Load Specifications
Bullet Manufacturer:Peregrine
Bullet Weight:166 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:1:11.0
Load data in caliber .280 Ackley Improved with .284 | 166gr | Peregrine VRG-2 bullet and 100 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Alliant Reloder-26, ReloadSwiss RS 70 and Alliant Reloder-17.
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% | 56,115 psi | 86% | 2628 fps | 100% |
| Accurate 2700 | <<locked>> | 84% | 57,711 psi | 89% | 2713 fps | 99.5% |
| Accurate 3100ᴾ | <<locked>> | 100% | 55,564 psi | 85% | 2756 fps | 99.9% |
| Accurate 4064 | <<locked>> | 84% | 56,724 psi | 87% | 2687 fps | 100% |
| Accurate 4350 | <<locked>> | 92% | 57,943 psi | 89% | 2802 fps | 100% |
| Accurate MAGPROᴾ | <<locked>> | 100% | 58,189 psi | 90% | 2904 fps | 97.6% |
| ADI AR 2208 | <<locked>> | 86% | 56,797 psi | 87% | 2720 fps | 100% |
| ADI AR 2209 | <<locked>> | 96% | 55,259 psi | 85% | 2799 fps | 98.8% |
| ADI AR 2213ᴾ | <<locked>> | 100% | 56,652 psi | 87% | 2854 fps | 98.2% |
| Alliant Power Pro 2000-MR | <<locked>> | 82% | 56,710 psi | 87% | 2844 fps | 100% |
| Alliant Power Pro Varmint | <<locked>> | 96% | 55,361 psi | 85% | 2795 fps | 98.9% |
| Alliant Power Pro Varmint | <<locked>> | 96% | 55,361 psi | 85% | 2795 fps | 98.9% |
| Alliant Reloder- TS 15.5 | <<locked>> | 86% | 57,725 psi | 89% | 2743 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 84% | 58,117 psi | 89% | 2766 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 92% | 55,042 psi | 85% | 2802 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 88% | 56,550 psi | 87% | 2825 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 98% | 58,204 psi | 90% | 2838 fps | 99.2% |
| Alliant Reloder-22ᴾ | <<locked>> | 100% | 55,666 psi | 86% | 2844 fps | 99.1% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 52,518 psi | 81% | 2769 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 45,513 psi | 70% | 2710 fps | 99.8% |
| Alliant Reloder-26 | <<locked>> | 98% | 56,826 psi | 87% | 2913 fps | 100% |
| Bofors RP15ᴾ | <<locked>> | 100% | 50,981 psi | 78% | 2772 fps | 98.3% |
| Bofors RP3 | <<locked>> | 86% | 58,595 psi | 90% | 2756 fps | 100% |
| Bofors RP5ᴾ | <<locked>> | 100% | 55,666 psi | 86% | 2844 fps | 99.1% |
| Bofors RP7 | <<locked>> | 90% | 57,972 psi | 89% | 2753 fps | 99.6% |
| Hodgdon H1000ᴾ | <<locked>> | 100% | 45,107 psi | 69% | 2651 fps | 96.4% |
| Hodgdon H380 | <<locked>> | 84% | 55,448 psi | 85% | 2730 fps | 100% |
| Hodgdon H414 | <<locked>> | 90% | 56,449 psi | 87% | 2802 fps | 99.8% |
| Hodgdon H4350 | <<locked>> | 88% | 56,231 psi | 87% | 2766 fps | 99.1% |
| Hodgdon H4831 | <<locked>> | 98% | 56,608 psi | 87% | 2792 fps | 97.5% |
| Hodgdon H4831 SC | <<locked>> | 98% | 55,651 psi | 86% | 2779 fps | 97.3% |
| Hodgdon Hybrid 100V | <<locked>> | 94% | 55,259 psi | 85% | 2726 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 82% | 56,956 psi | 88% | 2762 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 44,657 psi | 69% | 2749 fps | 97.9% |
| Hodgdon Superformance | <<locked>> | 90% | 56,898 psi | 88% | 2844 fps | 99.7% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,564 psi | 56% | 1683 fps | 100% |
| Hodgdon VARGET | <<locked>> | 82% | 57,392 psi | 88% | 2723 fps | 100% |
| IMR 4064 | <<locked>> | 84% | 56,449 psi | 87% | 2707 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 82% | 55,288 psi | 85% | 2690 fps | 99.6% |
