Load Specifications
Load data in caliber .280 Ackley Improved with .284 | 174gr | Prvi Partizan PSP BT 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, Vihtavuori N560 and Norma MRP.
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% | 55,941 psi | 86% | 2618 fps | 99.5% |
| Accurate 3100ᴾ | <<locked>> | 100% | 58,639 psi | 90% | 2726 fps | 100% |
| Accurate 4064 | <<locked>> | 82% | 55,985 psi | 86% | 2598 fps | 100% |
| Accurate 4350 | <<locked>> | 90% | 56,971 psi | 88% | 2713 fps | 100% |
| Accurate MAGPRO | <<locked>> | 98% | 57,043 psi | 88% | 2818 fps | 97.8% |
| ADI AR 2208 | <<locked>> | 84% | 55,347 psi | 85% | 2628 fps | 100% |
| ADI AR 2209 | <<locked>> | 96% | 57,493 psi | 88% | 2762 fps | 99.3% |
| ADI AR 2213 | <<locked>> | 98% | 55,317 psi | 85% | 2766 fps | 98.3% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 37,956 psi | 58% | 2503 fps | 97.4% |
| Alliant Reloder- TS 15.5 | <<locked>> | 84% | 56,565 psi | 87% | 2654 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 82% | 56,579 psi | 87% | 2671 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 92% | 57,450 psi | 88% | 2762 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 86% | 55,158 psi | 85% | 2733 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 96% | 56,811 psi | 87% | 2749 fps | 99.3% |
| Alliant Reloder-22ᴾ | <<locked>> | 100% | 58,421 psi | 90% | 2815 fps | 99.6% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 55,172 psi | 85% | 2733 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 47,848 psi | 74% | 2684 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 96% | 55,463 psi | 85% | 2822 fps | 100% |
| Baschieri & Pellagri 109ᴾ | <<locked>> | 100% | 57,493 psi | 88% | 2726 fps | 95.8% |
| Bofors RP15ᴾ | <<locked>> | 100% | 53,548 psi | 82% | 2743 fps | 99% |
| Bofors RP3 | <<locked>> | 84% | 57,334 psi | 88% | 2667 fps | 100% |
| Bofors RP30ᴾ | <<locked>> | 100% | 43,700 psi | 67% | 2612 fps | 96.6% |
| Bofors RP5ᴾ | <<locked>> | 100% | 58,421 psi | 90% | 2815 fps | 99.6% |
| Bofors RP7 | <<locked>> | 88% | 56,521 psi | 87% | 2664 fps | 99.7% |
| Hodgdon H1000ᴾ | <<locked>> | 100% | 47,355 psi | 73% | 2628 fps | 97.5% |
| Hodgdon H380 | <<locked>> | 84% | 57,711 psi | 89% | 2690 fps | 100% |
| Hodgdon H414 | <<locked>> | 88% | 54,998 psi | 85% | 2710 fps | 99.8% |
| Hodgdon H4350 | <<locked>> | 88% | 58,088 psi | 89% | 2723 fps | 99.5% |
| Hodgdon H4831 | <<locked>> | 96% | 55,245 psi | 85% | 2707 fps | 97.7% |
| Hodgdon H4831 SC | <<locked>> | 98% | 58,073 psi | 89% | 2746 fps | 98.1% |
| Hodgdon Hybrid 100V | <<locked>> | 94% | 57,812 psi | 89% | 2687 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 46,746 psi | 72% | 2726 fps | 98.8% |
| Hodgdon Superformance | <<locked>> | 88% | 55,361 psi | 85% | 2753 fps | 99.8% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,709 psi | 56% | 1637 fps | 100% |
| IMR 4064 | <<locked>> | 84% | 58,305 psi | 90% | 2657 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 82% | 57,319 psi | 88% | 2651 fps | 99.9% |
| IMR 4350 | <<locked>> | 92% | 57,783 psi | 89% | 2700 fps | 99.8% |
| IMR 4451 Enduron | <<locked>> | 88% | 58,204 psi | 90% | 2687 fps | 99.9% |
| IMR 4831 | <<locked>> | 92% | 57,159 psi | 88% | 2703 fps | 100% |
| IMR 4895 | <<locked>> | 82% | 58,030 psi | 89% | 2697 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 96% | 56,637 psi | 87% | 2694 fps | 98% |
| IMR 7828 SSCᴾ | <<locked>> | 100% | 56,492 psi | 87% | 2795 fps | 98.6% |
| Lovex S062 | <<locked>> | 84% | 58,595 psi | 90% | 2648 fps | 100% |
| Lovex S065 | <<locked>> | 90% | 58,392 psi | 90% | 2684 fps | 100% |
| Lovex S070 | <<locked>> | 90% | 56,376 psi | 87% | 2680 fps | 99.9% |
| Lovex S071ᴾ | <<locked>> | 100% | 48,878 psi | 75% | 2592 fps | 99.7% |
