581 psi | 90% | 2822 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 46,499 psi | 72% | 2726 fps | 99.4% |
| Rottweil R 902 | <<locked>> | 82% | 57,000 psi | 88% | 2618 fps | 100% |
| Rottweil R 903 | <<locked>> | 86% | 57,261 psi | 88% | 2667 fps | 100% |
| Rottweil R 904 | <<locked>> | 96% | 58,798 psi | 90% | 2736 fps | 98.7% |
| Rottweil R 905 | <<locked>> | 96% | 56,028 psi | 86% | 2743 fps | 99.3% |
| Rottweil R 907 | <<locked>> | 88% | 56,289 psi | 87% | 2667 fps | 99.6% |
| Shooters World Long Rifle | <<locked>> | 90% | 58,146 psi | 89% | 2687 fps | 100% |
| Shooters World Precision | <<locked>> | 84% | 58,363 psi | 90% | 2654 fps | 100% |
| Shooters World SW4350 | <<locked>> | 90% | 56,144 psi | 86% | 2684 fps | 99.9% |
| SNPE Vectan SP 11 | <<locked>> | 84% | 55,114 psi | 85% | 2677 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 86% | 57,827 psi | 89% | 2549 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 90% | 57,769 psi | 89% | 2648 fps | 99.9% |
| SNPE Vectan Tubal 8000 | <<locked>> | 96% | 55,550 psi | 85% | 2740 fps | 99.2% |
| Somchem S355 | <<locked>> | 86% | 57,203 psi | 88% | 2667 fps | 100% |
| Somchem S361 | <<locked>> | 94% | 56,942 psi | 88% | 2680 fps | 97.8% |
| Somchem S365 | <<locked>> | 94% | 58,421 psi | 90% | 2746 fps | 100% |
| Somchem S385 | <<locked>> | 96% | 56,768 psi | 87% | 2720 fps | 99.7% |
| Vihtavuori N135 | <<locked>> | 82% | 57,595 psi | 89% | 2575 fps | 100% |
| Vihtavuori N140 | <<locked>> | 82% | 57,580 psi | 89% | 2592 fps | 100% |
| Vihtavuori N150 | <<locked>> | 88% | 58,407 psi | 90% | 2638 fps | 100% |
| Vihtavuori N160 | <<locked>> | 90% | 57,232 psi | 88% | 2697 fps | 100% |
| Vihtavuori N165ᴾ | <<locked>> | 100% | 55,883 psi | 86% | 2694 fps | 99.4% |
| Vihtavuori N540 | <<locked>> | 82% | 55,724 psi | 86% | 2592 fps | 100% |
| Vihtavuori N550 | <<locked>> | 90% | 56,086 psi | 86% | 2697 fps | 100% |
| Vihtavuori N555 | <<locked>> | 98% | 57,580 psi | 89% | 2762 fps | 100% |
| Vihtavuori N560 | <<locked>> | 98% | 57,653 psi | 89% | 2831 fps | 98.3% |
| Vihtavuori N565ᴾ | <<locked>> | 100% | 49,530 psi | 76% | 2694 fps | 97.1% |
| Winchester 6.5 StaBALL | <<locked>> | 90% | 56,521 psi | 87% | 2657 fps | 100% |
| Winchester 760 | <<locked>> | 90% | 58,682 psi | 90% | 2772 fps | 99.9% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 50,691 psi | 78% | 2808 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 98% | 56,565 psi | 87% | 2713 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% | 52,286 psi | 80% | 2572 fps | 99.1% |
| Accurate 3100 | <<locked>> | 80% | 29,762 psi | 46% | 2218 fps | 95.1% |
| Accurate 4064 | <<locked>> | 80% | 52,286 psi | 80% | 2559 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 40,277 psi | 62% | 2457 fps | 99.5% |
| Accurate MAGPRO | <<locked>> | 92% | 45,876 psi | 71% | 2644 fps | 95.2% |
| ADI AR 2208 | <<locked>> | 80% | 48,805 psi | 75% | 2539 fps | 100% |
| ADI AR 2209 | <<locked>> | 84% | 38,711 psi | 60% | 2441 fps | 95.5% |
| ADI AR 2213 | <<locked>> | 90% | 41,989 psi | 65% | 2536 fps | 95% |
| ADI AR 2225 | <<locked>> | 96% | 33,286 psi | 51% | 2388 fps | 95.1% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 54,679 psi | 84% | 2749 fps | 100% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 49,821 psi | 77% | 2566 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 52,881 psi | 81% | 2628 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 80% | 39,015 psi | 60% | 2467 fps | 99.6% |
