Load Specifications
Load data in caliber .243 Ackley Improved with .243 | 77gr | Lapua Open Tip 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>> | 98% | 49,995 psi | 90% | 2874 fps | 99.2% |
| Accurate 4350 | <<locked>> | 88% | 48,631 psi | 88% | 2871 fps | 99.8% |
| ADI AR 2208 | <<locked>> | 82% | 48,950 psi | 89% | 2808 fps | 99.9% |
| ADI AR 2209 | <<locked>> | 92% | 46,920 psi | 85% | 2854 fps | 96.3% |
| Alliant Power Pro Varmint | <<locked>> | 94% | 49,995 psi | 90% | 2910 fps | 97.2% |
| Alliant Reloder- TS 15.5 | <<locked>> | 82% | 49,574 psi | 90% | 2831 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 90% | 49,835 psi | 90% | 2936 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 84% | 47,137 psi | 85% | 2897 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 94% | 49,356 psi | 89% | 2900 fps | 97.1% |
| Alliant Reloder-22 | <<locked>> | 98% | 49,792 psi | 90% | 2956 fps | 97.4% |
| Alliant Reloder-23 | <<locked>> | 98% | 47,297 psi | 86% | 2900 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 43,830 psi | 79% | 2867 fps | 99% |
| Alliant Reloder-26 | <<locked>> | 96% | 49,995 psi | 90% | 3025 fps | 99.9% |
| Bofors RP15ᴾ | <<locked>> | 100% | 49,008 psi | 89% | 2936 fps | 97% |
| Bofors RP3 | <<locked>> | 82% | 49,980 psi | 90% | 2844 fps | 100% |
| Bofors RP5 | <<locked>> | 98% | 49,792 psi | 90% | 2956 fps | 97.4% |
| Bofors RP7 | <<locked>> | 86% | 49,719 psi | 90% | 2825 fps | 98% |
| Hodgdon H414 | <<locked>> | 86% | 47,834 psi | 87% | 2867 fps | 98.2% |
| Hodgdon H4350 | <<locked>> | 84% | 47,688 psi | 86% | 2822 fps | 96.9% |
| Hodgdon Hybrid 100V | <<locked>> | 90% | 46,833 psi | 85% | 2808 fps | 100% |
| Hodgdon Superformance | <<locked>> | 86% | 47,036 psi | 85% | 2887 fps | 97.8% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,303 psi | 66% | 1827 fps | 100% |
| IMR 4350 | <<locked>> | 88% | 47,384 psi | 86% | 2802 fps | 97.6% |
| IMR 4451 Enduron | <<locked>> | 84% | 48,037 psi | 87% | 2799 fps | 98% |
| IMR 4831 | <<locked>> | 90% | 49,501 psi | 90% | 2871 fps | 99.9% |
| Lovex S065 | <<locked>> | 86% | 48,399 psi | 88% | 2802 fps | 99.1% |
| Lovex S070 | <<locked>> | 88% | 49,313 psi | 89% | 2838 fps | 98.5% |
| Lovex S071ᴾ | <<locked>> | 100% | 44,701 psi | 81% | 2782 fps | 98.4% |
| Norma 204 | <<locked>> | 88% | 47,616 psi | 86% | 2848 fps | 96.4% |
| Norma MRP | <<locked>> | 96% | 49,168 psi | 89% | 2976 fps | 98.5% |
| Norma URP | <<locked>> | 88% | 47,950 psi | 87% | 2861 fps | 99.7% |
| Ramshot Hunter | <<locked>> | 90% | 49,893 psi | 90% | 2910 fps | 99.1% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 46,528 psi | 84% | 2874 fps | 97.2% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 36,970 psi | 67% | 1870 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 82% | 46,586 psi | 84% | 2890 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 88% | 48,660 psi | 88% | 2894 fps | 99.7% |
| ReloadSwiss RS 70 | <<locked>> | 88% | 47,239 psi | 85% | 2913 fps | 99.5% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 42,975 psi | 78% | 2890 fps | 97.2% |
| Rottweil R 903 | <<locked>> | 82% | 47,079 psi | 85% | 2789 fps | 100% |
| Rottweil R 905 | <<locked>> | 94% | 48,573 psi | 88% | 2887 fps | 97.1% |
