Load Specifications
Load data in caliber .243 Ackley Improved with .243 | 100gr | Sierra SBT GameKing bullet and 59 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Alliant Reloder-26, Norma MRP and ReloadSwiss RS 70.
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 3100 | <<locked>> | 96% | 47,311 psi | 86% | 2897 fps | 98.6% |
| Accurate 4350 | <<locked>> | 88% | 49,371 psi | 89% | 2956 fps | 99.8% |
| ADI AR 2208 | <<locked>> | 82% | 49,052 psi | 89% | 2884 fps | 99.9% |
| ADI AR 2209 | <<locked>> | 92% | 47,297 psi | 86% | 2933 fps | 96.2% |
| Alliant Power Pro Varmint | <<locked>> | 92% | 47,282 psi | 86% | 2930 fps | 96.2% |
| Alliant Power Pro Varmint | <<locked>> | 92% | 47,282 psi | 86% | 2930 fps | 96.2% |
| Alliant Reloder- TS 15.5 | <<locked>> | 82% | 49,617 psi | 90% | 2910 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 88% | 47,210 psi | 85% | 2963 fps | 99.8% |
| Alliant Reloder-17 | <<locked>> | 84% | 47,427 psi | 86% | 2976 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 94% | 49,966 psi | 90% | 2982 fps | 96.9% |
| Alliant Reloder-22 | <<locked>> | 96% | 47,094 psi | 85% | 2976 fps | 96.4% |
| Alliant Reloder-23 | <<locked>> | 98% | 47,863 psi | 87% | 2982 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 44,411 psi | 80% | 2949 fps | 98.9% |
| Alliant Reloder-26 | <<locked>> | 94% | 47,311 psi | 86% | 3048 fps | 99.7% |
| Bofors RP15ᴾ | <<locked>> | 100% | 49,400 psi | 89% | 3018 fps | 96.9% |
| Bofors RP5 | <<locked>> | 96% | 47,094 psi | 85% | 2976 fps | 96.4% |
| Bofors RP7 | <<locked>> | 86% | 49,879 psi | 90% | 2900 fps | 97.8% |
| Hodgdon H414 | <<locked>> | 86% | 48,138 psi | 87% | 2946 fps | 98% |
| Hodgdon H4350 | <<locked>> | 84% | 48,124 psi | 87% | 2904 fps | 96.8% |
| Hodgdon Hybrid 100V | <<locked>> | 90% | 47,181 psi | 85% | 2890 fps | 100% |
| Hodgdon Superformance | <<locked>> | 86% | 47,514 psi | 86% | 2966 fps | 97.6% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,318 psi | 66% | 1890 fps | 100% |
| IMR 4350 | <<locked>> | 88% | 47,659 psi | 86% | 2881 fps | 97.4% |
| IMR 4451 Enduron | <<locked>> | 84% | 48,588 psi | 88% | 2881 fps | 97.9% |
| IMR 4831 | <<locked>> | 88% | 46,775 psi | 85% | 2894 fps | 99.6% |
| Lovex S065 | <<locked>> | 86% | 48,602 psi | 88% | 2881 fps | 99% |
| Lovex S070 | <<locked>> | 88% | 49,647 psi | 90% | 2917 fps | 98.4% |
| Lovex S071ᴾ | <<locked>> | 100% | 44,991 psi | 81% | 2854 fps | 98.2% |
| Norma 204 | <<locked>> | 88% | 48,066 psi | 87% | 2927 fps | 96.2% |
| Norma MRP | <<locked>> | 96% | 49,835 psi | 90% | 3061 fps | 98.4% |
| Norma URP | <<locked>> | 88% | 48,341 psi | 87% | 2940 fps | 99.6% |
| Ramshot Hunter | <<locked>> | 88% | 47,326 psi | 86% | 2936 fps | 98.6% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 47,123 psi | 85% | 2956 fps | 97.1% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 36,941 psi | 67% | 1932 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 82% | 47,036 psi | 85% | 2972 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 88% | 49,095 psi | 89% | 2976 fps | 99.6% |
| ReloadSwiss RS 70 | <<locked>> | 88% | 47,514 psi | 86% | 2992 fps | 99.4% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 43,395 psi | 79% | 2966 fps | 97% |
| Rottweil R 903 | <<locked>> | 82% | 47,442 psi | 86% | 2871 fps | 100% |
| Rottweil R 905 | <<locked>> | 94% | 48,921 psi | 89% | 2963 fps | 96.9% |
| Rottweil R 907 | <<locked>> | 86% | 49,879 psi | 90% | 2900 fps | 97.8% |
