Load Specifications
Load data in caliber .280 Ackley Improved with .284 | 132gr | Peregrine VLR-4 bullet and 98 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 2015 | <<locked>> | 84% | 57,435 psi | 88% | 2927 fps | 100% |
| Accurate 2495 | <<locked>> | 88% | 56,507 psi | 87% | 2953 fps | 100% |
| Accurate 2520 | <<locked>> | 84% | 58,378 psi | 90% | 3025 fps | 100% |
| Accurate 2700 | <<locked>> | 88% | 55,666 psi | 86% | 2959 fps | 97.3% |
| Accurate 3100ᴾ | <<locked>> | 100% | 43,830 psi | 67% | 2844 fps | 96.6% |
| Accurate 4064 | <<locked>> | 90% | 56,405 psi | 87% | 2999 fps | 100% |
| Accurate 4350 | <<locked>> | 98% | 57,305 psi | 88% | 3100 fps | 99.8% |
| ADI AR 2206H | <<locked>> | 86% | 56,855 psi | 87% | 3038 fps | 100% |
| ADI AR 2208 | <<locked>> | 92% | 58,131 psi | 89% | 3041 fps | 100% |
| ADI Benchmark 8208 | <<locked>> | 84% | 55,782 psi | 86% | 2986 fps | 100% |
| Alliant AR-Comp | <<locked>> | 84% | 57,130 psi | 88% | 2959 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 88% | 57,058 psi | 88% | 3169 fps | 100% |
| Alliant Reloder- TS 15.5 | <<locked>> | 92% | 58,291 psi | 90% | 3064 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 88% | 55,201 psi | 85% | 3031 fps | 99.9% |
| Alliant Reloder-16ᴾ | <<locked>> | 100% | 58,175 psi | 89% | 3159 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 94% | 55,869 psi | 86% | 3136 fps | 100% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 41,684 psi | 64% | 2877 fps | 99.3% |
| Alliant Reloder-26ᴾ | <<locked>> | 100% | 47,181 psi | 73% | 3054 fps | 98.8% |
| Baschieri & Pellagri 107 | <<locked>> | 86% | 56,956 psi | 88% | 3058 fps | 99.8% |
| Bofors RP3 | <<locked>> | 90% | 55,347 psi | 85% | 3025 fps | 100% |
| Bofors RP7 | <<locked>> | 96% | 58,813 psi | 90% | 3051 fps | 98% |
| Hodgdon Benchmark | <<locked>> | 84% | 57,188 psi | 88% | 2966 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 84% | 55,405 psi | 85% | 3018 fps | 100% |
| Hodgdon CFE223 | <<locked>> | 82% | 57,609 psi | 89% | 3123 fps | 100% |
| Hodgdon H380 | <<locked>> | 90% | 56,318 psi | 87% | 3041 fps | 99.5% |
| Hodgdon H414 | <<locked>> | 96% | 56,347 psi | 87% | 3097 fps | 98.3% |
| Hodgdon H4350 | <<locked>> | 94% | 56,710 psi | 87% | 3058 fps | 97.1% |
| Hodgdon H4895 | <<locked>> | 86% | 57,508 psi | 88% | 3051 fps | 100% |
| Hodgdon Hybrid 100Vᴾ | <<locked>> | 100% | 54,462 psi | 84% | 3022 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 88% | 57,653 psi | 89% | 3087 fps | 100% |
| Hodgdon Superformance | <<locked>> | 96% | 57,014 psi | 88% | 3136 fps | 98.1% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 35,607 psi | 55% | 1867 fps | 100% |
| Hodgdon VARGET | <<locked>> | 88% | 58,769 psi | 90% | 3051 fps | 100% |
| IMR 3031 | <<locked>> | 86% | 57,856 psi | 89% | 3031 fps | 100% |
| IMR 4064 | <<locked>> | 90% | 57,450 psi | 88% | 3025 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 88% | 57,246 psi | 88% | 3002 fps | 98.3% |
| IMR 4350 | <<locked>> | 98% | 56,028 psi | 86% | 3028 fps | 97.7% |
| IMR 4451 Enduron | <<locked>> | 94% | 57,246 psi | 88% | 3031 fps | 98.2% |
| IMR 4831ᴾ | <<locked>> | 100% | 57,682 psi | 89% | 3087 fps | 99.9% |
| IMR 4895 | <<locked>> | 88% | 56,637 psi | 87% | 3064 fps | 100% |
