Load Specifications
Bullet Manufacturer:TWENTY-NINE
Bullet Weight:180 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:1:7.5
Load data in caliber .280 Ackley Improved with .284 | 180gr | TWENTY-NINE ERTP bullet and 105 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 Accurate High Country.
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% | 55,869 psi | 86% | 2480 fps | 100% |
| Accurate 2700 | <<locked>> | 84% | 56,724 psi | 87% | 2556 fps | 99.5% |
| Accurate 3100ᴾ | <<locked>> | 100% | 54,331 psi | 84% | 2602 fps | 99.9% |
| Accurate 4064 | <<locked>> | 84% | 56,057 psi | 86% | 2533 fps | 100% |
| Accurate 4350 | <<locked>> | 92% | 56,898 psi | 88% | 2644 fps | 100% |
| Accurate High Country | <<locked>> | 98% | 55,724 psi | 86% | 2743 fps | 98.5% |
| Accurate MAGPROᴾ | <<locked>> | 100% | 56,608 psi | 87% | 2743 fps | 97.5% |
| ADI AR 2206H | <<locked>> | 82% | 58,320 psi | 90% | 2602 fps | 100% |
| ADI AR 2208 | <<locked>> | 86% | 55,912 psi | 86% | 2566 fps | 100% |
| ADI AR 2209 | <<locked>> | 98% | 57,754 psi | 89% | 2690 fps | 99.2% |
| ADI AR 2213ᴾ | <<locked>> | 100% | 55,085 psi | 85% | 2687 fps | 98% |
| Alliant Power Pro 2000-MR | <<locked>> | 82% | 55,230 psi | 85% | 2680 fps | 100% |
| Alliant Power Pro Varmint | <<locked>> | 98% | 57,493 psi | 88% | 2684 fps | 99.2% |
| Alliant Power Pro Varmint | <<locked>> | 98% | 57,493 psi | 88% | 2684 fps | 99.2% |
| Alliant Reloder- TS 15.5 | <<locked>> | 86% | 57,058 psi | 88% | 2589 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 84% | 57,072 psi | 88% | 2605 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 94% | 57,334 psi | 88% | 2690 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 88% | 54,926 psi | 85% | 2664 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 98% | 56,681 psi | 87% | 2677 fps | 99.2% |
| Alliant Reloder-22ᴾ | <<locked>> | 100% | 53,998 psi | 83% | 2684 fps | 99% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 51,271 psi | 79% | 2618 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 44,382 psi | 68% | 2556 fps | 99.7% |
| Alliant Reloder-26 | <<locked>> | 98% | 54,505 psi | 84% | 2746 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 82% | 58,320 psi | 90% | 2628 fps | 100% |
| Bofors RP15ᴾ | <<locked>> | 100% | 49,472 psi | 76% | 2612 fps | 98.3% |
| Bofors RP3 | <<locked>> | 86% | 57,798 psi | 89% | 2602 fps | 100% |
| Bofors RP5ᴾ | <<locked>> | 100% | 53,998 psi | 83% | 2684 fps | 99% |
| Bofors RP7 | <<locked>> | 90% | 57,058 psi | 88% | 2598 fps | 99.6% |
| Hodgdon H1000ᴾ | <<locked>> | 100% | 44,266 psi | 68% | 2500 fps | 96.4% |
| Hodgdon H380 | <<locked>> | 86% | 58,102 psi | 89% | 2621 fps | 100% |
| Hodgdon H414 | <<locked>> | 90% | 55,347 psi | 85% | 2648 fps | 99.8% |
| Hodgdon H4350 | <<locked>> | 90% | 58,581 psi | 90% | 2654 fps | 99.5% |
| Hodgdon H4831 | <<locked>> | 98% | 55,419 psi | 85% | 2638 fps | 97.5% |
| Hodgdon H4831 SCᴾ | <<locked>> | 100% | 57,827 psi | 89% | 2671 fps | 97.9% |
| Hodgdon Hybrid 100V | <<locked>> | 96% | 57,943 psi | 89% | 2618 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 82% | 55,724 psi | 86% | 2602 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 43,468 psi | 67% | 2592 fps | 97.8% |
| Hodgdon Superformance | <<locked>> | 90% | 55,216 psi | 85% | 2680 fps | 99.7% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,434 psi | 56% | 1572 fps | 100% |
| Hodgdon VARGET | <<locked>> | 82% | 56,536 psi | 87% | 2566 fps | 100% |
