Load Specifications
Load data in caliber .243 Ackley Improved with .243 | 90gr | Sierra FMJBT GameKing bullet and 56 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 Norma MRP.
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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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 2700 | <<locked>> | 82% | 49,922 psi | 90% | 2995 fps | 96.6% |
| Accurate 3100 | <<locked>> | 98% | 47,036 psi | 85% | 3022 fps | 97.7% |
| Accurate 4064 | <<locked>> | 82% | 49,023 psi | 89% | 3009 fps | 100% |
| Accurate 4350 | <<locked>> | 90% | 49,124 psi | 89% | 3094 fps | 99.3% |
| ADI AR 2208 | <<locked>> | 84% | 49,690 psi | 90% | 3038 fps | 99.6% |
| Alliant Reloder- TS 15.5 | <<locked>> | 82% | 46,818 psi | 85% | 3002 fps | 99.9% |
| Alliant Reloder-16 | <<locked>> | 90% | 47,224 psi | 85% | 3100 fps | 99.3% |
| Alliant Reloder-17 | <<locked>> | 86% | 47,529 psi | 86% | 3120 fps | 99.9% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 47,224 psi | 85% | 3107 fps | 99.9% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 41,350 psi | 75% | 3002 fps | 97% |
| Alliant Reloder-26 | <<locked>> | 96% | 46,949 psi | 85% | 3176 fps | 99.1% |
| Bofors RP3 | <<locked>> | 82% | 47,166 psi | 85% | 3015 fps | 99.9% |
| Bofors RP7 | <<locked>> | 86% | 47,442 psi | 86% | 2989 fps | 96.2% |
| Hodgdon H380 | <<locked>> | 82% | 47,892 psi | 87% | 3025 fps | 98.7% |
| Hodgdon H414 | <<locked>> | 88% | 48,327 psi | 87% | 3084 fps | 97.1% |
| Hodgdon Hybrid 100V | <<locked>> | 92% | 47,050 psi | 85% | 3025 fps | 99.8% |
| Hodgdon Superformance | <<locked>> | 88% | 47,805 psi | 87% | 3104 fps | 96.6% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,042 psi | 65% | 1988 fps | 100% |
| IMR 4064 | <<locked>> | 82% | 48,965 psi | 89% | 3015 fps | 99.6% |
| IMR 4350 | <<locked>> | 90% | 48,109 psi | 87% | 3018 fps | 96.4% |
| IMR 4451 Enduron | <<locked>> | 86% | 48,776 psi | 88% | 3018 fps | 97% |
| IMR 4831 | <<locked>> | 92% | 49,879 psi | 90% | 3091 fps | 99.4% |
| Lovex S062 | <<locked>> | 82% | 49,153 psi | 89% | 3015 fps | 100% |
| Lovex S065 | <<locked>> | 88% | 48,892 psi | 88% | 3022 fps | 98.3% |
| Lovex S070 | <<locked>> | 90% | 49,777 psi | 90% | 3058 fps | 97.6% |
| Lovex S071ᴾ | <<locked>> | 100% | 41,669 psi | 75% | 2913 fps | 96.4% |
| Norma 203B | <<locked>> | 82% | 49,603 psi | 90% | 3064 fps | 99.8% |
| Norma MRP | <<locked>> | 98% | 49,734 psi | 90% | 3192 fps | 97.4% |
| Norma URP | <<locked>> | 90% | 48,240 psi | 87% | 3077 fps | 99.1% |
| Ramshot Big Game | <<locked>> | 82% | 49,893 psi | 90% | 3084 fps | 99.8% |
| Ramshot Hunter | <<locked>> | 90% | 47,036 psi | 85% | 3068 fps | 97.7% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 36,593 psi | 66% | 2034 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 82% | 47,834 psi | 87% | 3002 fps | 97.5% |
| ReloadSwiss RS 60 | <<locked>> | 84% | 47,224 psi | 85% | 3127 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 90% | 48,907 psi | 89% | 3110 fps | 99.1% |
| ReloadSwiss RS 70 | <<locked>> | 90% | 47,863 psi | 87% | 3133 fps | 98.8% |
| Rottweil R 903 | <<locked>> | 84% | 47,355 psi | 86% | 3012 fps | 99.9% |
| Rottweil R 907 | <<locked>> | 86% | 47,442 psi | 86% | 2989 fps | 96.2% |
| Shooters World Long Rifle | <<locked>> | 88% | 48,892 psi | 88% | 3022 fps | 98.3% |