| IMR 8208 XBR | <<locked>> | 84% | 55,782 psi | 86% | 2986 fps | 100% |
| Lovex D073.6 | <<locked>> | 86% | 57,000 psi | 88% | 3015 fps | 100% |
| Lovex S060 | <<locked>> | 86% | 56,159 psi | 86% | 2966 fps | 100% |
| Lovex S062 | <<locked>> | 90% | 57,188 psi | 88% | 3015 fps | 100% |
| Lovex S065 | <<locked>> | 96% | 56,536 psi | 87% | 3018 fps | 99.1% |
| Lovex S070 | <<locked>> | 98% | 57,957 psi | 89% | 3061 fps | 98.6% |
| Norma 201 | <<locked>> | 86% | 55,419 psi | 85% | 2979 fps | 100% |
| Norma 202 | <<locked>> | 86% | 56,275 psi | 87% | 2982 fps | 100% |
| Norma 203B | <<locked>> | 90% | 58,015 psi | 89% | 3071 fps | 100% |
| Norma 204 | <<locked>> | 98% | 56,782 psi | 87% | 3077 fps | 96.6% |
| Norma MRPᴾ | <<locked>> | 100% | 46,876 psi | 72% | 3009 fps | 96.2% |
| Norma URP | <<locked>> | 98% | 56,260 psi | 87% | 3087 fps | 99.7% |
| Ramshot Big Game | <<locked>> | 88% | 55,085 psi | 85% | 3041 fps | 100% |
| Ramshot Hunterᴾ | <<locked>> | 100% | 58,711 psi | 90% | 3140 fps | 99.2% |
| Ramshot TAC | <<locked>> | 84% | 55,956 psi | 86% | 3005 fps | 99.2% |
| Ramshot Wild Boar | <<locked>> | 84% | 56,043 psi | 86% | 3028 fps | 100% |
| Ramshot X-Terminator | <<locked>> | 82% | 56,492 psi | 87% | 2986 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 36,114 psi | 56% | 1909 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 90% | 56,623 psi | 87% | 3022 fps | 98.7% |
| ReloadSwiss RS 52 | <<locked>> | 86% | 55,970 psi | 86% | 3104 fps | 99.9% |
| ReloadSwiss RS 60 | <<locked>> | 92% | 55,709 psi | 86% | 3140 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 98% | 57,159 psi | 88% | 3123 fps | 99.7% |
| ReloadSwiss RS 70 | <<locked>> | 98% | 56,449 psi | 87% | 3156 fps | 99.6% |
| Rottweil R 901 | <<locked>> | 84% | 56,115 psi | 86% | 2959 fps | 100% |
| Rottweil R 902 | <<locked>> | 88% | 55,927 psi | 86% | 2979 fps | 100% |
| Rottweil R 903 | <<locked>> | 92% | 55,187 psi | 85% | 3015 fps | 100% |
| Rottweil R 907 | <<locked>> | 96% | 58,813 psi | 90% | 3051 fps | 98% |
| Shooters World Long Rifle | <<locked>> | 96% | 56,536 psi | 87% | 3018 fps | 99.1% |
| Shooters World Match Rifle | <<locked>> | 86% | 57,000 psi | 88% | 3015 fps | 100% |
| Shooters World Precision | <<locked>> | 90% | 57,188 psi | 88% | 3015 fps | 100% |
| Shooters World SW4350 | <<locked>> | 98% | 57,957 psi | 89% | 3061 fps | 98.6% |
| SNPE Vectan SP 11 | <<locked>> | 92% | 57,305 psi | 88% | 3084 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 86% | 58,624 psi | 90% | 3045 fps | 99.6% |
| SNPE Vectan SP 9 | <<locked>> | 86% | 55,434 psi | 85% | 3009 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 86% | 56,869 psi | 87% | 2917 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 92% | 57,435 psi | 88% | 2913 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 96% | 56,971 psi | 88% | 2972 fps | 98.2% |
| Somchem S321 | <<locked>> | 82% | 56,985 psi | 88% | 3018 fps | 100% |
| Somchem S335 | <<locked>> | 86% | 56,289 psi | 87% | 2913 fps | 100% |
| Somchem S341 | <<locked>> | 86% | 58,073 psi | 89% | 3031 fps | 100% |
| Somchem S355 | <<locked>> | 92% | 55,448 psi | 85% | 3015 fps | 100% |
| Somchem S365ᴾ | <<locked>> | 100% | 54,534 psi | 84% | 3087 fps | 100% |