| IMR 4064 | <<locked>> | 84% | 55,637 psi | 86% | 2549 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 84% | 58,218 psi | 90% | 2585 fps | 99.9% |
| IMR 4350 | <<locked>> | 94% | 58,001 psi | 89% | 2628 fps | 99.7% |
| IMR 4451 Enduron | <<locked>> | 90% | 58,653 psi | 90% | 2621 fps | 99.9% |
| IMR 4831 | <<locked>> | 94% | 57,014 psi | 88% | 2631 fps | 100% |
| IMR 4895 | <<locked>> | 84% | 58,523 psi | 90% | 2631 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 98% | 57,072 psi | 88% | 2625 fps | 97.9% |
| IMR 7828 SSCᴾ | <<locked>> | 100% | 52,692 psi | 81% | 2664 fps | 97.7% |
| Lovex S060 | <<locked>> | 82% | 56,971 psi | 88% | 2530 fps | 100% |
| Lovex S062 | <<locked>> | 84% | 55,869 psi | 86% | 2543 fps | 100% |
| Lovex S065 | <<locked>> | 92% | 58,784 psi | 90% | 2615 fps | 100% |
| Lovex S070 | <<locked>> | 92% | 56,507 psi | 87% | 2608 fps | 99.9% |
| Lovex S071ᴾ | <<locked>> | 100% | 45,397 psi | 70% | 2474 fps | 99.3% |
| Norma 201 | <<locked>> | 82% | 57,203 psi | 88% | 2549 fps | 100% |
| Norma 202 | <<locked>> | 82% | 57,783 psi | 89% | 2543 fps | 100% |
| Norma 203B | <<locked>> | 84% | 56,362 psi | 87% | 2595 fps | 100% |
| Norma 204 | <<locked>> | 92% | 55,114 psi | 85% | 2631 fps | 98.8% |
| Norma MRPᴾ | <<locked>> | 100% | 57,450 psi | 88% | 2759 fps | 99.9% |
| Norma URP | <<locked>> | 92% | 55,274 psi | 85% | 2628 fps | 100% |
| Ramshot Big Game | <<locked>> | 84% | 57,203 psi | 88% | 2621 fps | 100% |
| Ramshot Grandᴾ | <<locked>> | 100% | 52,794 psi | 81% | 2677 fps | 98.1% |
| Ramshot Hunter | <<locked>> | 94% | 57,624 psi | 89% | 2680 fps | 100% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 47,297 psi | 73% | 2566 fps | 98.5% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,246 psi | 57% | 1614 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 86% | 58,030 psi | 89% | 2612 fps | 100% |
| ReloadSwiss RS 52 | <<locked>> | 82% | 58,436 psi | 90% | 2674 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 88% | 58,363 psi | 90% | 2703 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 92% | 56,681 psi | 87% | 2667 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 92% | 54,810 psi | 84% | 2694 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 43,366 psi | 67% | 2589 fps | 98.7% |
| Rottweil R 902 | <<locked>> | 84% | 57,841 psi | 89% | 2552 fps | 100% |
| Rottweil R 903 | <<locked>> | 88% | 57,986 psi | 89% | 2602 fps | 100% |
| Rottweil R 904 | <<locked>> | 96% | 55,666 psi | 86% | 2608 fps | 98.2% |
| Rottweil R 905 | <<locked>> | 98% | 55,985 psi | 86% | 2664 fps | 99.2% |
| Rottweil R 907 | <<locked>> | 90% | 57,058 psi | 88% | 2598 fps | 99.6% |
| Shooters World Long Rifle | <<locked>> | 92% | 58,784 psi | 90% | 2615 fps | 100% |
| Shooters World Precision | <<locked>> | 84% | 55,869 psi | 86% | 2543 fps | 100% |
| Shooters World SW4350 | <<locked>> | 92% | 56,507 psi | 87% | 2608 fps | 99.9% |
| SNPE Vectan SP 11 | <<locked>> | 86% | 55,680 psi | 86% | 2608 fps | 100% |
| SNPE Vectan SP 9 | <<locked>> | 82% | 56,840 psi | 87% | 2582 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 82% | 57,798 psi | 89% | 2477 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 88% | 58,755 psi | 90% | 2484 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 92% | 58,595 psi | 90% | 2575 fps | 99.9% |
| SNPE Vectan Tubal 8000 | <<locked>> | 98% | 55,564 psi | 85% | 2661 fps | 99.1% |
| Somchem S335 | <<locked>> | 82% | 57,653 psi | 89% | 2480 fps | 100% |
