Load Specifications
Bullet:.284 | 170gr | Hammer HHT
Bullet Manufacturer:Hammer
Bullet Weight:170 gr
Bullet Diameter:0.284"
Bullet Length:<<locked>>
Caliber:.280 Ackley Improved load data
Case Length (l3):2.54"
Cartridge Length (C.O.L.):<<locked>>
Case Capacity:74 Grains of Water
Primer Size:Large Rifle (LR)
Barrel Length:24"
Max. allowed Pressure:65,000 psi
Recommended Twist Rate:1:8.0
Load data in caliber .280 Ackley Improved with .284 | 170gr | Hammer HHT bullet and 108 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Alliant Reloder-17, ReloadSwiss RS 60 and Hodgdon H414.
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>> | 84% | 57,406 psi | 88% | 2582 fps | 100% |
| Accurate 2700 | <<locked>> | 84% | 55,317 psi | 85% | 2612 fps | 99% |
| Accurate 3100ᴾ | <<locked>> | 100% | 52,431 psi | 81% | 2651 fps | 99.7% |
| Accurate 4064 | <<locked>> | 86% | 57,783 psi | 89% | 2635 fps | 100% |
| Accurate 4350 | <<locked>> | 94% | 58,755 psi | 90% | 2749 fps | 100% |
| Accurate High Countryᴾ | <<locked>> | 100% | 57,276 psi | 88% | 2844 fps | 98.3% |
| Accurate MAGPROᴾ | <<locked>> | 100% | 54,404 psi | 84% | 2785 fps | 96.5% |
| ADI AR 2206H | <<locked>> | 82% | 56,666 psi | 87% | 2664 fps | 100% |
| ADI AR 2208 | <<locked>> | 88% | 57,827 psi | 89% | 2667 fps | 100% |
| ADI AR 2209 | <<locked>> | 98% | 55,767 psi | 86% | 2740 fps | 98.6% |
| ADI AR 2213ᴾ | <<locked>> | 100% | 53,403 psi | 82% | 2733 fps | 97.1% |
| Alliant Power Pro 2000-MR | <<locked>> | 84% | 57,493 psi | 88% | 2795 fps | 100% |
| Alliant Power Pro Varmint | <<locked>> | 98% | 55,796 psi | 86% | 2736 fps | 98.7% |
| Alliant Reloder- TS 15.5 | <<locked>> | 86% | 55,259 psi | 85% | 2648 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 84% | 55,332 psi | 85% | 2664 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 94% | 55,477 psi | 85% | 2746 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 90% | 56,898 psi | 88% | 2772 fps | 100% |
| Alliant Reloder-19ᴾ | <<locked>> | 100% | 58,624 psi | 90% | 2779 fps | 99% |
| Alliant Reloder-22ᴾ | <<locked>> | 100% | 52,083 psi | 80% | 2730 fps | 98.3% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 49,211 psi | 76% | 2667 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 42,931 psi | 66% | 2602 fps | 99.3% |
| Alliant Reloder-26ᴾ | <<locked>> | 100% | 56,333 psi | 87% | 2851 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 82% | 56,782 psi | 87% | 2687 fps | 100% |
| Bofors RP15ᴾ | <<locked>> | 100% | 47,805 psi | 74% | 2661 fps | 97.4% |
| Bofors RP3 | <<locked>> | 86% | 56,144 psi | 86% | 2661 fps | 100% |
| Bofors RP5ᴾ | <<locked>> | 100% | 52,083 psi | 80% | 2730 fps | 98.3% |
| Bofors RP7 | <<locked>> | 90% | 55,274 psi | 85% | 2648 fps | 99.2% |
| Hodgdon H380 | <<locked>> | 86% | 56,492 psi | 87% | 2680 fps | 100% |
| Hodgdon H414 | <<locked>> | 92% | 57,029 psi | 88% | 2746 fps | 99.7% |
| Hodgdon H4350 | <<locked>> | 90% | 56,869 psi | 87% | 2707 fps | 99% |
| Hodgdon H4831ᴾ | <<locked>> | 100% | 57,116 psi | 88% | 2733 fps | 97.2% |