| IMR 4350 | <<locked>> | 92% | 55,564 psi | 85% | 2740 fps | 99.4% |
| IMR 4451 Enduron | <<locked>> | 88% | 55,999 psi | 86% | 2726 fps | 99.6% |
| IMR 4831 | <<locked>> | 94% | 58,175 psi | 89% | 2789 fps | 100% |
| IMR 4895 | <<locked>> | 82% | 55,680 psi | 86% | 2740 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 98% | 58,204 psi | 90% | 2782 fps | 97.9% |
| IMR 7828 SSCᴾ | <<locked>> | 100% | 53,983 psi | 83% | 2825 fps | 97.8% |
| Lovex S060 | <<locked>> | 82% | 57,783 psi | 89% | 2687 fps | 100% |
| Lovex S062 | <<locked>> | 84% | 56,536 psi | 87% | 2697 fps | 100% |
| Lovex S065 | <<locked>> | 90% | 56,101 psi | 86% | 2723 fps | 100% |
| Lovex S070 | <<locked>> | 92% | 57,566 psi | 89% | 2766 fps | 99.9% |
| Lovex S071ᴾ | <<locked>> | 100% | 45,992 psi | 71% | 2612 fps | 99.2% |
| Norma 201 | <<locked>> | 82% | 57,769 psi | 89% | 2703 fps | 100% |
| Norma 202 | <<locked>> | 82% | 58,450 psi | 90% | 2697 fps | 100% |
| Norma 203B | <<locked>> | 84% | 57,406 psi | 88% | 2753 fps | 100% |
| Norma 204 | <<locked>> | 92% | 56,420 psi | 87% | 2792 fps | 98.9% |
| Norma MRP | <<locked>> | 98% | 55,303 psi | 85% | 2871 fps | 99.7% |
| Norma URP | <<locked>> | 92% | 56,594 psi | 87% | 2785 fps | 100% |
| Ramshot Big Game | <<locked>> | 84% | 58,450 psi | 90% | 2782 fps | 100% |
| Ramshot Grandᴾ | <<locked>> | 100% | 54,331 psi | 84% | 2841 fps | 98.2% |
| Ramshot Hunter | <<locked>> | 92% | 55,332 psi | 85% | 2792 fps | 99.9% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 48,515 psi | 75% | 2720 fps | 98.6% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,260 psi | 57% | 1726 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 84% | 55,274 psi | 85% | 2717 fps | 99.8% |
| ReloadSwiss RS 60 | <<locked>> | 86% | 55,956 psi | 86% | 2815 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 92% | 57,769 psi | 89% | 2825 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 92% | 56,362 psi | 87% | 2854 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 44,367 psi | 68% | 2740 fps | 98.7% |
| Rottweil R 902 | <<locked>> | 84% | 58,247 psi | 90% | 2703 fps | 100% |
| Rottweil R 903 | <<locked>> | 88% | 58,798 psi | 90% | 2756 fps | 100% |
| Rottweil R 904 | <<locked>> | 96% | 56,927 psi | 88% | 2769 fps | 98.2% |
| Rottweil R 905 | <<locked>> | 98% | 57,653 psi | 89% | 2828 fps | 99.2% |
| Rottweil R 907 | <<locked>> | 90% | 57,972 psi | 89% | 2753 fps | 99.6% |
| Shooters World Long Rifle | <<locked>> | 90% | 56,101 psi | 86% | 2723 fps | 100% |
| Shooters World Precision | <<locked>> | 84% | 56,536 psi | 87% | 2697 fps | 100% |
| Shooters World SW4350 | <<locked>> | 92% | 57,566 psi | 89% | 2766 fps | 99.9% |
| SNPE Vectan SP 11 | <<locked>> | 86% | 57,014 psi | 88% | 2769 fps | 100% |
| SNPE Vectan SP 9 | <<locked>> | 82% | 57,769 psi | 89% | 2740 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 82% | 58,639 psi | 90% | 2635 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 86% | 55,956 psi | 86% | 2592 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 90% | 55,753 psi | 86% | 2680 fps | 99.7% |
| SNPE Vectan Tubal 8000 | <<locked>> | 98% | 57,174 psi | 88% | 2825 fps | 99.2% |
| Somchem S335 | <<locked>> | 82% | 58,175 psi | 89% | 2631 fps | 100% |
| Somchem S355 | <<locked>> | 88% | 58,523 psi | 90% | 2749 fps | 100% |