| Rottweil R 907 | <<locked>> | 86% | 49,719 psi | 90% | 2825 fps | 98% |
| Shooters World Long Rifle | <<locked>> | 86% | 48,399 psi | 88% | 2802 fps | 99.1% |
| Shooters World SW4350 | <<locked>> | 88% | 49,313 psi | 89% | 2838 fps | 98.5% |
| SNPE Vectan SP 11 | <<locked>> | 82% | 48,167 psi | 87% | 2844 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 82% | 48,124 psi | 87% | 2687 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 86% | 47,645 psi | 86% | 2746 fps | 98.1% |
| SNPE Vectan Tubal 8000 | <<locked>> | 94% | 48,138 psi | 87% | 2881 fps | 96.9% |
| Somchem S355 | <<locked>> | 82% | 47,340 psi | 86% | 2789 fps | 100% |
| Somchem S365 | <<locked>> | 90% | 46,862 psi | 85% | 2864 fps | 100% |
| Somchem S385 | <<locked>> | 94% | 49,284 psi | 89% | 2867 fps | 97.9% |
| Vihtavuori N150 | <<locked>> | 84% | 48,211 psi | 87% | 2766 fps | 100% |
| Vihtavuori N160 | <<locked>> | 88% | 49,690 psi | 90% | 2854 fps | 99.8% |
| Vihtavuori N165 | <<locked>> | 98% | 48,254 psi | 87% | 2835 fps | 97.4% |
| Vihtavuori N550 | <<locked>> | 88% | 48,965 psi | 89% | 2858 fps | 99.7% |
| Vihtavuori N555 | <<locked>> | 96% | 49,705 psi | 90% | 2923 fps | 100% |
| Winchester 6.5 StaBALL | <<locked>> | 88% | 49,095 psi | 89% | 2822 fps | 100% |
| Winchester 760 | <<locked>> | 86% | 47,834 psi | 87% | 2867 fps | 98.2% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 45,672 psi | 83% | 3012 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 96% | 48,834 psi | 88% | 2848 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% | 33,286 psi | 60% | 2533 fps | 95% |
| Accurate 4350 | <<locked>> | 80% | 37,144 psi | 67% | 2641 fps | 98% |
| ADI AR 2208 | <<locked>> | 80% | 46,006 psi | 83% | 2756 fps | 99.7% |
| ADI AR 2209 | <<locked>> | 90% | 43,685 psi | 79% | 2789 fps | 95.4% |
| Alliant Power Pro Varmint | <<locked>> | 90% | 44,048 psi | 80% | 2795 fps | 95.6% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 46,528 psi | 84% | 2779 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 80% | 36,158 psi | 65% | 2651 fps | 98.1% |
| Alliant Reloder-17 | <<locked>> | 80% | 41,046 psi | 74% | 2782 fps | 99.9% |
| Alliant Reloder-19 | <<locked>> | 90% | 43,540 psi | 79% | 2789 fps | 95.5% |
| Alliant Reloder-22 | <<locked>> | 94% | 43,743 psi | 79% | 2838 fps | 95.8% |
| Alliant Reloder-23 | <<locked>> | 80% | 26,571 psi | 48% | 2398 fps | 95.6% |
| Alliant Reloder-25 | <<locked>> | 92% | 34,171 psi | 62% | 2635 fps | 95.9% |
| Alliant Reloder-26 | 41.6 gr | 84% | 32,460 psi | 59% | 2631 fps | 96.1% |
| Bofors RP15 | <<locked>> | 96% | 42,830 psi | 78% | 2815 fps | 95.3% |
| Bofors RP3 | <<locked>> | 80% | 46,862 psi | 85% | 2792 fps | 100% |
| Bofors RP5 | <<locked>> | 94% | 43,743 psi | 79% | 2838 fps | 95.8% |
| Bofors RP7 | <<locked>> | 80% | 41,234 psi | 75% | 2657 fps | 95.9% |
| Hodgdon H414 | <<locked>> | 80% | 38,957 psi | 70% | 2684 fps | 95.9% |
| Hodgdon H4350 | <<locked>> | 80% | 42,076 psi | 76% | 2710 fps | 95.4% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 33,779 psi | 61% | 2546 fps | 98.7% |
| Hodgdon Superformance | <<locked>> | 80% | 38,043 psi | 69% | 2694 fps | 95.1% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,122 psi | 49% | 1631 fps | 100% |
| IMR 4350 | <<locked>> | 82% | 39,320 psi | 71% | 2638 fps | 95.4% |