| Hodgdon H4831 SCᴾ | <<locked>> | 100% | 56,086 psi | 86% | 2717 fps | 97% |
| Hodgdon H4895 | <<locked>> | 82% | 57,319 psi | 88% | 2671 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 96% | 55,666 psi | 86% | 2671 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 84% | 57,696 psi | 89% | 2710 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 42,003 psi | 65% | 2625 fps | 96.6% |
| Hodgdon Superformance | <<locked>> | 92% | 57,377 psi | 88% | 2789 fps | 99.6% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,419 psi | 56% | 1624 fps | 100% |
| Hodgdon VARGET | <<locked>> | 84% | 58,494 psi | 90% | 2671 fps | 100% |
| IMR 3031 | <<locked>> | 82% | 58,160 psi | 89% | 2644 fps | 100% |
| IMR 4064 | <<locked>> | 86% | 57,551 psi | 89% | 2654 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 84% | 56,608 psi | 87% | 2641 fps | 99.6% |
| IMR 4350 | <<locked>> | 94% | 56,275 psi | 87% | 2680 fps | 99.3% |
| IMR 4451 Enduron | <<locked>> | 90% | 57,159 psi | 88% | 2677 fps | 99.6% |
| IMR 4831 | <<locked>> | 96% | 58,726 psi | 90% | 2733 fps | 100% |
| IMR 4895 | <<locked>> | 84% | 56,753 psi | 87% | 2690 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 98% | 55,288 psi | 85% | 2671 fps | 97.1% |
| IMR 7828 SSCᴾ | <<locked>> | 100% | 50,720 psi | 78% | 2703 fps | 96.7% |
| Lovex D073.6 | <<locked>> | 82% | 57,232 psi | 88% | 2638 fps | 100% |
| Lovex S060 | <<locked>> | 82% | 55,564 psi | 85% | 2592 fps | 100% |
| Lovex S062 | <<locked>> | 86% | 57,740 psi | 89% | 2648 fps | 100% |
| Lovex S065 | <<locked>> | 92% | 57,174 psi | 88% | 2671 fps | 100% |
| Lovex S070 | <<locked>> | 94% | 58,334 psi | 90% | 2710 fps | 99.8% |
| Lovex S071ᴾ | <<locked>> | 100% | 43,613 psi | 67% | 2513 fps | 98.7% |
| Norma 201 | <<locked>> | 82% | 55,666 psi | 86% | 2612 fps | 100% |
| Norma 202 | <<locked>> | 82% | 56,188 psi | 86% | 2602 fps | 100% |
| Norma 203B | <<locked>> | 86% | 58,436 psi | 90% | 2700 fps | 100% |
| Norma 204 | <<locked>> | 94% | 57,145 psi | 88% | 2736 fps | 98.7% |
| Norma MRPᴾ | <<locked>> | 100% | 55,303 psi | 85% | 2812 fps | 99.6% |
| Norma URP | <<locked>> | 94% | 57,072 psi | 88% | 2730 fps | 100% |
| Ramshot Big Game | <<locked>> | 84% | 55,521 psi | 85% | 2680 fps | 100% |
| Ramshot Grandᴾ | <<locked>> | 100% | 50,937 psi | 78% | 2717 fps | 97.1% |
| Ramshot Hunter | <<locked>> | 94% | 55,927 psi | 86% | 2740 fps | 99.9% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 45,208 psi | 70% | 2598 fps | 97.5% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,188 psi | 57% | 1663 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 86% | 56,463 psi | 87% | 2667 fps | 99.8% |
| ReloadSwiss RS 52 | <<locked>> | 82% | 56,449 psi | 87% | 2730 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 88% | 56,304 psi | 87% | 2762 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 94% | 58,189 psi | 90% | 2769 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 94% | 56,652 psi | 87% | 2795 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 41,742 psi | 64% | 2618 fps | 97.6% |