| Shooters World Long Rifle | <<locked>> | 86% | 48,602 psi | 88% | 2881 fps | 99% |
| Shooters World SW4350 | <<locked>> | 88% | 49,647 psi | 90% | 2917 fps | 98.4% |
| SNPE Vectan SP 11 | <<locked>> | 82% | 48,646 psi | 88% | 2927 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 82% | 48,385 psi | 88% | 2766 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 86% | 47,993 psi | 87% | 2825 fps | 98% |
| SNPE Vectan Tubal 8000 | <<locked>> | 94% | 48,472 psi | 88% | 2956 fps | 96.7% |
| Somchem S355 | <<locked>> | 82% | 47,456 psi | 86% | 2864 fps | 100% |
| Somchem S365 | <<locked>> | 90% | 47,471 psi | 86% | 2949 fps | 100% |
| Somchem S385 | <<locked>> | 94% | 49,850 psi | 90% | 2946 fps | 97.8% |
| Vihtavuori N150 | <<locked>> | 84% | 48,457 psi | 88% | 2844 fps | 100% |
| Vihtavuori N160 | <<locked>> | 86% | 47,007 psi | 85% | 2881 fps | 99.5% |
| Vihtavuori N165 | <<locked>> | 98% | 48,979 psi | 89% | 2917 fps | 97.3% |
| Vihtavuori N550 | <<locked>> | 88% | 49,501 psi | 90% | 2940 fps | 99.6% |
| Vihtavuori N555 | <<locked>> | 96% | 50,009 psi | 90% | 3002 fps | 100% |
| Winchester 6.5 StaBALL | <<locked>> | 88% | 49,690 psi | 90% | 2904 fps | 100% |
| Winchester 760 | <<locked>> | 86% | 48,138 psi | 87% | 2946 fps | 98% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 46,079 psi | 83% | 3091 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 96% | 49,559 psi | 90% | 2933 fps | 96.7% |
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 3100 | <<locked>> | 88% | 36,114 psi | 65% | 2664 fps | 95.7% |
| Accurate 4350 | <<locked>> | 80% | 37,289 psi | 67% | 2710 fps | 97.8% |
| ADI AR 2208 | <<locked>> | 80% | 46,238 psi | 84% | 2831 fps | 99.7% |
| ADI AR 2209 | <<locked>> | 90% | 44,193 psi | 80% | 2871 fps | 95.2% |
| Alliant Power Pro Varmint | <<locked>> | 90% | 44,193 psi | 80% | 2867 fps | 95.3% |
| Alliant Power Pro Varmint | <<locked>> | 90% | 44,193 psi | 80% | 2867 fps | 95.3% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 46,717 psi | 85% | 2858 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 80% | 36,332 psi | 66% | 2720 fps | 97.9% |
| Alliant Reloder-17 | <<locked>> | 80% | 41,249 psi | 75% | 2854 fps | 99.8% |
| Alliant Reloder-19 | <<locked>> | 90% | 43,685 psi | 79% | 2861 fps | 95.3% |
| Alliant Reloder-22 | <<locked>> | 94% | 44,295 psi | 80% | 2917 fps | 95.6% |
| Alliant Reloder-23 | <<locked>> | 80% | 26,716 psi | 48% | 2461 fps | 95.2% |
| Alliant Reloder-25 | <<locked>> | 92% | 34,490 psi | 62% | 2707 fps | 95.6% |
| Alliant Reloder-26 | 43.5 gr | 84% | 32,822 psi | 59% | 2703 fps | 95.8% |
| Bofors RP15 | <<locked>> | 96% | 43,352 psi | 78% | 2894 fps | 95.1% |
| Bofors RP5 | <<locked>> | 94% | 44,295 psi | 80% | 2917 fps | 95.6% |
| Bofors RP7 | <<locked>> | 80% | 41,365 psi | 75% | 2730 fps | 95.7% |
| Hodgdon H414 | <<locked>> | 80% | 39,218 psi | 71% | 2756 fps | 95.7% |
| Hodgdon H4350 | <<locked>> | 80% | 42,134 psi | 76% | 2782 fps | 95.1% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 34,011 psi | 62% | 2615 fps | 98.5% |
| Hodgdon Superformance | <<locked>> | 82% | 41,220 psi | 75% | 2835 fps | 95.9% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,238 psi | 49% | 1690 fps | 100% |
| IMR 4350 | <<locked>> | 82% | 39,595 psi | 72% | 2713 fps | 95.1% |
| IMR 4451 Enduron | <<locked>> | 80% | 42,902 psi | 78% | 2766 fps | 96.6% |
| IMR 4831 | <<locked>> | 80% | 35,998 psi | 65% | 2664 fps | 97.5% |
