Load Specifications
Load data in caliber .280 Ackley Improved with .284 | 175gr | Barnes X S bullet and 87 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Norma MRP, Vihtavuori N560 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.
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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 2700 | <<locked>> | 82% | 57,711 psi | 89% | 2608 fps | 99.6% |
| Accurate 3100 | <<locked>> | 98% | 57,246 psi | 88% | 2674 fps | 100% |
| Accurate 4350 | <<locked>> | 88% | 55,695 psi | 86% | 2661 fps | 100% |
| Accurate MAGPRO | <<locked>> | 98% | 58,697 psi | 90% | 2812 fps | 97.9% |
| ADI AR 2208 | <<locked>> | 84% | 56,913 psi | 88% | 2618 fps | 100% |
| ADI AR 2209 | <<locked>> | 94% | 55,506 psi | 85% | 2700 fps | 99% |
| ADI AR 2213 | <<locked>> | 98% | 56,739 psi | 87% | 2753 fps | 98.3% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 40,030 psi | 62% | 2516 fps | 97.9% |
| Alliant Power Pro Varmint | <<locked>> | 94% | 55,492 psi | 85% | 2697 fps | 99% |
| Alliant Power Pro Varmint | <<locked>> | 94% | 55,492 psi | 85% | 2697 fps | 99% |
| Alliant Reloder- TS 15.5 | <<locked>> | 84% | 58,291 psi | 90% | 2641 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 82% | 58,537 psi | 90% | 2664 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 90% | 55,448 psi | 85% | 2703 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 86% | 56,782 psi | 87% | 2723 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 96% | 58,363 psi | 90% | 2740 fps | 99.4% |
| Alliant Reloder-22 | <<locked>> | 98% | 56,333 psi | 87% | 2753 fps | 99.3% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 56,840 psi | 87% | 2723 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 49,661 psi | 76% | 2680 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 96% | 57,232 psi | 88% | 2818 fps | 100% |
| Baschieri & Pellagri 109ᴾ | <<locked>> | 100% | 58,668 psi | 90% | 2710 fps | 95.7% |
| Bofors RP15ᴾ | <<locked>> | 100% | 55,201 psi | 85% | 2736 fps | 99.1% |
| Bofors RP3 | <<locked>> | 82% | 56,347 psi | 87% | 2618 fps | 100% |
| Bofors RP30ᴾ | <<locked>> | 100% | 45,788 psi | 70% | 2618 fps | 97% |
| Bofors RP5 | <<locked>> | 98% | 56,333 psi | 87% | 2753 fps | 99.3% |
| Bofors RP7 | <<locked>> | 88% | 58,436 psi | 90% | 2654 fps | 99.7% |
| Hodgdon H1000ᴾ | <<locked>> | 100% | 48,892 psi | 75% | 2621 fps | 97.6% |
| Hodgdon H380 | <<locked>> | 82% | 56,130 psi | 86% | 2631 fps | 100% |
| Hodgdon H414 | <<locked>> | 88% | 56,739 psi | 87% | 2703 fps | 99.9% |
| Hodgdon H4350 | <<locked>> | 86% | 56,246 psi | 87% | 2661 fps | 99.3% |
| Hodgdon H4831 | <<locked>> | 96% | 56,855 psi | 87% | 2697 fps | 97.8% |
| Hodgdon H4831 SC | <<locked>> | 96% | 55,608 psi | 86% | 2677 fps | 97.5% |
| Hodgdon Hybrid 100V | <<locked>> | 92% | 56,159 psi | 86% | 2635 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 48,646 psi | 75% | 2726 fps | 99% |
| Hodgdon Superformance | <<locked>> | 88% | 56,753 psi | 87% | 2740 fps | 99.8% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,014 psi | 57% | 1621 fps | 100% |
| IMR 4064 | <<locked>> | 82% | 56,623 psi | 87% | 2602 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 82% | 58,595 psi | 90% | 2635 fps | 99.9% |
| IMR 4350 | <<locked>> | 90% | 55,782 psi | 86% | 2638 fps | 99.6% |
| IMR 4451 Enduron | <<locked>> | 86% | 56,144 psi | 86% | 2628 fps | 99.7% |
| IMR 4831 | <<locked>> | 90% | 55,637 psi | 86% | 2648 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 96% | 58,073 psi | 89% | 2680 fps | 98.1% |
| IMR 7828 SSCᴾ | <<locked>> | 100% | 57,711 psi | 89% | 2782 fps | 98.6% |
| Lovex S062 | <<locked>> | 82% | 57,392 psi | 88% | 2598 fps | 100% |