| Somchem S355 | <<locked>> | 88% | 57,899 psi | 89% | 2595 fps | 100% |
| Somchem S361 | <<locked>> | 96% | 57,551 psi | 89% | 2608 fps | 97.7% |
| Somchem S365 | <<locked>> | 96% | 58,581 psi | 90% | 2674 fps | 100% |
| Somchem S385 | <<locked>> | 98% | 56,710 psi | 87% | 2641 fps | 99.6% |
| Vihtavuori N133 | <<locked>> | 82% | 58,349 psi | 90% | 2461 fps | 100% |
| Vihtavuori N135 | <<locked>> | 84% | 58,088 psi | 89% | 2503 fps | 100% |
| Vihtavuori N140 | <<locked>> | 84% | 58,305 psi | 90% | 2523 fps | 100% |
| Vihtavuori N150 | <<locked>> | 88% | 55,564 psi | 85% | 2526 fps | 100% |
| Vihtavuori N160 | <<locked>> | 92% | 57,638 psi | 89% | 2621 fps | 100% |
| Vihtavuori N165ᴾ | <<locked>> | 100% | 52,315 psi | 80% | 2569 fps | 99% |
| Vihtavuori N540 | <<locked>> | 84% | 56,405 psi | 87% | 2523 fps | 100% |
| Vihtavuori N550 | <<locked>> | 92% | 56,652 psi | 87% | 2631 fps | 100% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 57,377 psi | 88% | 2687 fps | 100% |
| Vihtavuori N560ᴾ | <<locked>> | 100% | 57,740 psi | 89% | 2756 fps | 98.2% |
| Vihtavuori N565ᴾ | <<locked>> | 100% | 45,934 psi | 71% | 2562 fps | 96.1% |
| Winchester 6.5 StaBALL | <<locked>> | 92% | 57,159 psi | 88% | 2592 fps | 100% |
| Winchester 760 | <<locked>> | 90% | 55,347 psi | 85% | 2648 fps | 99.8% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 46,166 psi | 71% | 2680 fps | 100% |
| Winchester StaBALL Match | <<locked>> | 82% | 57,116 psi | 88% | 2589 fps | 100% |
| Winchester Supreme 780ᴾ | <<locked>> | 100% | 57,029 psi | 88% | 2641 fps | 99.1% |
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% | 52,315 psi | 80% | 2438 fps | 100% |
| Accurate 2700 | <<locked>> | 80% | 49,763 psi | 77% | 2457 fps | 98.7% |
| Accurate 3100 | <<locked>> | 82% | 29,689 psi | 46% | 2159 fps | 95.1% |
| Accurate 4064 | <<locked>> | 80% | 49,617 psi | 76% | 2448 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 37,739 psi | 58% | 2343 fps | 99.2% |
| Accurate High Country | 51.1 gr | 90% | 42,090 psi | 65% | 2516 fps | 95.6% |
| Accurate MAGPRO | <<locked>> | 94% | 45,818 psi | 70% | 2572 fps | 95.1% |
| ADI AR 2206H | <<locked>> | 80% | 54,766 psi | 84% | 2556 fps | 100% |
| ADI AR 2208 | <<locked>> | 80% | 46,775 psi | 72% | 2434 fps | 100% |
| ADI AR 2209 | <<locked>> | 86% | 39,218 psi | 60% | 2382 fps | 95.5% |
| ADI AR 2213 | <<locked>> | 94% | 45,179 psi | 70% | 2523 fps | 95.8% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 51,648 psi | 79% | 2631 fps | 100% |
| Alliant Power Pro Varmint | <<locked>> | 86% | 39,204 psi | 60% | 2382 fps | 95.6% |
| Alliant Power Pro Varmint | <<locked>> | 86% | 39,204 psi | 60% | 2382 fps | 95.6% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 47,152 psi | 73% | 2451 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 50,299 psi | 77% | 2513 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 80% | 36,854 psi | 57% | 2352 fps | 99.3% |
| Alliant Reloder-17 | <<locked>> | 80% | 41,771 psi | 64% | 2467 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 86% | 38,841 psi | 60% | 2375 fps | 95.6% |
| Alliant Reloder-22 | <<locked>> | 90% | 38,870 psi | 60% | 2421 fps | 95.8% |
| Alliant Reloder-23 | <<locked>> | 80% | 27,079 psi | 42% | 2142 fps | 97.7% |
| Alliant Reloder-25 | <<locked>> | 86% | 28,819 psi | 44% | 2201 fps | 95% |
| Alliant Reloder-26 | 46.8 gr | 80% | 28,732 psi | 44% | 2241 fps | 96.1% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 54,839 psi | 84% | 2582 fps | 100% |