| Somchem S361 | <<locked>> | 96% | 58,740 psi | 90% | 2766 fps | 97.8% |
| Somchem S365 | <<locked>> | 94% | 56,130 psi | 86% | 2785 fps | 100% |
| Somchem S385 | <<locked>> | 98% | 58,175 psi | 89% | 2802 fps | 99.6% |
| Vihtavuori N135 | <<locked>> | 82% | 55,579 psi | 86% | 2618 fps | 100% |
| Vihtavuori N140 | <<locked>> | 82% | 55,608 psi | 86% | 2635 fps | 100% |
| Vihtavuori N150 | <<locked>> | 88% | 56,405 psi | 87% | 2677 fps | 100% |
| Vihtavuori N160 | <<locked>> | 92% | 58,813 psi | 90% | 2779 fps | 100% |
| Vihtavuori N165ᴾ | <<locked>> | 100% | 53,650 psi | 83% | 2726 fps | 99% |
| Vihtavuori N540 | <<locked>> | 84% | 57,421 psi | 88% | 2677 fps | 100% |
| Vihtavuori N550 | <<locked>> | 92% | 57,696 psi | 89% | 2785 fps | 100% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 58,523 psi | 90% | 2841 fps | 100% |
| Vihtavuori N560 | <<locked>> | 98% | 55,506 psi | 85% | 2864 fps | 97.7% |
| Vihtavuori N565ᴾ | <<locked>> | 100% | 47,253 psi | 73% | 2713 fps | 96.2% |
| Winchester 6.5 StaBALL | <<locked>> | 92% | 58,494 psi | 90% | 2746 fps | 100% |
| Winchester 760 | <<locked>> | 90% | 56,724 psi | 87% | 2808 fps | 99.8% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 48,051 psi | 74% | 2838 fps | 100% |
| Winchester StaBALL Match | <<locked>> | 82% | 57,841 psi | 89% | 2743 fps | 100% |
| Winchester Supreme 780ᴾ | <<locked>> | 100% | 58,523 psi | 90% | 2799 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 2495 | <<locked>> | 80% | 52,475 psi | 81% | 2582 fps | 100% |
| Accurate 2700 | <<locked>> | 80% | 50,372 psi | 77% | 2605 fps | 98.7% |
| Accurate 3100 | <<locked>> | 84% | 32,024 psi | 49% | 2329 fps | 95.7% |
| Accurate 4064 | <<locked>> | 80% | 49,821 psi | 77% | 2592 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 38,058 psi | 59% | 2474 fps | 99% |
| Accurate MAGPRO | <<locked>> | 94% | 47,021 psi | 72% | 2723 fps | 95.1% |
| ADI AR 2208 | <<locked>> | 80% | 47,195 psi | 73% | 2575 fps | 100% |
| ADI AR 2209 | <<locked>> | 86% | 39,697 psi | 61% | 2520 fps | 95.3% |
| ADI AR 2213 | <<locked>> | 94% | 46,122 psi | 71% | 2674 fps | 95.8% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 52,736 psi | 81% | 2789 fps | 100% |
| Alliant Power Pro Varmint | <<locked>> | 86% | 39,900 psi | 61% | 2520 fps | 95.5% |
| Alliant Power Pro Varmint | <<locked>> | 86% | 39,900 psi | 61% | 2520 fps | 95.5% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 47,906 psi | 74% | 2602 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 50,908 psi | 78% | 2664 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 80% | 37,333 psi | 57% | 2490 fps | 99.2% |
| Alliant Reloder-17 | 50.7 gr | 80% | 42,424 psi | 65% | 2608 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 86% | 39,479 psi | 61% | 2513 fps | 95.4% |
| Alliant Reloder-22 | <<locked>> | 90% | 39,639 psi | 61% | 2562 fps | 95.6% |
| Alliant Reloder-23 | <<locked>> | 80% | 27,108 psi | 42% | 2254 fps | 97.2% |
| Alliant Reloder-25 | <<locked>> | 88% | 30,835 psi | 47% | 2372 fps | 95.6% |
| Alliant Reloder-26 | 52 gr | 80% | 28,993 psi | 45% | 2359 fps | 95.6% |
| Bofors RP15 | <<locked>> | 92% | 39,102 psi | 60% | 2549 fps | 95.3% |
| Bofors RP3 | <<locked>> | 80% | 48,138 psi | 74% | 2608 fps | 100% |
| Bofors RP5 | <<locked>> | 90% | 39,639 psi | 61% | 2562 fps | 95.6% |