| Lovex S065 | <<locked>> | 88% | 56,898 psi | 88% | 2628 fps | 100% |
| Lovex S070 | <<locked>> | 90% | 58,378 psi | 90% | 2671 fps | 99.9% |
| Lovex S071ᴾ | <<locked>> | 100% | 51,619 psi | 79% | 2595 fps | 99.8% |
| Norma 203B | <<locked>> | 82% | 57,928 psi | 89% | 2651 fps | 100% |
| Norma 204 | <<locked>> | 90% | 56,362 psi | 87% | 2687 fps | 99% |
| Norma MRP | <<locked>> | 96% | 55,898 psi | 86% | 2776 fps | 99.9% |
| Norma URP | <<locked>> | 90% | 57,174 psi | 88% | 2687 fps | 100% |
| Ramshot Big Game | <<locked>> | 82% | 58,305 psi | 90% | 2674 fps | 100% |
| Ramshot Grandᴾ | <<locked>> | 100% | 58,653 psi | 90% | 2802 fps | 99% |
| Ramshot Hunter | <<locked>> | 90% | 55,695 psi | 86% | 2694 fps | 100% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 52,910 psi | 81% | 2690 fps | 99.3% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,913 psi | 58% | 1660 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 82% | 55,709 psi | 86% | 2618 fps | 99.9% |
| ReloadSwiss RS 60 | <<locked>> | 84% | 56,246 psi | 87% | 2713 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 90% | 58,653 psi | 90% | 2730 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 90% | 56,405 psi | 87% | 2753 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 48,849 psi | 75% | 2726 fps | 99.6% |
| Rottweil R 903 | <<locked>> | 84% | 56,463 psi | 87% | 2615 fps | 100% |
| Rottweil R 904 | <<locked>> | 94% | 57,043 psi | 88% | 2671 fps | 98.4% |
| Rottweil R 905 | <<locked>> | 96% | 58,073 psi | 89% | 2730 fps | 99.4% |
| Rottweil R 907 | <<locked>> | 88% | 58,436 psi | 90% | 2654 fps | 99.7% |
| Shooters World Long Rifle | <<locked>> | 88% | 56,898 psi | 88% | 2628 fps | 100% |
| Shooters World Precision | <<locked>> | 82% | 57,392 psi | 88% | 2598 fps | 100% |
| Shooters World SW4350 | <<locked>> | 90% | 58,378 psi | 90% | 2671 fps | 99.9% |
| SNPE Vectan SP 11 | <<locked>> | 84% | 57,203 psi | 88% | 2664 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 84% | 56,246 psi | 87% | 2490 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 88% | 56,289 psi | 87% | 2585 fps | 99.8% |
| SNPE Vectan Tubal 8000 | <<locked>> | 96% | 57,580 psi | 89% | 2726 fps | 99.4% |
| Somchem S355 | <<locked>> | 84% | 56,173 psi | 86% | 2608 fps | 100% |
| Somchem S361 | <<locked>> | 92% | 55,100 psi | 85% | 2612 fps | 97.4% |
| Somchem S365 | <<locked>> | 92% | 56,956 psi | 88% | 2690 fps | 100% |
| Somchem S385 | <<locked>> | 94% | 55,274 psi | 85% | 2657 fps | 99.5% |
| Vihtavuori N150 | <<locked>> | 86% | 56,956 psi | 88% | 2579 fps | 100% |
| Vihtavuori N160 | <<locked>> | 88% | 55,622 psi | 86% | 2631 fps | 100% |
| Vihtavuori N165ᴾ | <<locked>> | 100% | 57,899 psi | 89% | 2684 fps | 99.5% |
| Vihtavuori N540 | <<locked>> | 82% | 57,667 psi | 89% | 2575 fps | 100% |
| Vihtavuori N550 | <<locked>> | 90% | 58,436 psi | 90% | 2687 fps | 100% |
| Vihtavuori N555 | <<locked>> | 96% | 56,536 psi | 87% | 2710 fps | 100% |
| Vihtavuori N560 | <<locked>> | 96% | 55,927 psi | 86% | 2766 fps | 98% |
| Vihtavuori N565ᴾ | <<locked>> | 100% | 51,880 psi | 80% | 2690 fps | 97.5% |
| Winchester 6.5 StaBALL | <<locked>> | 90% | 58,378 psi | 90% | 2644 fps | 100% |
| Winchester 760 | <<locked>> | 88% | 57,029 psi | 88% | 2707 fps | 99.9% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 52,953 psi | 81% | 2808 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 98% | 58,436 psi | 90% | 2700 fps | 99.3% |
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% | 54,186 psi | 83% | 2559 fps | 99.3% |
| Accurate 3100 | <<locked>> | 80% | 32,895 psi | 51% | 2247 fps | 96.4% |