| Norma 203B | <<locked>> | 82% | 55,898 psi | 86% | 2661 fps | 100% |
| Norma 204 | <<locked>> | 92% | 58,610 psi | 90% | 2753 fps | 99.3% |
| Norma MRP | <<locked>> | 98% | 57,899 psi | 89% | 2835 fps | 100% |
| Norma URP | <<locked>> | 90% | 55,390 psi | 85% | 2697 fps | 100% |
| Ramshot Big Game | <<locked>> | 82% | 56,811 psi | 87% | 2687 fps | 100% |
| Ramshot Grandᴾ | <<locked>> | 100% | 57,174 psi | 88% | 2815 fps | 98.9% |
| Ramshot Hunter | <<locked>> | 92% | 57,638 psi | 89% | 2753 fps | 100% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 50,981 psi | 78% | 2694 fps | 99.2% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,478 psi | 58% | 1680 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 84% | 57,392 psi | 88% | 2677 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 86% | 58,595 psi | 90% | 2772 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 90% | 56,623 psi | 87% | 2736 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 90% | 55,100 psi | 85% | 2766 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 46,760 psi | 72% | 2723 fps | 99.5% |
| Rottweil R 902 | <<locked>> | 82% | 57,217 psi | 88% | 2615 fps | 100% |
| Rottweil R 903 | <<locked>> | 86% | 57,522 psi | 88% | 2664 fps | 100% |
| Rottweil R 904 | <<locked>> | 94% | 55,666 psi | 86% | 2684 fps | 98.3% |
| Rottweil R 905 | <<locked>> | 96% | 56,304 psi | 87% | 2740 fps | 99.3% |
| Rottweil R 907 | <<locked>> | 88% | 56,521 psi | 87% | 2664 fps | 99.7% |
| Shooters World Long Rifle | <<locked>> | 90% | 58,392 psi | 90% | 2684 fps | 100% |
| Shooters World Precision | <<locked>> | 84% | 58,595 psi | 90% | 2648 fps | 100% |
| Shooters World SW4350 | <<locked>> | 90% | 56,376 psi | 87% | 2680 fps | 99.9% |
| SNPE Vectan SP 11 | <<locked>> | 84% | 55,361 psi | 85% | 2674 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 86% | 58,044 psi | 89% | 2546 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 90% | 58,030 psi | 89% | 2641 fps | 99.9% |
| SNPE Vectan Tubal 8000 | <<locked>> | 96% | 55,840 psi | 86% | 2736 fps | 99.3% |
| Somchem S355 | <<locked>> | 86% | 57,450 psi | 88% | 2661 fps | 100% |
| Somchem S361 | <<locked>> | 94% | 57,188 psi | 88% | 2677 fps | 97.9% |
| Somchem S365 | <<locked>> | 94% | 58,740 psi | 90% | 2743 fps | 100% |
| Somchem S385 | <<locked>> | 96% | 57,043 psi | 88% | 2717 fps | 99.7% |
| Vihtavuori N135 | <<locked>> | 82% | 57,827 psi | 89% | 2572 fps | 100% |
| Vihtavuori N140 | <<locked>> | 82% | 57,798 psi | 89% | 2589 fps | 100% |
| Vihtavuori N150 | <<locked>> | 88% | 58,653 psi | 90% | 2635 fps | 100% |
| Vihtavuori N160 | <<locked>> | 90% | 57,493 psi | 88% | 2690 fps | 100% |
| Vihtavuori N165ᴾ | <<locked>> | 100% | 56,173 psi | 86% | 2694 fps | 99.5% |
| Vihtavuori N540 | <<locked>> | 82% | 55,941 psi | 86% | 2589 fps | 100% |
| Vihtavuori N550 | <<locked>> | 90% | 56,347 psi | 87% | 2694 fps | 100% |
| Vihtavuori N555 | <<locked>> | 98% | 57,899 psi | 89% | 2759 fps | 100% |
| Vihtavuori N560 | <<locked>> | 98% | 57,957 psi | 89% | 2828 fps | 98.4% |
| Vihtavuori N565ᴾ | <<locked>> | 100% | 49,821 psi | 77% | 2694 fps | 97.2% |
| Winchester 6.5 StaBALL | <<locked>> | 90% | 56,782 psi | 87% | 2654 fps | 100% |
| Winchester 760 | <<locked>> | 88% | 55,303 psi | 85% | 2717 fps | 99.8% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 51,039 psi | 79% | 2805 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 98% | 56,840 psi | 87% | 2710 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% | 52,504 psi | 81% | 2569 fps | 99.2% |
| Accurate 3100 | <<locked>> | 80% | 29,921 psi | 46% | 2215 fps | 95.3% |
| Accurate 4064 | <<locked>> | 80% | 52,518 psi | 81% | 2556 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 40,495 psi | 62% | 2454 fps | 99.6% |