| Bofors RP7 | <<locked>> | 80% | 42,076 psi | 65% | 2490 fps | 97.2% |
| Hodgdon H1000 | <<locked>> | 98% | 42,163 psi | 65% | 2592 fps | 95.4% |
| Hodgdon H380 | <<locked>> | 80% | 48,443 psi | 75% | 2625 fps | 99.9% |
| Hodgdon H414 | <<locked>> | 80% | 40,263 psi | 62% | 2526 fps | 97.4% |
| Hodgdon H4350 | <<locked>> | 80% | 43,337 psi | 67% | 2549 fps | 96.9% |
| Hodgdon H4831 | <<locked>> | 92% | 46,325 psi | 71% | 2628 fps | 95.2% |
| Hodgdon H4831 SC | <<locked>> | 94% | 48,414 psi | 74% | 2664 fps | 95.8% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 34,853 psi | 54% | 2388 fps | 99.5% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 53,142 psi | 82% | 2710 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 96% | 38,957 psi | 60% | 2618 fps | 95.9% |
| Hodgdon Superformance | <<locked>> | 80% | 39,218 psi | 60% | 2539 fps | 96.7% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,238 psi | 42% | 1503 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 53,853 psi | 83% | 2674 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 49,617 psi | 76% | 2605 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 80% | 51,895 psi | 80% | 2638 fps | 99.3% |
| IMR 4350 | <<locked>> | 80% | 37,927 psi | 58% | 2425 fps | 96.1% |
| IMR 4451 Enduron | <<locked>> | 80% | 43,801 psi | 67% | 2523 fps | 98% |
| IMR 4831 | <<locked>> | 80% | 36,637 psi | 56% | 2431 fps | 98.7% |
| IMR 4895 | <<locked>> | 80% | 52,257 psi | 80% | 2687 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 90% | 45,194 psi | 70% | 2569 fps | 95.1% |
| IMR 7828 SSC | <<locked>> | 94% | 43,918 psi | 68% | 2644 fps | 95.3% |
| Lovex S060 | <<locked>> | 80% | 54,259 psi | 83% | 2638 fps | 100% |
| Lovex S062 | <<locked>> | 80% | 49,777 psi | 77% | 2602 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 41,075 psi | 63% | 2474 fps | 98.6% |
| Lovex S070 | <<locked>> | 80% | 39,276 psi | 60% | 2454 fps | 97.3% |
| Lovex S071 | <<locked>> | 88% | 31,111 psi | 48% | 2306 fps | 95.3% |
| Norma 201 | <<locked>> | 80% | 54,201 psi | 83% | 2654 fps | 100% |
| Norma 202 | <<locked>> | 80% | 55,129 psi | 85% | 2654 fps | 100% |
| Norma 203B | <<locked>> | 80% | 50,241 psi | 77% | 2648 fps | 100% |
| Norma 204 | <<locked>> | 82% | 40,089 psi | 62% | 2507 fps | 95.4% |
| Norma MRP | <<locked>> | 86% | 36,056 psi | 55% | 2513 fps | 95.9% |
| Norma URP | <<locked>> | 80% | 38,014 psi | 58% | 2470 fps | 98.9% |
| Ramshot Big Game | <<locked>> | 80% | 50,937 psi | 78% | 2677 fps | 100% |
| Ramshot Grand | <<locked>> | 94% | 43,845 psi | 67% | 2657 fps | 95.7% |
| Ramshot Hunter | <<locked>> | 80% | 36,869 psi | 57% | 2461 fps | 97.2% |
| Ramshot Magnum | <<locked>> | 92% | 36,100 psi | 56% | 2474 fps | 95% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,717 psi | 43% | 1539 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 48,501 psi | 75% | 2612 fps | 99.3% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 45,121 psi | 69% | 2654 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 38,145 psi | 59% | 2497 fps | 98.8% |
| ReloadSwiss RS 70 | 51.5 gr | 80% | 36,898 psi | 57% | 2507 fps | 98.3% |
| ReloadSwiss RS 76 | <<locked>> | 94% | 35,795 psi | 55% | 2539 fps | 95.7% |
| Rottweil R 902 | <<locked>> | 80% | 51,547 psi | 79% | 2612 fps | 100% |
| Rottweil R 903 | <<locked>> | 80% | 45,165 psi | 69% | 2559 fps | 100% |
