Load Specifications
Load data in caliber .243 Ackley Improved with .243 | 105gr | Speer Spitzer Soft Point bullet and 58 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 Winchester StaBALL HD.
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% | 48,907 psi | 89% | 2861 fps | 99.2% |
| Accurate 4350 | <<locked>> | 86% | 47,268 psi | 86% | 2851 fps | 99.7% |
| Accurate High Country | <<locked>> | 94% | 49,835 psi | 90% | 2995 fps | 96.4% |
| ADI AR 2209 | <<locked>> | 92% | 48,240 psi | 87% | 2890 fps | 96.9% |
| Alliant Power Pro Varmint | <<locked>> | 92% | 48,646 psi | 88% | 2894 fps | 97% |
| Alliant Reloder-16 | <<locked>> | 88% | 48,428 psi | 88% | 2917 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 84% | 48,805 psi | 88% | 2933 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 92% | 48,037 psi | 87% | 2884 fps | 97% |
| Alliant Reloder-22 | <<locked>> | 96% | 48,660 psi | 88% | 2940 fps | 97.3% |
| Alliant Reloder-23 | <<locked>> | 98% | 49,182 psi | 89% | 2936 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 45,600 psi | 83% | 2913 fps | 99.4% |
| Alliant Reloder-26 | <<locked>> | 94% | 48,805 psi | 88% | 3009 fps | 99.9% |
| Bofors RP15 | <<locked>> | 98% | 47,645 psi | 86% | 2920 fps | 96.9% |
| Bofors RP5 | <<locked>> | 96% | 48,660 psi | 88% | 2940 fps | 97.3% |
| Bofors RP7 | <<locked>> | 84% | 47,950 psi | 87% | 2802 fps | 97.8% |
| Hodgdon H414 | <<locked>> | 86% | 49,429 psi | 89% | 2904 fps | 98.6% |
| Hodgdon H4350 | <<locked>> | 84% | 49,255 psi | 89% | 2864 fps | 97.5% |
| Hodgdon Hybrid 100V | <<locked>> | 90% | 48,544 psi | 88% | 2844 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 44,585 psi | 81% | 2943 fps | 96.9% |
| Hodgdon Superformance | <<locked>> | 86% | 49,066 psi | 89% | 2933 fps | 98.3% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,405 psi | 66% | 1841 fps | 100% |
| IMR 4350 | <<locked>> | 88% | 48,805 psi | 88% | 2838 fps | 98% |
| IMR 4451 Enduron | <<locked>> | 84% | 49,574 psi | 90% | 2835 fps | 98.5% |
| IMR 4831 | <<locked>> | 88% | 48,066 psi | 87% | 2851 fps | 99.8% |
| Lovex S065 | <<locked>> | 86% | 49,647 psi | 90% | 2831 fps | 99.4% |
| Lovex S070 | <<locked>> | 86% | 47,848 psi | 87% | 2822 fps | 98.4% |
| Lovex S071ᴾ | <<locked>> | 100% | 46,485 psi | 84% | 2818 fps | 98.8% |
| Norma 204 | <<locked>> | 88% | 49,066 psi | 89% | 2881 fps | 97% |
| Norma MRP | <<locked>> | 94% | 48,109 psi | 87% | 2963 fps | 98.4% |
| Norma URP | <<locked>> | 88% | 49,617 psi | 90% | 2894 fps | 99.9% |
| Ramshot Hunter | <<locked>> | 88% | 48,327 psi | 87% | 2890 fps | 99% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 48,559 psi | 88% | 2920 fps | 97.9% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,072 psi | 67% | 1883 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 82% | 48,327 psi | 87% | 2923 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 86% | 47,224 psi | 85% | 2874 fps | 99.6% |
| ReloadSwiss RS 70 | <<locked>> | 88% | 48,936 psi | 89% | 2953 fps | 99.8% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 44,715 psi | 81% | 2940 fps | 98% |
| Rottweil R 903 | <<locked>> | 82% | 48,544 psi | 88% | 2822 fps | 100% |
| Rottweil R 905 | <<locked>> | 92% | 46,978 psi | 85% | 2864 fps | 96.9% |
| Rottweil R 907 | <<locked>> | 84% | 47,950 psi | 87% | 2802 fps | 97.8% |
| Shooters World Long Rifle | <<locked>> | 86% | 49,647 psi | 90% | 2831 fps | 99.4% |