| Alliant Reloder-17 | <<locked>> | 80% | 44,309 psi | 68% | 2579 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 84% | 38,609 psi | 59% | 2441 fps | 95.6% |
| Alliant Reloder-22 | <<locked>> | 88% | 38,798 psi | 60% | 2487 fps | 95.8% |
| Alliant Reloder-23 | <<locked>> | 80% | 28,776 psi | 44% | 2247 fps | 98.3% |
| Alliant Reloder-25 | <<locked>> | 86% | 30,501 psi | 47% | 2310 fps | 96% |
| Alliant Reloder-26 | 51.1 gr | 80% | 30,821 psi | 47% | 2359 fps | 97.1% |
| Bofors RP15 | <<locked>> | 90% | 38,493 psi | 59% | 2477 fps | 95.5% |
| Bofors RP3 | <<locked>> | 80% | 50,111 psi | 77% | 2575 fps | 100% |
| Bofors RP30 | <<locked>> | 98% | 40,625 psi | 63% | 2556 fps | 95.5% |
| Bofors RP5 | <<locked>> | 88% | 38,798 psi | 60% | 2487 fps | 95.8% |
| Bofors RP7 | <<locked>> | 80% | 43,830 psi | 67% | 2464 fps | 98% |
| Hodgdon H1000 | <<locked>> | 96% | 41,191 psi | 63% | 2516 fps | 95.6% |
| Hodgdon H380 | <<locked>> | 80% | 50,531 psi | 78% | 2595 fps | 100% |
| Hodgdon H414 | <<locked>> | 80% | 42,235 psi | 65% | 2507 fps | 98.2% |
| Hodgdon H4350 | <<locked>> | 80% | 44,846 psi | 69% | 2516 fps | 97.6% |
| Hodgdon H4831 | <<locked>> | 90% | 44,991 psi | 69% | 2546 fps | 95.3% |
| Hodgdon H4831 SC | <<locked>> | 90% | 44,005 psi | 68% | 2526 fps | 95% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 36,666 psi | 56% | 2365 fps | 99.8% |
| Hodgdon Retumbo | <<locked>> | 92% | 36,143 psi | 56% | 2493 fps | 95.1% |
| Hodgdon Superformance | <<locked>> | 80% | 41,046 psi | 63% | 2520 fps | 97.6% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,456 psi | 42% | 1467 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 51,343 psi | 79% | 2569 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 80% | 53,621 psi | 82% | 2605 fps | 99.6% |
| IMR 4350 | <<locked>> | 80% | 39,566 psi | 61% | 2405 fps | 97% |
| IMR 4451 Enduron | <<locked>> | 80% | 45,411 psi | 70% | 2493 fps | 98.6% |
| IMR 4831 | <<locked>> | 80% | 38,624 psi | 59% | 2411 fps | 99.3% |
| IMR 4895 | <<locked>> | 80% | 54,273 psi | 83% | 2651 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 88% | 44,092 psi | 68% | 2493 fps | 95.2% |
| IMR 7828 SSC | <<locked>> | 92% | 43,018 psi | 66% | 2569 fps | 95.5% |
| Lovex S062 | <<locked>> | 80% | 51,692 psi | 80% | 2562 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 42,873 psi | 66% | 2448 fps | 99.1% |
| Lovex S070 | <<locked>> | 80% | 41,118 psi | 63% | 2434 fps | 98.1% |
| Lovex S071 | <<locked>> | 86% | 31,125 psi | 48% | 2251 fps | 95.7% |
| Norma 203B | <<locked>> | 80% | 52,243 psi | 80% | 2615 fps | 100% |
| Norma 204 | <<locked>> | 80% | 39,102 psi | 60% | 2431 fps | 95.5% |
| Norma MRP | 50.8 gr | 82% | 33,170 psi | 51% | 2385 fps | 95.1% |
| Norma URP | <<locked>> | 80% | 39,885 psi | 61% | 2451 fps | 99.4% |
| Ramshot Big Game | <<locked>> | 80% | 52,779 psi | 81% | 2641 fps | 100% |
| Ramshot Grand | <<locked>> | 92% | 42,830 psi | 66% | 2579 fps | 95.8% |
| Ramshot Hunter | <<locked>> | 80% | 38,769 psi | 60% | 2444 fps | 98.1% |
| Ramshot Magnum | <<locked>> | 90% | 35,331 psi | 54% | 2402 fps | 95.2% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,992 psi | 43% | 1503 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 50,169 psi | 77% | 2575 fps | 99.6% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 47,021 psi | 72% | 2621 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 40,074 psi | 62% | 2477 fps | 99.4% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 38,580 psi | 59% | 2487 fps | 99% |