| Rottweil R 904 | <<locked>> | 88% | 43,903 psi | 68% | 2552 fps | 95.4% |
| Rottweil R 905 | <<locked>> | 86% | 38,479 psi | 59% | 2497 fps | 95.3% |
| Rottweil R 907 | <<locked>> | 80% | 42,076 psi | 65% | 2490 fps | 97.2% |
| Shooters World Long Rifle | <<locked>> | 80% | 41,075 psi | 63% | 2474 fps | 98.6% |
| Shooters World Precision | <<locked>> | 80% | 49,777 psi | 77% | 2602 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 39,276 psi | 60% | 2454 fps | 97.3% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 46,543 psi | 72% | 2612 fps | 100% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 54,027 psi | 83% | 2687 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 54,926 psi | 85% | 2589 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 46,514 psi | 72% | 2464 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 40,074 psi | 62% | 2418 fps | 97.3% |
| SNPE Vectan Tubal 8000 | <<locked>> | 86% | 38,116 psi | 59% | 2490 fps | 95.1% |
| Somchem S335 | <<locked>> | 80% | 54,723 psi | 84% | 2585 fps | 100% |
| Somchem S355 | <<locked>> | 80% | 45,542 psi | 70% | 2559 fps | 100% |
| Somchem S361 | <<locked>> | 90% | 47,935 psi | 74% | 2598 fps | 95.6% |
| Somchem S365 | <<locked>> | 80% | 34,534 psi | 53% | 2431 fps | 100% |
| Somchem S385 | <<locked>> | 84% | 36,448 psi | 56% | 2425 fps | 95.5% |
| Vihtavuori N135 | <<locked>> | 80% | 51,996 psi | 80% | 2572 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 52,170 psi | 80% | 2589 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 43,453 psi | 67% | 2487 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 39,378 psi | 61% | 2470 fps | 99.1% |
| Vihtavuori N165 | <<locked>> | 90% | 38,450 psi | 59% | 2461 fps | 95.8% |
| Vihtavuori N540 | <<locked>> | 80% | 50,401 psi | 78% | 2585 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 38,870 psi | 60% | 2474 fps | 98.9% |
| Vihtavuori N555 | <<locked>> | 80% | 29,994 psi | 46% | 2326 fps | 97.3% |
| Vihtavuori N560 | <<locked>> | 92% | 45,034 psi | 69% | 2680 fps | 95.2% |
| Vihtavuori N565 | <<locked>> | 98% | 43,932 psi | 68% | 2654 fps | 95.2% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 38,508 psi | 59% | 2444 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 40,495 psi | 62% | 2530 fps | 97.4% |
| Winchester StaBALL HD | <<locked>> | 80% | 23,772 psi | 37% | 2221 fps | 95.9% |
| Winchester StaBALL Match | <<locked>> | 80% | 54,288 psi | 84% | 2697 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 90% | 41,060 psi | 63% | 2520 fps | 95.9% |
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 100 powders for .280 Ackley Improved loaded with the .284 | 166gr | Peregrine VRG-2. Alliant Reloder-26 delivers the highest muzzle velocity at 2,913 fps; across all powders the maximum-charge window runs from 1,683 fps to 2,913 fps. Accurate 3100 gives the best case fill at 100 %, and 100 of the 100 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 166.0 gr projectile in 0.284" calls for a 1:11.0 twist; slower twists will usually not stabilise this weight. Accurate 3100, Accurate MAGPRO, ADI AR 2213 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, ReloadSwiss RS 70, Alliant Reloder-17 rank at the top here: for .280 Ackley Improved with the .284 | 166gr | Peregrine VRG-2 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.