| IMR 4451 Enduron | <<locked>> | 80% | 42,496 psi | 77% | 2687 fps | 96.8% |
| IMR 4831 | <<locked>> | 80% | 35,607 psi | 64% | 2592 fps | 97.7% |
| Lovex S065 | <<locked>> | 80% | 40,205 psi | 73% | 2641 fps | 97.6% |
| Lovex S070 | <<locked>> | 80% | 38,450 psi | 70% | 2621 fps | 96% |
| Lovex S071 | <<locked>> | 92% | 34,534 psi | 62% | 2562 fps | 95.5% |
| Norma 204 | <<locked>> | 86% | 44,353 psi | 80% | 2782 fps | 95.5% |
| Norma MRP | 42.3 gr | 88% | 37,434 psi | 68% | 2726 fps | 95.1% |
| Norma URP | <<locked>> | 80% | 36,999 psi | 67% | 2638 fps | 97.9% |
| Ramshot Hunter | <<locked>> | 80% | 35,839 psi | 65% | 2621 fps | 95.8% |
| Ramshot Magnum | <<locked>> | 96% | 40,350 psi | 73% | 2746 fps | 95.3% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,789 psi | 50% | 1677 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 43,598 psi | 79% | 2838 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 36,738 psi | 66% | 2654 fps | 97.6% |
| ReloadSwiss RS 70 | 39.3 gr | 80% | 35,882 psi | 65% | 2664 fps | 96.9% |
| ReloadSwiss RS 76 | <<locked>> | 98% | 40,045 psi | 72% | 2818 fps | 96.1% |
| Rottweil R 903 | <<locked>> | 80% | 44,121 psi | 80% | 2736 fps | 100% |
| Rottweil R 905 | <<locked>> | 90% | 42,293 psi | 77% | 2762 fps | 95.3% |
| Rottweil R 907 | <<locked>> | 80% | 41,234 psi | 75% | 2657 fps | 95.9% |
| Shooters World Long Rifle | <<locked>> | 80% | 40,205 psi | 73% | 2641 fps | 97.6% |
| Shooters World SW4350 | <<locked>> | 80% | 38,450 psi | 70% | 2621 fps | 96% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 45,208 psi | 82% | 2789 fps | 99.9% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 45,440 psi | 82% | 2644 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 39,131 psi | 71% | 2579 fps | 96% |
| SNPE Vectan Tubal 8000 | <<locked>> | 90% | 41,901 psi | 76% | 2759 fps | 95.2% |
| Somchem S355 | <<locked>> | 80% | 44,454 psi | 80% | 2736 fps | 99.9% |
| Somchem S365 | <<locked>> | 80% | 33,446 psi | 61% | 2595 fps | 99.5% |
| Somchem S385 | <<locked>> | 88% | 40,451 psi | 73% | 2694 fps | 95.7% |
| Vihtavuori N150 | <<locked>> | 80% | 42,424 psi | 77% | 2664 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 38,363 psi | 69% | 2635 fps | 98.2% |
| Vihtavuori N165 | <<locked>> | 92% | 39,755 psi | 72% | 2667 fps | 95% |
| Vihtavuori N550 | <<locked>> | 80% | 37,855 psi | 69% | 2638 fps | 97.9% |
| Vihtavuori N555 | <<locked>> | 80% | 29,022 psi | 53% | 2470 fps | 95.7% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 37,521 psi | 68% | 2605 fps | 99.6% |
| Winchester 760 | <<locked>> | 80% | 39,204 psi | 71% | 2690 fps | 96% |
| Winchester StaBALL HD | <<locked>> | 82% | 24,947 psi | 45% | 2418 fps | 95% |
| Winchester Supreme 780 | <<locked>> | 92% | 42,424 psi | 77% | 2730 fps | 95.1% |
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 | 77gr | Lapua Open Tip. Alliant Reloder-26 delivers the highest muzzle velocity at 3,025 fps; across all powders the maximum-charge window runs from 1,827 fps to 3,025 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 105.0 gr projectile in 0.243" calls for a 1:8.0 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 | 77gr | Lapua Open Tip 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.