| Shooters World SW4350 | <<locked>> | 86% | 47,848 psi | 87% | 2822 fps | 98.4% |
| SNPE Vectan SP 11 | <<locked>> | 82% | 49,850 psi | 90% | 2877 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 82% | 49,545 psi | 90% | 2717 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 86% | 49,052 psi | 89% | 2782 fps | 98.5% |
| SNPE Vectan Tubal 8000 | <<locked>> | 94% | 49,951 psi | 90% | 2920 fps | 97.5% |
| Somchem S355 | <<locked>> | 82% | 48,747 psi | 88% | 2822 fps | 100% |
| Somchem S365 | <<locked>> | 90% | 48,979 psi | 89% | 2900 fps | 100% |
| Somchem S385 | <<locked>> | 92% | 47,993 psi | 87% | 2851 fps | 97.9% |
| Vihtavuori N150 | <<locked>> | 84% | 49,574 psi | 90% | 2792 fps | 100% |
| Vihtavuori N160 | <<locked>> | 86% | 48,211 psi | 87% | 2835 fps | 99.8% |
| Vihtavuori N165 | <<locked>> | 96% | 47,181 psi | 85% | 2825 fps | 97.3% |
| Vihtavuori N550 | <<locked>> | 86% | 47,543 psi | 86% | 2841 fps | 99.6% |
| Vihtavuori N555 | <<locked>> | 94% | 48,515 psi | 88% | 2910 fps | 100% |
| Winchester 6.5 StaBALL | <<locked>> | 86% | 47,442 psi | 86% | 2802 fps | 100% |
| Winchester 760 | <<locked>> | 86% | 49,429 psi | 89% | 2904 fps | 98.6% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 47,761 psi | 86% | 3051 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 94% | 47,630 psi | 86% | 2838 fps | 96.8% |
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>> | 86% | 34,708 psi | 63% | 2572 fps | 95.7% |
| Accurate 4350 | <<locked>> | 80% | 38,566 psi | 70% | 2677 fps | 98.5% |
| Accurate High Country | <<locked>> | 92% | 46,485 psi | 84% | 2930 fps | 95.5% |
| ADI AR 2209 | <<locked>> | 88% | 42,308 psi | 77% | 2769 fps | 95.2% |
| Alliant Power Pro Varmint | <<locked>> | 88% | 42,699 psi | 77% | 2776 fps | 95.4% |
| Alliant Reloder-16 | <<locked>> | 80% | 37,405 psi | 68% | 2687 fps | 98.6% |
| Alliant Reloder-17 | <<locked>> | 80% | 42,366 psi | 77% | 2812 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 88% | 42,221 psi | 76% | 2766 fps | 95.3% |
| Alliant Reloder-22 | <<locked>> | 92% | 42,670 psi | 77% | 2822 fps | 95.7% |
| Alliant Reloder-23 | <<locked>> | 80% | 27,398 psi | 50% | 2431 fps | 96.3% |
| Alliant Reloder-25 | <<locked>> | 90% | 33,199 psi | 60% | 2615 fps | 95.6% |
| Alliant Reloder-26 | 41.9 gr | 82% | 31,401 psi | 57% | 2605 fps | 95.7% |
| Bofors RP15 | <<locked>> | 94% | 41,800 psi | 76% | 2799 fps | 95.2% |
| Bofors RP5 | <<locked>> | 92% | 42,670 psi | 77% | 2822 fps | 95.7% |
| Bofors RP7 | <<locked>> | 80% | 42,453 psi | 77% | 2694 fps | 96.5% |
| Hodgdon H414 | <<locked>> | 80% | 40,509 psi | 73% | 2726 fps | 96.6% |
| Hodgdon H4350 | <<locked>> | 80% | 43,308 psi | 78% | 2746 fps | 96% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 34,867 psi | 63% | 2575 fps | 99% |
| Hodgdon Retumbo | <<locked>> | 98% | 41,930 psi | 76% | 2881 fps | 95.9% |
| Hodgdon Superformance | <<locked>> | 80% | 39,349 psi | 71% | 2733 fps | 95.8% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,209 psi | 49% | 1644 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 38,101 psi | 69% | 2618 fps | 95.2% |
| IMR 4451 Enduron | <<locked>> | 80% | 43,714 psi | 79% | 2723 fps | 97.3% |
| IMR 4831 | <<locked>> | 80% | 36,898 psi | 67% | 2628 fps | 98.2% |
| Lovex S065 | <<locked>> | 80% | 41,220 psi | 75% | 2671 fps | 98% |
