Load Specifications
Load data in caliber .243 Ackley Improved with .243 | 100gr | Speer Boat-Tail bullet and 67 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Norma MRP, Alliant Reloder-26 and Alliant Reloder-16.
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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Max Load - Barrel Length: 24"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2700 | <<locked>> | 84% | 48,704 psi | 88% | 2815 fps | 97% |
| Accurate 3100 | <<locked>> | 98% | 47,630 psi | 86% | 2892 fps | 98.4% |
| Accurate 4064 | <<locked>> | 82% | 49,603 psi | 90% | 2861 fps | 100% |
| Accurate 4350 | <<locked>> | 90% | 49,676 psi | 90% | 2953 fps | 99.7% |
| ADI AR 2208 | <<locked>> | 82% | 47,268 psi | 86% | 2838 fps | 99.6% |
| ADI AR 2209 | <<locked>> | 94% | 47,703 psi | 86% | 2925 fps | 95.8% |
| Alliant Reloder- TS 15.5 | <<locked>> | 82% | 47,718 psi | 86% | 2864 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 90% | 47,819 psi | 87% | 2961 fps | 99.7% |
| Alliant Reloder-17 | <<locked>> | 86% | 48,051 psi | 87% | 2978 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 94% | 47,326 psi | 86% | 2920 fps | 95.9% |
| Alliant Reloder-22 | <<locked>> | 98% | 47,543 psi | 86% | 2971 fps | 96.2% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 47,964 psi | 87% | 2972 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 42,148 psi | 76% | 2883 fps | 98% |
| Alliant Reloder-26 | <<locked>> | 96% | 47,442 psi | 86% | 3042 fps | 99.6% |
| Bofors RP3 | <<locked>> | 82% | 47,979 psi | 87% | 2874 fps | 100% |
| Bofors RP5 | <<locked>> | 98% | 47,543 psi | 86% | 2972 fps | 96.2% |
| Bofors RP7 | <<locked>> | 86% | 47,993 psi | 87% | 2850 fps | 97.1% |
| Hodgdon H380 | <<locked>> | 82% | 48,414 psi | 88% | 2884 fps | 99.3% |
| Hodgdon H414 | <<locked>> | 86% | 49,922 psi | 90% | 2965 fps | 98.1% |
| Hodgdon H4350 | <<locked>> | 88% | 47,529 psi | 86% | 2877 fps | 96.3% |
| Hodgdon Hybrid 100V | <<locked>> | 92% | 47,834 psi | 87% | 2889 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 82% | 49,676 psi | 90% | 2933 fps | 100% |
| Hodgdon Superformance | <<locked>> | 88% | 48,356 psi | 88% | 2971 fps | 97.5% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,057 psi | 67% | 1868 fps | 100% |
| Hodgdon VARGET | <<locked>> | 82% | 49,588 psi | 90% | 2881 fps | 100% |
| IMR 4064 | <<locked>> | 84% | 49,066 psi | 89% | 2864 fps | 99.9% |
| IMR 4166 Enduron | <<locked>> | 84% | 48,530 psi | 88% | 2837 fps | 97.7% |
| IMR 4350 | <<locked>> | 90% | 48,530 psi | 88% | 2881 fps | 97.3% |
| IMR 4451 Enduron | <<locked>> | 86% | 49,371 psi | 89% | 2877 fps | 97.8% |
| IMR 4831 | <<locked>> | 94% | 48,066 psi | 87% | 2907 fps | 99.6% |
| Lovex S062 | <<locked>> | 82% | 49,617 psi | 90% | 2868 fps | 100% |
| Lovex S065 | <<locked>> | 88% | 49,269 psi | 89% | 2878 fps | 98.9% |
| Lovex S070 | <<locked>> | 88% | 47,413 psi | 86% | 2863 fps | 97.7% |
| Lovex S071ᴾ | <<locked>> | 100% | 43,076 psi | 78% | 2790 fps | 97.3% |
| Norma 204 | <<locked>> | 90% | 48,747 psi | 88% | 2925 fps | 96% |
| Norma MRP | <<locked>> | 96% | 46,876 psi | 85% | 2993 fps | 97.5% |
| Norma URP | <<locked>> | 90% | 49,023 psi | 89% | 2942 fps | 99.6% |
| Ramshot Hunter | <<locked>> | 90% | 47,805 psi | 87% | 2933 fps | 98.4% |
| Ramshot Magnum | <<locked>> | 98% | 46,151 psi | 84% | 2917 fps | 96.4% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,695 psi | 68% | 1912 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 82% | 48,515 psi | 88% | 2867 fps | 98.3% |
| ReloadSwiss RS 60 | <<locked>> | 84% | 47,921 psi | 87% | 2980 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 90% | 49,574 psi | 90% | 2973 fps | 99.6% |
| ReloadSwiss RS 70 | <<locked>> | 90% | 48,240 psi | 87% | 2992 fps | 99.3% |
| Rottweil R 903 | <<locked>> | 84% | 48,182 psi | 87% | 2873 fps | 100% |
| Rottweil R 905 | <<locked>> | 96% | 49,632 psi | 90% | 2963 fps | 96.7% |
| Rottweil R 907 | <<locked>> | 86% | 47,993 psi | 87% | 2850 fps | 97.1% |