| Shooters World Precision | <<locked>> | 82% | 49,153 psi | 89% | 3015 fps | 100% |
| Shooters World SW4350 | <<locked>> | 90% | 49,777 psi | 90% | 3058 fps | 97.6% |
| SNPE Vectan SP 11 | <<locked>> | 84% | 48,733 psi | 88% | 3068 fps | 99.7% |
| SNPE Vectan Tubal 5000 | <<locked>> | 84% | 48,849 psi | 88% | 2917 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 88% | 48,356 psi | 88% | 2959 fps | 97.1% |
| Somchem S355 | <<locked>> | 84% | 47,805 psi | 87% | 3012 fps | 99.8% |
| Somchem S365 | <<locked>> | 92% | 46,920 psi | 85% | 3084 fps | 100% |
| Somchem S385 | <<locked>> | 96% | 49,777 psi | 90% | 3077 fps | 96.8% |
| Vihtavuori N150 | <<locked>> | 86% | 48,805 psi | 88% | 2989 fps | 100% |
| Vihtavuori N160 | <<locked>> | 88% | 47,007 psi | 85% | 3018 fps | 98.9% |
| Vihtavuori N165ᴾ | <<locked>> | 100% | 48,834 psi | 88% | 3045 fps | 96.2% |
| Vihtavuori N540 | <<locked>> | 82% | 49,980 psi | 90% | 3002 fps | 100% |
| Vihtavuori N550 | <<locked>> | 90% | 49,676 psi | 90% | 3081 fps | 99.1% |
| Vihtavuori N555 | <<locked>> | 98% | 49,632 psi | 90% | 3140 fps | 99.7% |
| Winchester 6.5 StaBALL | <<locked>> | 88% | 46,644 psi | 84% | 2986 fps | 99.9% |
| Winchester 760 | <<locked>> | 88% | 48,327 psi | 87% | 3084 fps | 97.1% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 42,728 psi | 77% | 3150 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 2700 | <<locked>> | 80% | 46,804 psi | 85% | 2936 fps | 95.8% |
| Accurate 3100 | <<locked>> | 92% | 38,319 psi | 69% | 2841 fps | 95.3% |
| Accurate 4064 | <<locked>> | 80% | 46,137 psi | 83% | 2959 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 34,606 psi | 63% | 2772 fps | 95.8% |
| ADI AR 2208 | <<locked>> | 80% | 43,859 psi | 79% | 2920 fps | 98.8% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 44,106 psi | 80% | 2946 fps | 99.7% |
| Alliant Reloder-16 | <<locked>> | 80% | 34,200 psi | 62% | 2785 fps | 95.8% |
| Alliant Reloder-17 | <<locked>> | 80% | 38,464 psi | 70% | 2923 fps | 98.8% |
| Alliant Reloder-23 | <<locked>> | 86% | 30,110 psi | 54% | 2684 fps | 95.7% |
| Alliant Reloder-25 | <<locked>> | 96% | 36,521 psi | 66% | 2874 fps | 95% |
| Alliant Reloder-26 | 46.4 gr | 88% | 35,128 psi | 64% | 2887 fps | 95.4% |
| Bofors RP3 | <<locked>> | 80% | 44,077 psi | 80% | 2953 fps | 99.7% |
| Bofors RP7 | <<locked>> | 84% | 44,411 psi | 80% | 2923 fps | 95.4% |
| Hodgdon H380 | <<locked>> | 80% | 44,802 psi | 81% | 2963 fps | 98.2% |
| Hodgdon H414 | <<locked>> | 84% | 41,959 psi | 76% | 2949 fps | 95.3% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 31,560 psi | 57% | 2674 fps | 96.6% |
| Hodgdon Superformance | <<locked>> | 86% | 44,440 psi | 80% | 3031 fps | 95.6% |
| Hodgdon TrailBoss | <<locked>> | 80% | 26,890 psi | 49% | 1778 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 46,122 psi | 83% | 2959 fps | 99.3% |
| IMR 4350 | <<locked>> | 88% | 45,063 psi | 82% | 2959 fps | 95.6% |
| IMR 4451 Enduron | <<locked>> | 82% | 43,134 psi | 78% | 2900 fps | 95.5% |
| IMR 4831 | <<locked>> | 80% | 33,576 psi | 61% | 2726 fps | 95.5% |
| Lovex S062 | <<locked>> | 80% | 46,006 psi | 83% | 2956 fps | 99.9% |
| Lovex S065 | <<locked>> | 80% | 38,189 psi | 69% | 2789 fps | 95.6% |
| Lovex S070 | <<locked>> | 84% | 41,176 psi | 75% | 2877 fps | 95.3% |