| Accurate 4350 | <<locked>> | 80% | 43,265 psi | 67% | 2467 fps | 99.8% |
| Accurate MAGPRO | <<locked>> | 92% | 48,037 psi | 74% | 2641 fps | 95.7% |
| ADI AR 2208 | <<locked>> | 80% | 50,734 psi | 78% | 2530 fps | 100% |
| ADI AR 2209 | <<locked>> | 82% | 38,363 psi | 59% | 2392 fps | 95.2% |
| ADI AR 2213 | <<locked>> | 90% | 44,005 psi | 68% | 2536 fps | 95.5% |
| ADI AR 2225 | <<locked>> | 94% | 33,634 psi | 52% | 2356 fps | 95.1% |
| Alliant Power Pro Varmint | <<locked>> | 82% | 38,725 psi | 60% | 2398 fps | 95.4% |
| Alliant Power Pro Varmint | <<locked>> | 82% | 38,725 psi | 60% | 2398 fps | 95.4% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 51,938 psi | 80% | 2556 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 55,013 psi | 85% | 2615 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 80% | 40,944 psi | 63% | 2464 fps | 99.8% |
| Alliant Reloder-17 | <<locked>> | 80% | 46,601 psi | 72% | 2575 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 82% | 38,363 psi | 59% | 2392 fps | 95.4% |
| Alliant Reloder-22 | <<locked>> | 86% | 38,682 psi | 60% | 2444 fps | 95.7% |
| Alliant Reloder-23 | <<locked>> | 80% | 31,198 psi | 48% | 2270 fps | 99.1% |
| Alliant Reloder-25 | <<locked>> | 82% | 29,269 psi | 45% | 2231 fps | 95.2% |
| Alliant Reloder-26 | 49.4 gr | 80% | 33,475 psi | 51% | 2388 fps | 98.1% |
| Baschieri & Pellagri 109 | <<locked>> | 98% | 55,361 psi | 85% | 2657 fps | 95% |
| Bofors RP15 | <<locked>> | 88% | 38,450 psi | 59% | 2438 fps | 95.4% |
| Bofors RP3 | <<locked>> | 80% | 52,866 psi | 81% | 2569 fps | 100% |
| Bofors RP30 | <<locked>> | 96% | 40,553 psi | 62% | 2516 fps | 95.4% |
| Bofors RP5 | <<locked>> | 86% | 38,682 psi | 60% | 2444 fps | 95.7% |
| Bofors RP7 | <<locked>> | 80% | 46,238 psi | 71% | 2464 fps | 98.3% |
| Hodgdon H1000 | <<locked>> | 94% | 40,712 psi | 63% | 2464 fps | 95.2% |
| Hodgdon H380 | <<locked>> | 80% | 52,678 psi | 81% | 2582 fps | 100% |
| Hodgdon H414 | <<locked>> | 80% | 44,280 psi | 68% | 2500 fps | 98.5% |
| Hodgdon H4350 | <<locked>> | 80% | 46,818 psi | 72% | 2510 fps | 97.9% |
| Hodgdon H4831 | <<locked>> | 90% | 46,760 psi | 72% | 2536 fps | 95.6% |
| Hodgdon H4831 SC | <<locked>> | 90% | 46,064 psi | 71% | 2523 fps | 95.5% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 38,856 psi | 60% | 2365 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 92% | 38,305 psi | 59% | 2507 fps | 96% |
| Hodgdon Superformance | <<locked>> | 80% | 43,091 psi | 66% | 2520 fps | 98% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,978 psi | 43% | 1450 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 53,417 psi | 82% | 2556 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 80% | 55,361 psi | 85% | 2589 fps | 99.7% |
| IMR 4350 | <<locked>> | 80% | 41,553 psi | 64% | 2402 fps | 97.4% |
| IMR 4451 Enduron | <<locked>> | 80% | 47,166 psi | 73% | 2484 fps | 98.8% |
| IMR 4831 | <<locked>> | 80% | 41,147 psi | 63% | 2418 fps | 99.6% |
| IMR 4955 Enduron | <<locked>> | 88% | 45,803 psi | 70% | 2484 fps | 95.6% |
| IMR 7828 SSC | <<locked>> | 90% | 42,409 psi | 65% | 2516 fps | 95.1% |
| Lovex S062 | <<locked>> | 80% | 54,172 psi | 83% | 2556 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 45,179 psi | 70% | 2444 fps | 99.4% |
| Lovex S070 | <<locked>> | 80% | 43,526 psi | 67% | 2434 fps | 98.5% |
| Lovex S071 | <<locked>> | 82% | 30,501 psi | 47% | 2192 fps | 95.5% |
| Norma 203B | <<locked>> | 80% | 54,433 psi | 84% | 2602 fps | 100% |
| Norma 204 | <<locked>> | 80% | 41,046 psi | 63% | 2428 fps | 96% |
| Norma MRP | 47.9 gr | 80% | 33,446 psi | 51% | 2349 fps | 95.2% |
| Norma URP | <<locked>> | 80% | 42,177 psi | 65% | 2451 fps | 99.7% |