| Bofors RP15 | <<locked>> | 92% | 38,363 psi | 59% | 2408 fps | 95.4% |
| Bofors RP3 | <<locked>> | 80% | 47,529 psi | 73% | 2464 fps | 100% |
| Bofors RP5 | <<locked>> | 90% | 38,870 psi | 60% | 2421 fps | 95.8% |
| Bofors RP7 | <<locked>> | 80% | 41,771 psi | 64% | 2352 fps | 97.4% |
| Hodgdon H1000 | <<locked>> | 98% | 41,452 psi | 64% | 2448 fps | 95.5% |
| Hodgdon H380 | <<locked>> | 80% | 47,892 psi | 74% | 2477 fps | 99.9% |
| Hodgdon H414 | <<locked>> | 80% | 39,827 psi | 61% | 2388 fps | 97.6% |
| Hodgdon H4350 | <<locked>> | 80% | 42,670 psi | 66% | 2402 fps | 97% |
| Hodgdon H4831 | <<locked>> | 92% | 45,426 psi | 70% | 2480 fps | 95.2% |
| Hodgdon H4831 SC | <<locked>> | 94% | 47,369 psi | 73% | 2513 fps | 95.8% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 34,389 psi | 53% | 2257 fps | 99.6% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 52,286 psi | 80% | 2556 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 96% | 38,276 psi | 59% | 2477 fps | 95.9% |
| Hodgdon Superformance | <<locked>> | 80% | 38,667 psi | 59% | 2402 fps | 96.9% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,383 psi | 42% | 1407 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 53,069 psi | 82% | 2520 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 49,226 psi | 76% | 2461 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 80% | 51,387 psi | 79% | 2490 fps | 99.4% |
| IMR 4350 | <<locked>> | 80% | 37,492 psi | 58% | 2290 fps | 96.3% |
| IMR 4451 Enduron | <<locked>> | 80% | 43,192 psi | 66% | 2382 fps | 98.1% |
| IMR 4831 | <<locked>> | 80% | 36,506 psi | 56% | 2306 fps | 99% |
| IMR 4895 | <<locked>> | 80% | 51,576 psi | 79% | 2536 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 90% | 44,396 psi | 68% | 2425 fps | 95.2% |
| IMR 7828 SSC | <<locked>> | 94% | 43,236 psi | 67% | 2500 fps | 95.4% |
| Lovex S060 | <<locked>> | 80% | 53,809 psi | 83% | 2490 fps | 100% |
| Lovex S062 | <<locked>> | 80% | 49,487 psi | 76% | 2457 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 40,828 psi | 63% | 2339 fps | 98.8% |
| Lovex S070 | <<locked>> | 80% | 39,088 psi | 60% | 2323 fps | 97.5% |
| Lovex S071 | <<locked>> | 88% | 30,995 psi | 48% | 2192 fps | 95.7% |
| Norma 201 | <<locked>> | 80% | 53,693 psi | 83% | 2503 fps | 100% |
| Norma 202 | <<locked>> | 80% | 54,244 psi | 83% | 2500 fps | 100% |
| Norma 203B | <<locked>> | 80% | 49,632 psi | 76% | 2500 fps | 100% |
| Norma 204 | <<locked>> | 82% | 39,450 psi | 61% | 2369 fps | 95.5% |
| Norma MRP | <<locked>> | 84% | 33,286 psi | 51% | 2326 fps | 95.2% |
| Norma URP | <<locked>> | 80% | 37,710 psi | 58% | 2343 fps | 99.1% |
| Ramshot Big Game | <<locked>> | 80% | 50,111 psi | 77% | 2526 fps | 100% |
| Ramshot Grand | <<locked>> | 94% | 43,004 psi | 66% | 2507 fps | 95.7% |
| Ramshot Hunter | <<locked>> | 80% | 36,492 psi | 56% | 2333 fps | 97.5% |
| Ramshot Magnum | <<locked>> | 92% | 35,563 psi | 55% | 2343 fps | 95.2% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,949 psi | 43% | 1440 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 47,863 psi | 74% | 2464 fps | 99.3% |
| ReloadSwiss RS 52 | <<locked>> | 80% | 54,708 psi | 84% | 2625 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 44,382 psi | 68% | 2510 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 37,492 psi | 58% | 2362 fps | 98.9% |
| ReloadSwiss RS 70 | 46.4 gr | 80% | 36,448 psi | 56% | 2372 fps | 98.5% |