| Somchem S385ᴾ | <<locked>> | 100% | 50,082 psi | 77% | 2956 fps | 96.4% |
| Vihtavuori N130 | <<locked>> | 82% | 56,347 psi | 87% | 2874 fps | 100% |
| Vihtavuori N133 | <<locked>> | 86% | 57,232 psi | 88% | 2900 fps | 100% |
| Vihtavuori N135 | <<locked>> | 88% | 55,854 psi | 86% | 2940 fps | 100% |
| Vihtavuori N140 | <<locked>> | 88% | 56,710 psi | 87% | 2959 fps | 100% |
| Vihtavuori N150 | <<locked>> | 94% | 57,130 psi | 88% | 2992 fps | 100% |
| Vihtavuori N160 | <<locked>> | 98% | 58,769 psi | 90% | 3084 fps | 99.8% |
| Vihtavuori N530 | <<locked>> | 84% | 56,434 psi | 87% | 2989 fps | 100% |
| Vihtavuori N540 | <<locked>> | 90% | 58,682 psi | 90% | 3005 fps | 100% |
| Vihtavuori N550 | <<locked>> | 98% | 57,769 psi | 89% | 3087 fps | 99.7% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 46,093 psi | 71% | 2956 fps | 99.1% |
| Winchester 6.5 StaBALL | <<locked>> | 96% | 55,317 psi | 85% | 3005 fps | 100% |
| Winchester 748 | <<locked>> | 84% | 56,710 psi | 87% | 3038 fps | 100% |
| Winchester 760 | <<locked>> | 96% | 56,666 psi | 87% | 3100 fps | 98.3% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 37,173 psi | 57% | 2881 fps | 99.3% |
| Winchester StaBALL Match | <<locked>> | 86% | 55,405 psi | 85% | 3018 fps | 100% |
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 2015 | <<locked>> | 80% | 50,604 psi | 78% | 2828 fps | 100% |
| Accurate 2495 | <<locked>> | 80% | 43,149 psi | 66% | 2746 fps | 100% |
| Accurate 2520 | <<locked>> | 80% | 50,879 psi | 78% | 2913 fps | 100% |
| Accurate 2700 | <<locked>> | 84% | 48,689 psi | 75% | 2841 fps | 95.8% |
| Accurate 3100 | <<locked>> | 98% | 40,828 psi | 63% | 2785 fps | 95.8% |
| Accurate 4064 | <<locked>> | 80% | 40,872 psi | 63% | 2743 fps | 100% |
| Accurate 4350 | <<locked>> | 84% | 34,737 psi | 53% | 2671 fps | 95.6% |
| ADI AR 2206H | <<locked>> | 80% | 46,876 psi | 72% | 2871 fps | 99.4% |
| ADI AR 2208 | <<locked>> | 80% | 39,813 psi | 61% | 2710 fps | 97.7% |
| ADI Benchmark 8208 | <<locked>> | 80% | 49,037 psi | 75% | 2877 fps | 100% |
| Alliant AR-Comp | <<locked>> | 80% | 49,705 psi | 76% | 2858 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 42,931 psi | 66% | 2904 fps | 98.4% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 39,537 psi | 61% | 2730 fps | 98.9% |
| Alliant Reloder-15 | <<locked>> | 80% | 42,496 psi | 65% | 2799 fps | 98.5% |
| Alliant Reloder-16 | <<locked>> | 84% | 34,867 psi | 54% | 2687 fps | 95.7% |
| Alliant Reloder-17 | 50.3 gr | 80% | 34,345 psi | 53% | 2700 fps | 97.4% |
| Alliant Reloder-23 | <<locked>> | 90% | 30,139 psi | 46% | 2575 fps | 95.3% |
| Alliant Reloder-26 | <<locked>> | 94% | 37,753 psi | 58% | 2841 fps | 96.1% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 46,557 psi | 72% | 2877 fps | 98.8% |
| Bofors RP3 | <<locked>> | 80% | 39,204 psi | 60% | 2733 fps | 99% |
| Bofors RP7 | <<locked>> | 88% | 45,614 psi | 70% | 2822 fps | 95.3% |
| Hodgdon Benchmark | <<locked>> | 80% | 50,691 psi | 78% | 2867 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 80% | 48,153 psi | 74% | 2900 fps | 100% |
| Hodgdon CFE223 | <<locked>> | 80% | 53,635 psi | 83% | 3061 fps | 99.8% |
| Hodgdon H380 | <<locked>> | 80% | 40,205 psi | 62% | 2743 fps | 96.8% |