| Ramshot Big Game | <<locked>> | 80% | 54,766 psi | 84% | 2628 fps | 100% |
| Ramshot Grand | <<locked>> | 90% | 41,974 psi | 65% | 2520 fps | 95.4% |
| Ramshot Hunter | <<locked>> | 80% | 40,828 psi | 63% | 2444 fps | 98.5% |
| Ramshot Magnum | <<locked>> | 88% | 35,389 psi | 54% | 2362 fps | 95.1% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,616 psi | 44% | 1483 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 52,373 psi | 81% | 2569 fps | 99.7% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 49,240 psi | 76% | 2615 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 42,554 psi | 65% | 2484 fps | 99.6% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 40,698 psi | 63% | 2490 fps | 99.3% |
| ReloadSwiss RS 76 | <<locked>> | 90% | 35,375 psi | 54% | 2434 fps | 95.9% |
| Rottweil R 903 | <<locked>> | 80% | 49,966 psi | 77% | 2523 fps | 100% |
| Rottweil R 904 | <<locked>> | 84% | 42,206 psi | 65% | 2421 fps | 95.2% |
| Rottweil R 905 | <<locked>> | 82% | 37,637 psi | 58% | 2379 fps | 95.4% |
| Rottweil R 907 | <<locked>> | 80% | 46,238 psi | 71% | 2464 fps | 98.3% |
| Shooters World Long Rifle | <<locked>> | 80% | 45,179 psi | 70% | 2444 fps | 99.4% |
| Shooters World Precision | <<locked>> | 80% | 54,172 psi | 83% | 2556 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 43,526 psi | 67% | 2434 fps | 98.5% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 50,473 psi | 78% | 2569 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 50,024 psi | 77% | 2411 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 44,251 psi | 68% | 2395 fps | 98.5% |
| SNPE Vectan Tubal 8000 | <<locked>> | 82% | 37,289 psi | 57% | 2372 fps | 95.2% |
| Somchem S355 | <<locked>> | 80% | 49,835 psi | 77% | 2516 fps | 100% |
| Somchem S361 | <<locked>> | 86% | 45,905 psi | 71% | 2467 fps | 95.3% |
| Somchem S365 | <<locked>> | 80% | 39,059 psi | 60% | 2421 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 36,216 psi | 56% | 2320 fps | 95.8% |
| Vihtavuori N150 | <<locked>> | 80% | 47,572 psi | 73% | 2451 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 43,497 psi | 67% | 2444 fps | 99.7% |
| Vihtavuori N165 | <<locked>> | 84% | 35,418 psi | 54% | 2300 fps | 95.1% |
| Vihtavuori N540 | <<locked>> | 80% | 54,302 psi | 84% | 2533 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 43,062 psi | 66% | 2454 fps | 99.6% |
| Vihtavuori N555 | <<locked>> | 80% | 34,896 psi | 54% | 2343 fps | 99% |
| Vihtavuori N560 | 52.7 gr | 88% | 43,337 psi | 67% | 2549 fps | 95% |
| Vihtavuori N565 | <<locked>> | 94% | 43,004 psi | 66% | 2539 fps | 95.3% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 42,192 psi | 65% | 2411 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 44,512 psi | 68% | 2507 fps | 98.6% |
| Winchester StaBALL HD | <<locked>> | 80% | 27,992 psi | 43% | 2280 fps | 99.1% |
| Winchester Supreme 780 | <<locked>> | 84% | 37,304 psi | 57% | 2346 fps | 95% |
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 87 powders for .280 Ackley Improved loaded with the .284 | 175gr | Barnes X S. Alliant Reloder-26 delivers the highest muzzle velocity at 2,818 fps; across all powders the maximum-charge window runs from 1,621 fps to 2,818 fps. ADI AR 2225 gives the best case fill at 100 %, and 87 of the 87 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 1:9.5 twist; slower twists will usually not stabilise this weight. ADI AR 2225, Alliant Reloder-23, 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. Norma MRP, Vihtavuori N560, Alliant Reloder-26 rank at the top here: for .280 Ackley Improved with the .284 | 175gr | Barnes X S 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.