| Lovex S071 | <<locked>> | 98% | 39,160 psi | 71% | 2858 fps | 95.6% |
| Norma 203B | <<locked>> | 80% | 46,398 psi | 84% | 3005 fps | 99.6% |
| Norma MRP | 48.1 gr | 94% | 43,352 psi | 78% | 3058 fps | 95.6% |
| Norma URP | <<locked>> | 80% | 34,693 psi | 63% | 2772 fps | 95.7% |
| Ramshot Big Game | <<locked>> | 80% | 46,688 psi | 84% | 3025 fps | 99.5% |
| Ramshot Hunter | <<locked>> | 84% | 38,522 psi | 70% | 2877 fps | 95.2% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,441 psi | 50% | 1824 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 44,860 psi | 81% | 2940 fps | 96.8% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 40,901 psi | 74% | 2995 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 34,432 psi | 62% | 2789 fps | 95.3% |
| ReloadSwiss RS 70 | 42.8 gr | 82% | 36,187 psi | 65% | 2854 fps | 95.3% |
| Rottweil R 903 | <<locked>> | 80% | 41,611 psi | 75% | 2894 fps | 99.3% |
| Rottweil R 907 | <<locked>> | 84% | 44,411 psi | 80% | 2923 fps | 95.4% |
| Shooters World Long Rifle | <<locked>> | 80% | 38,189 psi | 69% | 2789 fps | 95.6% |
| Shooters World Precision | <<locked>> | 80% | 46,006 psi | 83% | 2956 fps | 99.9% |
| Shooters World SW4350 | <<locked>> | 84% | 41,176 psi | 75% | 2877 fps | 95.3% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 42,670 psi | 77% | 2949 fps | 99% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 43,236 psi | 78% | 2818 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 84% | 42,670 psi | 77% | 2844 fps | 95.6% |
| Somchem S355 | <<locked>> | 80% | 42,134 psi | 76% | 2900 fps | 99.3% |
| Somchem S365 | <<locked>> | 80% | 31,198 psi | 56% | 2720 fps | 97.9% |
| Somchem S385 | <<locked>> | 92% | 43,540 psi | 79% | 2953 fps | 95.1% |
| Vihtavuori N150 | <<locked>> | 80% | 40,147 psi | 73% | 2825 fps | 99.7% |
| Vihtavuori N160 | <<locked>> | 80% | 36,042 psi | 65% | 2776 fps | 96.2% |
| Vihtavuori N165 | <<locked>> | 98% | 45,614 psi | 83% | 2982 fps | 95.3% |
| Vihtavuori N540 | <<locked>> | 80% | 46,833 psi | 85% | 2949 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 35,679 psi | 65% | 2776 fps | 95.8% |
| Vihtavuori N555 | <<locked>> | 84% | 31,067 psi | 56% | 2713 fps | 95% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 35,491 psi | 64% | 2746 fps | 98.3% |
| Winchester 760 | <<locked>> | 84% | 42,279 psi | 77% | 2956 fps | 95.4% |
| Winchester StaBALL HD | <<locked>> | 88% | 28,500 psi | 52% | 2710 fps | 95.4% |
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 56 powders for .243 Ackley Improved loaded with the .243 | 90gr | Sierra FMJBT GameKing. Norma MRP delivers the highest muzzle velocity at 3,192 fps; across all powders the maximum-charge window runs from 1,988 fps to 3,192 fps. Alliant Reloder-23 gives the best case fill at 100 %, and 56 of the 56 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (381 MPa), the top charges use 65–90 %, leaving at least 10 % headroom. The 90.0 gr projectile in 0.243" calls for a 1:11.0 twist; slower twists will usually not stabilise this weight. Alliant Reloder-23, Alliant Reloder-25, 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, ReloadSwiss RS 70, Norma MRP rank at the top here: for .243 Ackley Improved with the .243 | 90gr | Sierra FMJBT 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.