| Shooters World Long Rifle | <<locked>> | 88% | 49,269 psi | 89% | 2878 fps | 98.9% |
| Shooters World Precision | <<locked>> | 82% | 49,617 psi | 90% | 2868 fps | 100% |
| Shooters World SW4350 | <<locked>> | 88% | 47,413 psi | 86% | 2864 fps | 97.7% |
| SNPE Vectan SP 11 | <<locked>> | 84% | 49,240 psi | 89% | 2925 fps | 99.9% |
| SNPE Vectan Tubal 5000 | <<locked>> | 84% | 49,574 psi | 90% | 2772 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 88% | 48,950 psi | 89% | 2826 fps | 97.8% |
| SNPE Vectan Tubal 8000 | <<locked>> | 96% | 49,168 psi | 89% | 2959 fps | 96.6% |
| Somchem S355 | <<locked>> | 84% | 48,182 psi | 87% | 2867 fps | 100% |
| Somchem S365 | <<locked>> | 92% | 47,674 psi | 86% | 2945 fps | 100% |
| Somchem S385 | <<locked>> | 94% | 46,876 psi | 85% | 2879 fps | 96.9% |
| Unknown powder | <<locked>> | 88% | 49,487 psi | 90% | 2944 fps | 99.3% |
| Vihtavuori N150 | <<locked>> | 90% | 49,806 psi | 90% | 2859 fps | 100% |
| Vihtavuori N160 | <<locked>> | 86% | 46,586 psi | 84% | 2857 fps | 99.3% |
| Vihtavuori N165ᴾ | <<locked>> | 100% | 47,529 psi | 86% | 2877 fps | 96.6% |
| Vihtavuori N550 | <<locked>> | 86% | 47,311 psi | 86% | 2907 fps | 99.3% |
| Vihtavuori N555 | <<locked>> | 96% | 46,978 psi | 85% | 2941 fps | 99.7% |
| Winchester 6.5 StaBALL | <<locked>> | 88% | 47,195 psi | 85% | 2851 fps | 100% |
| Winchester 760 | <<locked>> | 86% | 49,922 psi | 90% | 2965 fps | 98.1% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 43,613 psi | 79% | 3019 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 94% | 48,109 psi | 87% | 2894 fps | 96% |
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% | 42,482 psi | 77% | 2697 fps | 95.5% |
| Accurate 3100 | <<locked>> | 90% | 36,187 psi | 65% | 2658 fps | 95.4% |
| Accurate 4064 | <<locked>> | 80% | 46,862 psi | 85% | 2815 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 35,143 psi | 64% | 2651 fps | 96.9% |
| ADI AR 2208 | <<locked>> | 80% | 44,396 psi | 80% | 2783 fps | 99.3% |
| ADI AR 2209 | <<locked>> | 92% | 44,759 psi | 81% | 2866 fps | 95% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 44,440 psi | 80% | 2805 fps | 99.9% |
| Alliant Reloder-16 | 35.8 gr | 80% | 34,708 psi | 63% | 2666 fps | 97% |
| Alliant Reloder-17 | <<locked>> | 80% | 38,986 psi | 71% | 2796 fps | 99.4% |
| Alliant Reloder-19 | <<locked>> | 92% | 44,425 psi | 80% | 2861 fps | 95.1% |
| Alliant Reloder-22 | <<locked>> | 96% | 44,570 psi | 81% | 2910 fps | 95.3% |
| Alliant Reloder-23 | <<locked>> | 82% | 26,905 psi | 49% | 2457 fps | 95% |
| Alliant Reloder-25 | <<locked>> | 94% | 34,563 psi | 63% | 2695 fps | 95.2% |
| Alliant Reloder-26 | 42.5 gr | 86% | 33,170 psi | 60% | 2703 fps | 95.6% |
| Bofors RP3 | <<locked>> | 80% | 44,657 psi | 81% | 2814 fps | 100% |
| Bofors RP5 | <<locked>> | 96% | 44,570 psi | 81% | 2910 fps | 95.3% |
| Bofors RP7 | <<locked>> | 82% | 42,308 psi | 77% | 2737 fps | 95.6% |
| Hodgdon H380 | <<locked>> | 80% | 45,136 psi | 82% | 2823 fps | 98.8% |
| Hodgdon H414 | <<locked>> | 80% | 40,625 psi | 74% | 2780 fps | 95.8% |
| Hodgdon H4350 | <<locked>> | 86% | 44,614 psi | 81% | 2822 fps | 95.5% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 32,271 psi | 58% | 2562 fps | 97.7% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 46,282 psi | 84% | 2874 fps | 100% |
| Hodgdon Superformance | <<locked>> | 84% | 41,974 psi | 76% | 2839 fps | 95.8% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,064 psi | 49% | 1670 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 46,905 psi | 85% | 2831 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 43,482 psi | 79% | 2759 fps | 99.4% |
| IMR 4166 Enduron | <<locked>> | 80% | 42,859 psi | 78% | 2724 fps | 96.4% |
| IMR 4350 | <<locked>> | 84% | 40,277 psi | 73% | 2713 fps | 95% |
| IMR 4451 Enduron | <<locked>> | 80% | 41,017 psi | 74% | 2710 fps | 95.7% |
| IMR 4831 | <<locked>> | 80% | 30,879 psi | 56% | 2525 fps | 95.3% |