| Accurate MAGPRO | <<locked>> | 92% | 46,137 psi | 71% | 2641 fps | 95.3% |
| ADI AR 2208 | <<locked>> | 80% | 48,994 psi | 75% | 2536 fps | 100% |
| ADI AR 2209 | <<locked>> | 84% | 38,899 psi | 60% | 2438 fps | 95.6% |
| ADI AR 2213 | <<locked>> | 90% | 42,192 psi | 65% | 2533 fps | 95.1% |
| ADI AR 2225 | <<locked>> | 96% | 33,460 psi | 51% | 2388 fps | 95.3% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 50,038 psi | 77% | 2562 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 53,098 psi | 82% | 2625 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 80% | 39,204 psi | 60% | 2464 fps | 99.7% |
| Alliant Reloder-17 | <<locked>> | 80% | 44,541 psi | 69% | 2575 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 84% | 38,798 psi | 60% | 2438 fps | 95.7% |
| Alliant Reloder-22 | <<locked>> | 86% | 36,506 psi | 56% | 2431 fps | 95% |
| Alliant Reloder-23 | <<locked>> | 80% | 28,935 psi | 45% | 2247 fps | 98.5% |
| Alliant Reloder-25 | <<locked>> | 84% | 28,761 psi | 44% | 2254 fps | 95.1% |
| Alliant Reloder-26 | 51.1 gr | 80% | 30,995 psi | 48% | 2356 fps | 97.2% |
| Baschieri & Pellagri 109 | <<locked>> | 98% | 54,215 psi | 83% | 2674 fps | 95% |
| Bofors RP15 | <<locked>> | 90% | 38,696 psi | 60% | 2477 fps | 95.7% |
| Bofors RP3 | <<locked>> | 80% | 50,343 psi | 77% | 2572 fps | 100% |
| Bofors RP30 | <<locked>> | 98% | 40,857 psi | 63% | 2556 fps | 95.7% |
| Bofors RP5 | <<locked>> | 86% | 36,506 psi | 56% | 2431 fps | 95% |
| Bofors RP7 | <<locked>> | 80% | 44,005 psi | 68% | 2461 fps | 98.1% |
| Hodgdon H1000 | <<locked>> | 96% | 41,408 psi | 64% | 2516 fps | 95.8% |
| Hodgdon H380 | <<locked>> | 80% | 50,749 psi | 78% | 2589 fps | 100% |
| Hodgdon H414 | <<locked>> | 80% | 42,438 psi | 65% | 2500 fps | 98.3% |
| Hodgdon H4350 | <<locked>> | 80% | 45,049 psi | 69% | 2513 fps | 97.7% |
| Hodgdon H4831 | <<locked>> | 90% | 45,208 psi | 70% | 2543 fps | 95.4% |
| Hodgdon H4831 SC | <<locked>> | 90% | 44,208 psi | 68% | 2526 fps | 95.1% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 36,854 psi | 57% | 2362 fps | 99.9% |
| Hodgdon Retumbo | <<locked>> | 92% | 36,332 psi | 56% | 2493 fps | 95.3% |
| Hodgdon Superformance | <<locked>> | 80% | 41,263 psi | 63% | 2516 fps | 97.8% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,470 psi | 42% | 1463 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 51,547 psi | 79% | 2566 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 80% | 53,824 psi | 83% | 2602 fps | 99.7% |
| IMR 4350 | <<locked>> | 80% | 39,740 psi | 61% | 2398 fps | 97.1% |
| IMR 4451 Enduron | <<locked>> | 80% | 45,585 psi | 70% | 2490 fps | 98.7% |
| IMR 4831 | <<locked>> | 80% | 38,812 psi | 60% | 2411 fps | 99.4% |
| IMR 4895 | <<locked>> | 80% | 54,491 psi | 84% | 2648 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 88% | 44,280 psi | 68% | 2490 fps | 95.4% |
| IMR 7828 SSC | <<locked>> | 92% | 43,236 psi | 67% | 2569 fps | 95.6% |
| Lovex S062 | <<locked>> | 80% | 51,895 psi | 80% | 2559 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 43,062 psi | 66% | 2444 fps | 99.2% |
| Lovex S070 | <<locked>> | 80% | 41,307 psi | 64% | 2431 fps | 98.1% |
| Lovex S071 | <<locked>> | 84% | 29,428 psi | 45% | 2201 fps | 95% |
| Norma 203B | <<locked>> | 80% | 52,460 psi | 81% | 2612 fps | 100% |
| Norma 204 | <<locked>> | 80% | 39,291 psi | 60% | 2428 fps | 95.6% |
| Norma MRP | 50.8 gr | 82% | 33,344 psi | 51% | 2382 fps | 95.3% |
| Norma URP | <<locked>> | 80% | 40,089 psi | 62% | 2448 fps | 99.5% |
| Ramshot Big Game | <<locked>> | 80% | 53,011 psi | 82% | 2635 fps | 100% |
| Ramshot Grand | <<locked>> | 92% | 43,062 psi | 66% | 2579 fps | 96% |
| Ramshot Hunter | <<locked>> | 80% | 38,957 psi | 60% | 2441 fps | 98.2% |