| ReloadSwiss RS 76 | <<locked>> | 94% | 35,302 psi | 54% | 2405 fps | 95.8% |
| Rottweil R 902 | <<locked>> | 80% | 51,256 psi | 79% | 2464 fps | 100% |
| Rottweil R 903 | <<locked>> | 80% | 44,933 psi | 69% | 2418 fps | 100% |
| Rottweil R 904 | <<locked>> | 88% | 43,250 psi | 67% | 2411 fps | 95.5% |
| Rottweil R 905 | <<locked>> | 86% | 37,985 psi | 58% | 2362 fps | 95.5% |
| Rottweil R 907 | <<locked>> | 80% | 41,771 psi | 64% | 2352 fps | 97.4% |
| Shooters World Long Rifle | <<locked>> | 80% | 40,828 psi | 63% | 2339 fps | 98.8% |
| Shooters World Precision | <<locked>> | 80% | 49,487 psi | 76% | 2457 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 39,088 psi | 60% | 2323 fps | 97.5% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 46,006 psi | 71% | 2470 fps | 100% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 53,432 psi | 82% | 2536 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 54,534 psi | 84% | 2438 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 46,151 psi | 71% | 2323 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 39,813 psi | 61% | 2287 fps | 97.5% |
| SNPE Vectan Tubal 8000 | <<locked>> | 86% | 37,623 psi | 58% | 2356 fps | 95.4% |
| Somchem S335 | <<locked>> | 80% | 54,186 psi | 83% | 2438 fps | 100% |
| Somchem S355 | <<locked>> | 80% | 45,121 psi | 69% | 2415 fps | 100% |
| Somchem S361 | <<locked>> | 90% | 47,224 psi | 73% | 2454 fps | 95.7% |
| Somchem S365 | <<locked>> | 80% | 34,098 psi | 52% | 2303 fps | 100% |
| Somchem S385 | <<locked>> | 84% | 36,056 psi | 55% | 2297 fps | 95.8% |
| Vihtavuori N133 | <<locked>> | 80% | 55,085 psi | 85% | 2421 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 51,605 psi | 79% | 2428 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 51,677 psi | 80% | 2441 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 43,134 psi | 66% | 2352 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 38,914 psi | 60% | 2336 fps | 99.2% |
| Vihtavuori N165 | <<locked>> | 88% | 35,476 psi | 55% | 2277 fps | 95.1% |
| Vihtavuori N540 | <<locked>> | 80% | 49,835 psi | 77% | 2441 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 38,479 psi | 59% | 2343 fps | 99% |
| Vihtavuori N555 | <<locked>> | 80% | 29,878 psi | 46% | 2211 fps | 97.7% |
| Vihtavuori N560 | <<locked>> | 92% | 44,222 psi | 68% | 2536 fps | 95.3% |
| Vihtavuori N565 | <<locked>> | 98% | 42,960 psi | 66% | 2510 fps | 95.3% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 38,145 psi | 59% | 2313 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 39,827 psi | 61% | 2388 fps | 97.6% |
| Winchester StaBALL HD | <<locked>> | 80% | 23,946 psi | 37% | 2123 fps | 96.8% |
| Winchester StaBALL Match | <<locked>> | 80% | 53,359 psi | 82% | 2543 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 88% | 37,768 psi | 58% | 2329 fps | 95.1% |
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 105 powders for .280 Ackley Improved loaded with the .284 | 180gr | TWENTY-NINE ERTP. Norma MRP delivers the highest muzzle velocity at 2,759 fps; across all powders the maximum-charge window runs from 1,572 fps to 2,759 fps. Accurate 3100 gives the best case fill at 100 %, and 105 of the 105 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 180.0 gr projectile in 0.284" calls for a 1:7.5 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, Accurate High Country rank at the top here: for .280 Ackley Improved with the .284 | 180gr | TWENTY-NINE ERTP 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.