| Hodgdon H414 | 54.1 gr | 88% | 42,946 psi | 66% | 2851 fps | 95.3% |
| Hodgdon H4350 | <<locked>> | 90% | 49,821 psi | 77% | 2940 fps | 95.6% |
| Hodgdon H4895 | <<locked>> | 80% | 47,355 psi | 73% | 2884 fps | 99.7% |
| Hodgdon Hybrid 100V | <<locked>> | 82% | 29,921 psi | 46% | 2516 fps | 95.5% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 43,526 psi | 67% | 2851 fps | 99.6% |
| Hodgdon Superformance | <<locked>> | 90% | 45,890 psi | 71% | 2933 fps | 95.6% |
| Hodgdon TrailBoss | <<locked>> | 80% | 26,339 psi | 41% | 1663 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 45,600 psi | 70% | 2835 fps | 99.6% |
| IMR 3031 | <<locked>> | 80% | 47,384 psi | 73% | 2874 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 41,814 psi | 64% | 2746 fps | 98.4% |
| IMR 4166 Enduron | <<locked>> | 80% | 44,353 psi | 68% | 2772 fps | 95.6% |
| IMR 4350 | <<locked>> | 92% | 46,195 psi | 71% | 2854 fps | 95.5% |
| IMR 4451 Enduron | <<locked>> | 86% | 44,643 psi | 69% | 2805 fps | 95.5% |
| IMR 4831 | <<locked>> | 84% | 33,750 psi | 52% | 2628 fps | 95.3% |
| IMR 4895 | <<locked>> | 80% | 43,555 psi | 67% | 2831 fps | 99.1% |
| IMR 8208 XBR | <<locked>> | 80% | 49,037 psi | 75% | 2877 fps | 100% |
| Lovex D073.6 | <<locked>> | 80% | 46,369 psi | 71% | 2848 fps | 100% |
| Lovex S060 | <<locked>> | 80% | 46,659 psi | 72% | 2802 fps | 99.5% |
| Lovex S062 | <<locked>> | 80% | 41,684 psi | 64% | 2746 fps | 99.5% |
| Lovex S065 | <<locked>> | 84% | 38,812 psi | 60% | 2684 fps | 95.4% |
| Lovex S070 | <<locked>> | 88% | 41,916 psi | 64% | 2772 fps | 95.2% |
| Norma 201 | <<locked>> | 80% | 45,832 psi | 71% | 2818 fps | 99.8% |
| Norma 202 | <<locked>> | 80% | 46,195 psi | 71% | 2822 fps | 100% |
| Norma 203B | <<locked>> | 80% | 41,843 psi | 64% | 2785 fps | 98.8% |
| Norma 204 | <<locked>> | 96% | 53,098 psi | 82% | 3018 fps | 95.8% |
| Norma MRP | <<locked>> | 98% | 43,584 psi | 67% | 2936 fps | 95.2% |
| Norma URP | <<locked>> | 84% | 35,172 psi | 54% | 2677 fps | 95.6% |
| Ramshot Big Game | <<locked>> | 80% | 41,669 psi | 64% | 2802 fps | 98.6% |
| Ramshot Hunter | <<locked>> | 88% | 39,146 psi | 60% | 2772 fps | 95% |
| Ramshot TAC | <<locked>> | 80% | 49,182 psi | 76% | 2890 fps | 98.2% |
| Ramshot Wild Boar | <<locked>> | 80% | 48,791 psi | 75% | 2910 fps | 99.6% |
| Ramshot X-Terminator | <<locked>> | 80% | 52,823 psi | 81% | 2930 fps | 99.9% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 26,861 psi | 41% | 1709 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 40,393 psi | 62% | 2723 fps | 95.1% |
| ReloadSwiss RS 52 | <<locked>> | 80% | 45,324 psi | 70% | 2917 fps | 98.9% |
| ReloadSwiss RS 60 | 50.3 gr | 80% | 36,622 psi | 56% | 2772 fps | 99.7% |
| ReloadSwiss RS 62 | <<locked>> | 84% | 34,606 psi | 53% | 2687 fps | 95.1% |
| ReloadSwiss RS 70 | <<locked>> | 86% | 37,144 psi | 57% | 2759 fps | 95.2% |
| Rottweil R 901 | <<locked>> | 80% | 49,588 psi | 76% | 2858 fps | 100% |
| Rottweil R 902 | <<locked>> | 80% | 43,526 psi | 67% | 2769 fps | 99.7% |
| Rottweil R 903 | <<locked>> | 80% | 36,912 psi | 57% | 2677 fps | 98.3% |
| Rottweil R 907 | <<locked>> | 88% | 45,614 psi | 70% | 2822 fps | 95.3% |