| Lovex S065 | <<locked>> | 80% | 40,379 psi | 73% | 2713 fps | 97.4% |
| Lovex S070 | <<locked>> | 80% | 38,566 psi | 70% | 2690 fps | 95.7% |
| Lovex S071 | <<locked>> | 92% | 34,867 psi | 63% | 2635 fps | 95.3% |
| Norma 204 | <<locked>> | 86% | 44,875 psi | 81% | 2864 fps | 95.4% |
| Norma MRP | 45.2 gr | 90% | 40,466 psi | 73% | 2864 fps | 95.9% |
| Norma URP | <<locked>> | 80% | 37,144 psi | 67% | 2707 fps | 97.6% |
| Ramshot Hunter | <<locked>> | 80% | 36,100 psi | 65% | 2690 fps | 95.5% |
| Ramshot Magnum | <<locked>> | 96% | 40,828 psi | 74% | 2822 fps | 95.1% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,586 psi | 50% | 1729 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 43,816 psi | 79% | 2913 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 37,173 psi | 67% | 2730 fps | 97.5% |
| ReloadSwiss RS 70 | 41 gr | 80% | 35,955 psi | 65% | 2730 fps | 96.6% |
| ReloadSwiss RS 76 | <<locked>> | 98% | 40,538 psi | 73% | 2897 fps | 95.9% |
| Rottweil R 903 | <<locked>> | 80% | 44,280 psi | 80% | 2812 fps | 99.9% |
| Rottweil R 905 | <<locked>> | 90% | 42,830 psi | 78% | 2844 fps | 95.2% |
| Rottweil R 907 | <<locked>> | 80% | 41,365 psi | 75% | 2730 fps | 95.7% |
| Shooters World Long Rifle | <<locked>> | 80% | 40,379 psi | 73% | 2713 fps | 97.4% |
| Shooters World SW4350 | <<locked>> | 80% | 38,566 psi | 70% | 2690 fps | 95.7% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 45,498 psi | 82% | 2867 fps | 99.8% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 45,469 psi | 82% | 2720 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 39,465 psi | 71% | 2654 fps | 95.8% |
| SNPE Vectan Tubal 8000 | <<locked>> | 90% | 42,438 psi | 77% | 2835 fps | 95% |
| Somchem S355 | <<locked>> | 80% | 44,643 psi | 81% | 2812 fps | 99.9% |
| Somchem S365 | <<locked>> | 80% | 33,576 psi | 61% | 2661 fps | 99.4% |
| Somchem S385 | <<locked>> | 88% | 40,712 psi | 74% | 2766 fps | 95.5% |
| Vihtavuori N150 | <<locked>> | 80% | 42,612 psi | 77% | 2740 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 38,479 psi | 70% | 2707 fps | 98% |
| Vihtavuori N165 | <<locked>> | 94% | 42,989 psi | 78% | 2805 fps | 95.8% |
| Vihtavuori N550 | <<locked>> | 80% | 38,130 psi | 69% | 2710 fps | 97.7% |
| Vihtavuori N555 | <<locked>> | 80% | 29,428 psi | 53% | 2543 fps | 95.5% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 37,840 psi | 68% | 2680 fps | 99.5% |
| Winchester 760 | <<locked>> | 80% | 39,508 psi | 71% | 2766 fps | 95.8% |
| Winchester StaBALL HD | <<locked>> | 84% | 26,948 psi | 49% | 2552 fps | 96.2% |
| Winchester Supreme 780 | <<locked>> | 92% | 43,004 psi | 78% | 2808 fps | 95% |
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 59 powders for .243 Ackley Improved loaded with the .243 | 100gr | Sierra SBT GameKing. Winchester StaBALL HD delivers the highest muzzle velocity at 3,091 fps; across all powders the maximum-charge window runs from 1,890 fps to 3,091 fps. Alliant Reloder-25 gives the best case fill at 100 %, and 59 of the 59 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (381 MPa), the top charges use 66–90 %, 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. Alliant Reloder-25, Bofors RP15, Hodgdon TrailBoss 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, Norma MRP, ReloadSwiss RS 70 rank at the top here: for .243 Ackley Improved with the .243 | 100gr | Sierra SBT GameKing 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.