| Rottweil R 902 | <<locked>> | 84% | 56,246 psi | 87% | 2612 fps | 100% |
| Rottweil R 903 | <<locked>> | 88% | 55,999 psi | 86% | 2654 fps | 100% |
| Rottweil R 904 | <<locked>> | 98% | 57,450 psi | 88% | 2710 fps | 97.9% |
| Rottweil R 905ᴾ | <<locked>> | 100% | 57,943 psi | 89% | 2766 fps | 99.1% |
| Rottweil R 907 | <<locked>> | 90% | 55,274 psi | 85% | 2648 fps | 99.2% |
| Shooters World Long Rifle | <<locked>> | 92% | 57,174 psi | 88% | 2671 fps | 100% |
| Shooters World Match Rifle | <<locked>> | 82% | 57,232 psi | 88% | 2638 fps | 100% |
| Shooters World Precision | <<locked>> | 86% | 57,740 psi | 89% | 2648 fps | 100% |
| Shooters World SW4350 | <<locked>> | 94% | 58,334 psi | 90% | 2710 fps | 99.8% |
| SNPE Vectan SP 11 | <<locked>> | 88% | 57,522 psi | 88% | 2713 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 82% | 57,986 psi | 89% | 2671 fps | 100% |
| SNPE Vectan SP 9 | <<locked>> | 82% | 55,143 psi | 85% | 2638 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 82% | 56,449 psi | 87% | 2543 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 88% | 57,174 psi | 88% | 2543 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 92% | 56,971 psi | 88% | 2628 fps | 99.6% |
| SNPE Vectan Tubal 8000ᴾ | <<locked>> | 100% | 57,435 psi | 88% | 2762 fps | 99% |
| Somchem S335 | <<locked>> | 82% | 56,144 psi | 86% | 2539 fps | 100% |
| Somchem S341 | <<locked>> | 82% | 57,754 psi | 89% | 2657 fps | 100% |
| Somchem S355 | <<locked>> | 88% | 56,014 psi | 86% | 2651 fps | 100% |
| Somchem S361 | <<locked>> | 96% | 55,550 psi | 85% | 2654 fps | 96.8% |
| Somchem S365 | <<locked>> | 96% | 56,289 psi | 87% | 2730 fps | 100% |
| Somchem S385ᴾ | <<locked>> | 100% | 58,566 psi | 90% | 2743 fps | 99.5% |
| Vihtavuori N133 | <<locked>> | 82% | 56,956 psi | 88% | 2523 fps | 100% |
| Vihtavuori N135 | <<locked>> | 84% | 56,434 psi | 87% | 2566 fps | 100% |
| Vihtavuori N140 | <<locked>> | 84% | 56,637 psi | 87% | 2582 fps | 100% |
| Vihtavuori N150 | <<locked>> | 90% | 57,305 psi | 88% | 2628 fps | 100% |
| Vihtavuori N160 | <<locked>> | 92% | 55,796 psi | 86% | 2677 fps | 100% |
| Vihtavuori N165ᴾ | <<locked>> | 100% | 50,589 psi | 78% | 2618 fps | 98.3% |
| Vihtavuori N540 | <<locked>> | 86% | 58,479 psi | 90% | 2631 fps | 100% |
| Vihtavuori N550 | <<locked>> | 94% | 58,349 psi | 90% | 2730 fps | 100% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 55,056 psi | 85% | 2740 fps | 100% |
| Vihtavuori N560ᴾ | <<locked>> | 100% | 55,724 psi | 86% | 2802 fps | 97.4% |
| Winchester 6.5 StaBALL | <<locked>> | 92% | 55,143 psi | 85% | 2644 fps | 100% |
| Winchester 760 | <<locked>> | 92% | 57,029 psi | 88% | 2746 fps | 99.7% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 44,353 psi | 68% | 2723 fps | 100% |
| Winchester StaBALL Match | <<locked>> | 82% | 55,317 psi | 85% | 2648 fps | 100% |
| Winchester Supreme 780ᴾ | <<locked>> | 100% | 54,810 psi | 84% | 2684 fps | 98.5% |
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% | 50,734 psi | 78% | 2497 fps | 100% |