| Ramshot Magnum | <<locked>> | 90% | 35,534 psi | 55% | 2402 fps | 95.4% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,007 psi | 43% | 1496 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 50,372 psi | 77% | 2572 fps | 99.7% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 47,268 psi | 73% | 2618 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 40,292 psi | 62% | 2474 fps | 99.4% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 38,769 psi | 60% | 2484 fps | 99.1% |
| ReloadSwiss RS 76 | <<locked>> | 92% | 35,389 psi | 54% | 2474 fps | 96.2% |
| Rottweil R 902 | <<locked>> | 80% | 53,708 psi | 83% | 2569 fps | 100% |
| Rottweil R 903 | <<locked>> | 80% | 47,514 psi | 73% | 2523 fps | 100% |
| Rottweil R 904 | <<locked>> | 86% | 43,178 psi | 66% | 2477 fps | 95.7% |
| Rottweil R 905 | <<locked>> | 84% | 37,913 psi | 58% | 2418 fps | 95.6% |
| Rottweil R 907 | <<locked>> | 80% | 44,005 psi | 68% | 2461 fps | 98.1% |
| Shooters World Long Rifle | <<locked>> | 80% | 43,062 psi | 66% | 2444 fps | 99.2% |
| Shooters World Precision | <<locked>> | 80% | 51,895 psi | 80% | 2559 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 41,307 psi | 64% | 2431 fps | 98.1% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 48,747 psi | 75% | 2579 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 48,269 psi | 74% | 2421 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 42,061 psi | 65% | 2392 fps | 98.2% |
| SNPE Vectan Tubal 8000 | <<locked>> | 84% | 37,565 psi | 58% | 2415 fps | 95.5% |
| Somchem S355 | <<locked>> | 80% | 47,688 psi | 73% | 2523 fps | 100% |
| Somchem S361 | <<locked>> | 86% | 43,903 psi | 68% | 2464 fps | 95% |
| Somchem S365 | <<locked>> | 80% | 36,767 psi | 57% | 2411 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 33,765 psi | 52% | 2300 fps | 95% |
| Vihtavuori N135 | <<locked>> | 80% | 54,172 psi | 83% | 2526 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 54,230 psi | 83% | 2543 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 45,542 psi | 70% | 2454 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 41,452 psi | 64% | 2444 fps | 99.6% |
| Vihtavuori N165 | <<locked>> | 86% | 35,592 psi | 55% | 2339 fps | 95.3% |
| Vihtavuori N540 | <<locked>> | 80% | 52,576 psi | 81% | 2543 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 41,002 psi | 63% | 2451 fps | 99.5% |
| Vihtavuori N555 | <<locked>> | 80% | 32,198 psi | 50% | 2316 fps | 98.4% |
| Vihtavuori N560 | 55.8 gr | 90% | 44,266 psi | 68% | 2602 fps | 95.5% |
| Vihtavuori N565 | <<locked>> | 96% | 43,584 psi | 67% | 2582 fps | 95.6% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 40,335 psi | 62% | 2411 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 42,438 psi | 65% | 2500 fps | 98.3% |
| Winchester StaBALL HD | <<locked>> | 80% | 25,585 psi | 39% | 2238 fps | 98.1% |
| Winchester Supreme 780 | <<locked>> | 86% | 37,840 psi | 58% | 2392 fps | 95.3% |
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 90 powders for .280 Ackley Improved loaded with the .284 | 174gr | Prvi Partizan PSP BT. Norma MRP delivers the highest muzzle velocity at 2,835 fps; across all powders the maximum-charge window runs from 1,637 fps to 2,835 fps. Accurate 3100 gives the best case fill at 100 %, and 90 of the 90 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (448 MPa), the top charges use 56–90 %, leaving at least 10 % headroom. The 174.0 gr projectile in 0.284" calls for a 1:11.0 twist; slower twists will usually not stabilise this weight. Accurate 3100, ADI AR 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, Vihtavuori N560, Norma MRP rank at the top here: for .280 Ackley Improved with the .284 | 174gr | Prvi Partizan PSP BT 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.