| Shooters World Long Rifle | <<locked>> | 84% | 38,812 psi | 60% | 2684 fps | 95.4% |
| Shooters World Match Rifle | <<locked>> | 80% | 46,369 psi | 71% | 2848 fps | 100% |
| Shooters World Precision | <<locked>> | 80% | 41,684 psi | 64% | 2746 fps | 99.5% |
| Shooters World SW4350 | <<locked>> | 88% | 41,916 psi | 64% | 2772 fps | 95.2% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 38,159 psi | 59% | 2730 fps | 97.9% |
| SNPE Vectan SP 7 | <<locked>> | 80% | 47,398 psi | 73% | 2861 fps | 98.3% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 45,556 psi | 70% | 2838 fps | 99.3% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 47,065 psi | 72% | 2766 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 39,291 psi | 60% | 2625 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 88% | 43,671 psi | 67% | 2743 fps | 95.5% |
| Somchem S321 | <<locked>> | 80% | 53,461 psi | 82% | 2963 fps | 100% |
| Somchem S335 | <<locked>> | 80% | 46,760 psi | 72% | 2769 fps | 100% |
| Somchem S341 | <<locked>> | 80% | 47,355 psi | 73% | 2858 fps | 99.5% |
| Somchem S355 | <<locked>> | 80% | 37,724 psi | 58% | 2684 fps | 98.3% |
| Somchem S365 | <<locked>> | 80% | 27,398 psi | 42% | 2500 fps | 95.8% |
| Somchem S385 | <<locked>> | 98% | 46,833 psi | 72% | 2897 fps | 95.6% |
| Vihtavuori N130 | <<locked>> | 80% | 53,084 psi | 82% | 2828 fps | 100% |
| Vihtavuori N133 | <<locked>> | 80% | 47,529 psi | 73% | 2759 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 43,250 psi | 67% | 2746 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 43,903 psi | 68% | 2756 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 35,911 psi | 55% | 2615 fps | 98.9% |
| Vihtavuori N160 | <<locked>> | 82% | 34,243 psi | 53% | 2618 fps | 95.1% |
| Vihtavuori N530 | <<locked>> | 80% | 49,182 psi | 76% | 2874 fps | 100% |
| Vihtavuori N540 | <<locked>> | 80% | 42,380 psi | 65% | 2746 fps | 100% |
| Vihtavuori N550 | <<locked>> | 84% | 36,100 psi | 56% | 2677 fps | 95.6% |
| Vihtavuori N555 | <<locked>> | 90% | 32,648 psi | 50% | 2657 fps | 95.5% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 31,836 psi | 49% | 2536 fps | 96.6% |
| Winchester 748 | <<locked>> | 80% | 49,458 psi | 76% | 2927 fps | 100% |
| Winchester 760 | <<locked>> | 88% | 42,946 psi | 66% | 2851 fps | 95.3% |
| Winchester StaBALL HD | <<locked>> | 94% | 30,356 psi | 47% | 2664 fps | 96.2% |
| Winchester StaBALL Match | <<locked>> | 80% | 45,078 psi | 69% | 2841 fps | 99.6% |
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 98 powders for .280 Ackley Improved loaded with the .284 | 132gr | Peregrine VLR-4. Alliant Power Pro 2000-MR delivers the highest muzzle velocity at 3,169 fps; across all powders the maximum-charge window runs from 1,867 fps to 3,169 fps. Accurate 3100 gives the best case fill at 100 %, and 98 of the 98 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (448 MPa), the top charges use 55–90 %, leaving at least 10 % headroom. The 132.0 gr projectile in 0.284" calls for a 1:9.5 twist; slower twists will usually not stabilise this weight. Accurate 3100, Alliant Reloder-16, Alliant Reloder-23 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 | 132gr | Peregrine VLR-4 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.