| Lovex S062 | <<locked>> | 80% | 46,905 psi | 85% | 2820 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 38,696 psi | 70% | 2663 fps | 96.6% |
| Lovex S070 | <<locked>> | 82% | 39,334 psi | 71% | 2695 fps | 95.6% |
| Lovex S071 | <<locked>> | 96% | 37,260 psi | 67% | 2682 fps | 95.8% |
| Norma 204 | <<locked>> | 88% | 45,368 psi | 82% | 2859 fps | 95.1% |
| Norma MRP | 44.1 gr | 92% | 40,930 psi | 74% | 2863 fps | 95.7% |
| Norma URP | <<locked>> | 80% | 35,085 psi | 63% | 2648 fps | 96.7% |
| Ramshot Hunter | <<locked>> | 82% | 36,564 psi | 66% | 2693 fps | 95.4% |
| Ramshot Magnum | <<locked>> | 96% | 42,786 psi | 77% | 2848 fps | 95.4% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,412 psi | 50% | 1707 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 45,266 psi | 82% | 2806 fps | 97.6% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 41,423 psi | 75% | 2857 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 34,940 psi | 63% | 2669 fps | 96.5% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 34,156 psi | 62% | 2667 fps | 95.5% |
| Rottweil R 903 | <<locked>> | 80% | 42,003 psi | 76% | 2758 fps | 99.7% |
| Rottweil R 905 | <<locked>> | 94% | 46,441 psi | 84% | 2903 fps | 95.9% |
| Rottweil R 907 | <<locked>> | 82% | 42,308 psi | 77% | 2737 fps | 95.6% |
| Shooters World Long Rifle | <<locked>> | 80% | 38,696 psi | 70% | 2663 fps | 96.6% |
| Shooters World Precision | <<locked>> | 80% | 46,905 psi | 85% | 2820 fps | 100% |
| Shooters World SW4350 | <<locked>> | 82% | 39,334 psi | 71% | 2697 fps | 95.6% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 43,091 psi | 78% | 2811 fps | 99.5% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 43,859 psi | 79% | 2680 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 82% | 40,161 psi | 73% | 2654 fps | 95.7% |
| SNPE Vectan Tubal 8000 | <<locked>> | 94% | 46,035 psi | 83% | 2900 fps | 95.8% |
| Somchem S355 | <<locked>> | 80% | 42,757 psi | 77% | 2765 fps | 99.7% |
| Somchem S365 | <<locked>> | 80% | 31,589 psi | 57% | 2601 fps | 98.7% |
| Somchem S385 | <<locked>> | 90% | 41,234 psi | 75% | 2767 fps | 95.3% |
| Unknown powder | <<locked>> | 80% | 37,913 psi | 69% | 2708 fps | 97% |
| Vihtavuori N150 | <<locked>> | 80% | 36,564 psi | 66% | 2606 fps | 99.6% |
| Vihtavuori N160 | <<locked>> | 80% | 38,087 psi | 69% | 2685 fps | 97.6% |
| Vihtavuori N165 | <<locked>> | 96% | 41,742 psi | 76% | 2765 fps | 95% |
| Vihtavuori N550 | <<locked>> | 80% | 38,551 psi | 70% | 2726 fps | 97.6% |
| Vihtavuori N555 | <<locked>> | 82% | 29,428 psi | 53% | 2539 fps | 95.2% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 35,824 psi | 65% | 2622 fps | 98.9% |
| Winchester 760 | <<locked>> | 80% | 40,625 psi | 74% | 2780 fps | 95.8% |
| Winchester StaBALL HD | <<locked>> | 86% | 27,151 psi | 49% | 2545 fps | 95.8% |
| Winchester Supreme 780 | <<locked>> | 92% | 45,034 psi | 81% | 2836 fps | 95.2% |
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 82 powders for .243 Ackley Improved loaded with the .243 | 100gr | Speer Boat-Tail. Alliant Reloder-26 delivers the highest muzzle velocity at 3,042 fps; across all powders the maximum-charge window runs from 1,868 fps to 3,042 fps. Accurate MAGPRO gives the best case fill at 100 %, and 82 of the 82 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (381 MPa), the top charges use 67–90 %, leaving at least 10 % headroom. The 100.0 gr projectile in 0.243" calls for a 1:10.0 twist; slower twists will usually not stabilise this weight. Accurate MAGPRO, Alliant Reloder-23, Alliant Reloder-25 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. Norma MRP, Alliant Reloder-26, Alliant Reloder-16 rank at the top here: for .243 Ackley Improved with the .243 | 100gr | Speer Boat-Tail they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, Accurate MAGPRO, ADI AR 2213, Bofors RP30 burn incompletely and react more sensitively to barrel length and temperature. Always begin at the start load and work up in small increments while checking case and primer for pressure signs.