| Accurate 2700 | <<locked>> | 80% | 48,588 psi | 75% | 2510 fps | 98.1% |
| Accurate 3100 | <<locked>> | 86% | 32,750 psi | 50% | 2297 fps | 95.7% |
| Accurate 4064 | <<locked>> | 80% | 48,051 psi | 74% | 2507 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 36,318 psi | 56% | 2385 fps | 98.5% |
| Accurate High Country | <<locked>> | 92% | 43,381 psi | 67% | 2612 fps | 95.2% |
| Accurate MAGPRO | <<locked>> | 98% | 50,575 psi | 78% | 2726 fps | 95.6% |
| ADI AR 2206H | <<locked>> | 80% | 53,258 psi | 82% | 2615 fps | 100% |
| ADI AR 2208 | <<locked>> | 80% | 45,252 psi | 70% | 2480 fps | 99.9% |
| ADI AR 2209 | <<locked>> | 88% | 40,379 psi | 62% | 2470 fps | 95.2% |
| ADI AR 2213 | <<locked>> | 96% | 46,572 psi | 72% | 2618 fps | 95.5% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 49,777 psi | 77% | 2680 fps | 100% |
| Alliant Power Pro Varmint | <<locked>> | 88% | 40,553 psi | 62% | 2477 fps | 95.4% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 45,745 psi | 70% | 2503 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 48,762 psi | 75% | 2569 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 80% | 35,694 psi | 55% | 2395 fps | 98.6% |
| Alliant Reloder-17 | 46.3 gr | 80% | 40,234 psi | 62% | 2513 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 88% | 40,118 psi | 62% | 2470 fps | 95.3% |
| Alliant Reloder-22 | <<locked>> | 92% | 39,987 psi | 62% | 2513 fps | 95.4% |
| Alliant Reloder-23 | <<locked>> | 80% | 26,136 psi | 40% | 2175 fps | 96.5% |
| Alliant Reloder-25 | <<locked>> | 90% | 31,401 psi | 48% | 2333 fps | 95.5% |
| Alliant Reloder-26 | <<locked>> | 82% | 29,530 psi | 45% | 2323 fps | 95.6% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 53,069 psi | 82% | 2635 fps | 100% |
| Bofors RP15 | <<locked>> | 94% | 39,450 psi | 61% | 2500 fps | 95.1% |
| Bofors RP3 | <<locked>> | 80% | 45,977 psi | 71% | 2516 fps | 100% |
| Bofors RP5 | <<locked>> | 92% | 39,987 psi | 62% | 2513 fps | 95.4% |
| Bofors RP7 | <<locked>> | 80% | 40,596 psi | 62% | 2398 fps | 96.5% |
| Hodgdon H380 | <<locked>> | 80% | 46,441 psi | 71% | 2530 fps | 99.6% |
| Hodgdon H414 | 45.3 gr | 80% | 38,392 psi | 59% | 2431 fps | 96.6% |
| Hodgdon H4350 | <<locked>> | 80% | 41,336 psi | 64% | 2448 fps | 96% |
| Hodgdon H4831 | <<locked>> | 96% | 50,053 psi | 77% | 2625 fps | 95.7% |
| Hodgdon H4831 SC | <<locked>> | 96% | 48,863 psi | 75% | 2605 fps | 95.4% |
| Hodgdon H4895 | <<locked>> | 80% | 53,838 psi | 83% | 2621 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 33,199 psi | 51% | 2297 fps | 99.1% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 50,517 psi | 78% | 2612 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 98% | 39,436 psi | 61% | 2566 fps | 95.5% |
| Hodgdon Superformance | <<locked>> | 80% | 37,202 psi | 57% | 2438 fps | 95.7% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,253 psi | 42% | 1450 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 51,576 psi | 79% | 2579 fps | 100% |