| ReloadSwiss RS 76 | <<locked>> | 92% | 35,186 psi | 54% | 2470 fps | 96% |
| Rottweil R 902 | <<locked>> | 80% | 53,505 psi | 82% | 2572 fps | 100% |
| Rottweil R 903 | <<locked>> | 80% | 47,297 psi | 73% | 2530 fps | 100% |
| Rottweil R 904 | <<locked>> | 86% | 42,989 psi | 66% | 2480 fps | 95.6% |
| Rottweil R 905 | <<locked>> | 84% | 37,710 psi | 58% | 2421 fps | 95.5% |
| Rottweil R 907 | <<locked>> | 80% | 43,830 psi | 67% | 2464 fps | 98% |
| Shooters World Long Rifle | <<locked>> | 80% | 42,873 psi | 66% | 2448 fps | 99.1% |
| Shooters World Precision | <<locked>> | 80% | 51,692 psi | 80% | 2562 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 41,118 psi | 63% | 2434 fps | 98.1% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 48,530 psi | 75% | 2582 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 48,095 psi | 74% | 2425 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 41,872 psi | 64% | 2395 fps | 98.1% |
| SNPE Vectan Tubal 8000 | <<locked>> | 84% | 37,362 psi | 57% | 2418 fps | 95.3% |
| Somchem S355 | <<locked>> | 80% | 47,485 psi | 73% | 2526 fps | 100% |
| Somchem S361 | <<locked>> | 88% | 46,760 psi | 72% | 2523 fps | 95.7% |
| Somchem S365 | <<locked>> | 80% | 36,564 psi | 56% | 2411 fps | 100% |
| Somchem S385 | <<locked>> | 82% | 35,853 psi | 55% | 2356 fps | 95.7% |
| Vihtavuori N135 | <<locked>> | 80% | 53,940 psi | 83% | 2530 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 54,027 psi | 83% | 2549 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 45,339 psi | 70% | 2457 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 41,249 psi | 63% | 2448 fps | 99.6% |
| Vihtavuori N165 | <<locked>> | 86% | 35,404 psi | 54% | 2339 fps | 95.1% |
| Vihtavuori N540 | <<locked>> | 80% | 52,359 psi | 81% | 2549 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 40,814 psi | 63% | 2454 fps | 99.4% |
| Vihtavuori N555 | <<locked>> | 80% | 32,010 psi | 49% | 2316 fps | 98.3% |
| Vihtavuori N560 | 55.8 gr | 90% | 44,034 psi | 68% | 2602 fps | 95.3% |
| Vihtavuori N565 | <<locked>> | 96% | 43,323 psi | 67% | 2582 fps | 95.5% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 40,147 psi | 62% | 2415 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 42,235 psi | 65% | 2507 fps | 98.2% |
| Winchester StaBALL HD | <<locked>> | 80% | 25,440 psi | 39% | 2238 fps | 97.9% |
| Winchester Supreme 780 | <<locked>> | 86% | 37,652 psi | 58% | 2392 fps | 95.2% |
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 | 173gr | RWS H-Mantel. Norma MRP delivers the highest muzzle velocity at 2,838 fps; across all powders the maximum-charge window runs from 1,644 fps to 2,838 fps. Accurate 3100 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 51–90 %, leaving at least 10 % headroom. The 173.0 gr projectile in 0.284" calls for a 1:11.0 twist; slower twists will usually not stabilise this weight. Accurate 3100, ADI AR 2217, 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 | 173gr | RWS H-Mantel they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, IMR 8133 Enduron, Norma 217, ReloadSwiss RS 80 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.