| Lovex S070 | <<locked>> | 80% | 39,682 psi | 72% | 2654 fps | 96.6% |
| Lovex S071 | <<locked>> | 90% | 33,736 psi | 61% | 2546 fps | 95.3% |
| Norma 204 | <<locked>> | 84% | 43,004 psi | 78% | 2762 fps | 95.3% |
| Norma MRP | 43.7 gr | 88% | 39,001 psi | 71% | 2769 fps | 96% |
| Norma URP | <<locked>> | 80% | 38,334 psi | 69% | 2674 fps | 98.3% |
| Ramshot Hunter | <<locked>> | 80% | 37,014 psi | 67% | 2654 fps | 96.4% |
| Ramshot Magnum | <<locked>> | 94% | 39,073 psi | 71% | 2726 fps | 95.1% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,876 psi | 50% | 1690 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 45,005 psi | 81% | 2867 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 38,276 psi | 69% | 2694 fps | 98.2% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 37,188 psi | 67% | 2703 fps | 97.6% |
| ReloadSwiss RS 76 | <<locked>> | 96% | 38,943 psi | 70% | 2802 fps | 95.9% |
| Rottweil R 903 | <<locked>> | 80% | 45,614 psi | 83% | 2772 fps | 100% |
| Rottweil R 905 | <<locked>> | 88% | 41,394 psi | 75% | 2749 fps | 95.3% |
| Rottweil R 907 | <<locked>> | 80% | 42,453 psi | 77% | 2694 fps | 96.5% |
| Shooters World Long Rifle | <<locked>> | 80% | 41,220 psi | 75% | 2671 fps | 98% |
| Shooters World SW4350 | <<locked>> | 80% | 39,682 psi | 72% | 2654 fps | 96.6% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 46,557 psi | 84% | 2822 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 46,557 psi | 84% | 2671 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 40,567 psi | 73% | 2618 fps | 96.7% |
| SNPE Vectan Tubal 8000 | <<locked>> | 88% | 41,017 psi | 74% | 2746 fps | 95.1% |
| Somchem S355 | <<locked>> | 80% | 45,571 psi | 82% | 2762 fps | 100% |
| Somchem S365 | <<locked>> | 80% | 34,780 psi | 63% | 2628 fps | 99.8% |
| Somchem S385 | <<locked>> | 86% | 39,378 psi | 71% | 2677 fps | 95.6% |
| Vihtavuori N150 | <<locked>> | 80% | 43,772 psi | 79% | 2694 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 39,697 psi | 72% | 2671 fps | 98.6% |
| Vihtavuori N165 | <<locked>> | 92% | 41,336 psi | 75% | 2710 fps | 95.8% |
| Vihtavuori N550 | <<locked>> | 80% | 39,088 psi | 71% | 2671 fps | 98.3% |
| Vihtavuori N555 | <<locked>> | 80% | 30,313 psi | 55% | 2510 fps | 96.5% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 38,769 psi | 70% | 2638 fps | 99.8% |
| Winchester 760 | <<locked>> | 80% | 40,509 psi | 73% | 2726 fps | 96.6% |
| Winchester StaBALL HD | 40.3 gr | 82% | 25,933 psi | 47% | 2464 fps | 96.2% |
| Winchester Supreme 780 | <<locked>> | 90% | 41,263 psi | 75% | 2713 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 58 powders for .243 Ackley Improved loaded with the .243 | 105gr | Speer Spitzer Soft Point. Winchester StaBALL HD delivers the highest muzzle velocity at 3,051 fps; across all powders the maximum-charge window runs from 1,841 fps to 3,051 fps. Alliant Reloder-25 gives the best case fill at 100 %, and 58 of the 58 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 105.0 gr projectile in 0.243" calls for a 1:10.0 twist; slower twists will usually not stabilise this weight. Alliant Reloder-25, Hodgdon Retumbo, 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. Norma MRP, Alliant Reloder-26, Winchester StaBALL HD rank at the top here: for .243 Ackley Improved with the .243 | 105gr | Speer Spitzer Soft Point 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.