| IMR 3031 | <<locked>> | 80% | 54,795 psi | 84% | 2602 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 47,601 psi | 73% | 2510 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 80% | 50,024 psi | 77% | 2543 fps | 98.9% |
| IMR 4350 | <<locked>> | 80% | 36,318 psi | 56% | 2333 fps | 95.2% |
| IMR 4451 Enduron | <<locked>> | 80% | 41,989 psi | 65% | 2428 fps | 97.3% |
| IMR 4831 | <<locked>> | 80% | 35,172 psi | 54% | 2346 fps | 98.3% |
| IMR 4895 | <<locked>> | 80% | 50,038 psi | 77% | 2592 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 94% | 48,834 psi | 75% | 2569 fps | 95.7% |
| IMR 7828 SSC | <<locked>> | 96% | 44,512 psi | 68% | 2592 fps | 95% |
| Lovex D073.6 | <<locked>> | 80% | 53,679 psi | 83% | 2592 fps | 100% |
| Lovex S060 | <<locked>> | 80% | 52,257 psi | 80% | 2546 fps | 100% |
| Lovex S062 | <<locked>> | 80% | 47,819 psi | 74% | 2507 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 39,624 psi | 61% | 2385 fps | 98.1% |
| Lovex S070 | <<locked>> | 80% | 37,898 psi | 58% | 2369 fps | 96.6% |
| Lovex S071 | <<locked>> | 90% | 31,792 psi | 49% | 2274 fps | 95.3% |
| Norma 201 | <<locked>> | 80% | 52,286 psi | 80% | 2566 fps | 100% |
| Norma 202 | <<locked>> | 80% | 52,779 psi | 81% | 2559 fps | 100% |
| Norma 203B | <<locked>> | 80% | 48,167 psi | 74% | 2556 fps | 100% |
| Norma 204 | <<locked>> | 84% | 40,857 psi | 63% | 2464 fps | 95.3% |
| Norma MRP | <<locked>> | 88% | 36,724 psi | 56% | 2474 fps | 95.9% |
| Norma URP | <<locked>> | 80% | 36,390 psi | 56% | 2385 fps | 98.4% |
| Ramshot Big Game | <<locked>> | 80% | 48,370 psi | 74% | 2579 fps | 100% |
| Ramshot Grand | <<locked>> | 96% | 44,222 psi | 68% | 2598 fps | 95.3% |
| Ramshot Hunter | <<locked>> | 80% | 35,215 psi | 54% | 2372 fps | 96.5% |
| Ramshot Magnum | <<locked>> | 96% | 39,262 psi | 60% | 2484 fps | 95.8% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,789 psi | 43% | 1486 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 46,412 psi | 71% | 2510 fps | 98.8% |
| ReloadSwiss RS 52 | <<locked>> | 80% | 52,866 psi | 81% | 2680 fps | 100% |
| ReloadSwiss RS 60 | 46.3 gr | 80% | 42,743 psi | 66% | 2559 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 36,187 psi | 56% | 2405 fps | 98.2% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 35,143 psi | 54% | 2408 fps | 97.5% |
| ReloadSwiss RS 76 | <<locked>> | 96% | 36,332 psi | 56% | 2490 fps | 95.4% |
| Rottweil R 902 | <<locked>> | 80% | 49,893 psi | 77% | 2523 fps | 100% |
| Rottweil R 903 | <<locked>> | 80% | 43,453 psi | 67% | 2467 fps | 100% |
| Rottweil R 904 | <<locked>> | 90% | 44,788 psi | 69% | 2507 fps | 95.3% |
| Rottweil R 905 | <<locked>> | 88% | 38,986 psi | 60% | 2451 fps | 95.1% |
| Rottweil R 907 | <<locked>> | 80% | 40,596 psi | 62% | 2398 fps | 96.5% |
| Shooters World Long Rifle | <<locked>> | 80% | 39,624 psi | 61% | 2385 fps | 98.1% |
| Shooters World Match Rifle | <<locked>> | 80% | 53,679 psi | 83% | 2592 fps | 100% |
| Shooters World Precision | <<locked>> | 80% | 47,819 psi | 74% | 2507 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 37,898 psi | 58% | 2369 fps | 96.6% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 44,440 psi | 68% | 2520 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 80% | 54,418 psi | 84% | 2625 fps | 100% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 51,851 psi | 80% | 2592 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 52,953 psi | 81% | 2497 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 44,701 psi | 69% | 2379 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 38,638 psi | 59% | 2329 fps | 96.6% |
| SNPE Vectan Tubal 8000 | <<locked>> | 88% | 38,609 psi | 59% | 2444 fps | 95% |
| Somchem S335 | <<locked>> | 80% | 52,823 psi | 81% | 2500 fps | 100% |
| Somchem S341 | <<locked>> | 80% | 53,983 psi | 83% | 2608 fps | 100% |
| Somchem S355 | <<locked>> | 80% | 43,772 psi | 67% | 2467 fps | 100% |
| Somchem S361 | <<locked>> | 92% | 48,849 psi | 75% | 2552 fps | 95.4% |
| Somchem S365 | <<locked>> | 80% | 32,764 psi | 50% | 2343 fps | 99.8% |
| Somchem S385 | <<locked>> | 86% | 37,231 psi | 57% | 2388 fps | 95.5% |
| Vihtavuori N133 | <<locked>> | 80% | 53,447 psi | 82% | 2480 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 49,850 psi | 77% | 2484 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 50,256 psi | 77% | 2500 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 41,829 psi | 64% | 2405 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 37,594 psi | 58% | 2379 fps | 98.6% |
| Vihtavuori N165 | <<locked>> | 92% | 39,015 psi | 60% | 2418 fps | 95.6% |
| Vihtavuori N540 | <<locked>> | 80% | 48,385 psi | 74% | 2497 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 37,144 psi | 57% | 2385 fps | 98.3% |
| Vihtavuori N555 | <<locked>> | 80% | 28,645 psi | 44% | 2244 fps | 96.6% |
| Vihtavuori N560 | <<locked>> | 96% | 48,660 psi | 75% | 2687 fps | 95.8% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 36,811 psi | 57% | 2352 fps | 99.8% |
| Winchester 760 | <<locked>> | 80% | 38,392 psi | 59% | 2431 fps | 96.6% |
| Winchester StaBALL HD | <<locked>> | 82% | 24,526 psi | 38% | 2198 fps | 96.2% |
| Winchester StaBALL Match | <<locked>> | 80% | 51,648 psi | 79% | 2595 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 92% | 41,640 psi | 64% | 2470 fps | 95.7% |
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 108 powders for .280 Ackley Improved loaded with the .284 | 170gr | Hammer HHT. Alliant Reloder-26 delivers the highest muzzle velocity at 2,851 fps; across all powders the maximum-charge window runs from 1,624 fps to 2,851 fps. Accurate 3100 gives the best case fill at 100 %, and 108 of the 108 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 170.0 gr projectile in 0.284" calls for a 1:8.0 twist; slower twists will usually not stabilise this weight. Accurate 3100, Accurate High Country, Accurate MAGPRO 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-17, ReloadSwiss RS 60, Hodgdon H414 rank at the top here: for .280 Ackley Improved with the .284 | 170gr | Hammer HHT 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.