Load Specifications
Load data in caliber .243 Ackley Improved with .243 | 89gr | Merlin Virtus bullet and 60 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are ReloadSwiss RS 70, Alliant Reloder-17 and Alliant Reloder-26.
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 2495 | <<locked>> | 82% | 47,863 psi | 87% | 2963 fps | 100% |
| Accurate 3100ᴾ | <<locked>> | 100% | 45,948 psi | 83% | 3015 fps | 97.2% |
| Accurate 4064 | <<locked>> | 84% | 48,283 psi | 87% | 3015 fps | 100% |
| Accurate 4350 | <<locked>> | 92% | 48,588 psi | 88% | 3097 fps | 99% |
| ADI AR 2208 | <<locked>> | 86% | 49,661 psi | 90% | 3045 fps | 99.4% |
| Alliant Power Pro 2000-MR | <<locked>> | 82% | 47,776 psi | 86% | 3150 fps | 99.3% |
| Alliant Reloder- TS 15.5 | <<locked>> | 86% | 49,690 psi | 90% | 3068 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 82% | 46,862 psi | 85% | 3028 fps | 99.2% |
| Alliant Reloder-16 | <<locked>> | 94% | 49,792 psi | 90% | 3163 fps | 99.5% |
| Alliant Reloder-17 | <<locked>> | 88% | 47,282 psi | 86% | 3130 fps | 99.9% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 43,540 psi | 79% | 3048 fps | 99.5% |
| Alliant Reloder-26ᴾ | <<locked>> | 100% | 49,821 psi | 90% | 3245 fps | 99.3% |
| Bofors RP3 | <<locked>> | 84% | 46,847 psi | 85% | 3022 fps | 99.8% |
| Hodgdon H380 | <<locked>> | 84% | 47,485 psi | 86% | 3028 fps | 98.4% |
| Hodgdon H414 | <<locked>> | 90% | 47,805 psi | 87% | 3084 fps | 96.6% |
| Hodgdon Hybrid 100V | <<locked>> | 96% | 49,966 psi | 90% | 3094 fps | 99.9% |
| Hodgdon LEVERevolution | <<locked>> | 82% | 48,370 psi | 88% | 3081 fps | 99.9% |
| Hodgdon Superformance | <<locked>> | 90% | 47,630 psi | 86% | 3107 fps | 96.1% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 35,824 psi | 65% | 1985 fps | 100% |
| IMR 4064 | <<locked>> | 84% | 49,081 psi | 89% | 3028 fps | 99.5% |
| IMR 4166 Enduron | <<locked>> | 82% | 48,675 psi | 88% | 2999 fps | 96.7% |
| IMR 4350 | <<locked>> | 92% | 47,834 psi | 87% | 3022 fps | 96% |
| IMR 4451 Enduron | <<locked>> | 88% | 49,168 psi | 89% | 3031 fps | 96.7% |
| IMR 4831 | <<locked>> | 94% | 49,269 psi | 89% | 3091 fps | 99.2% |
| IMR 4895 | <<locked>> | 82% | 48,095 psi | 87% | 3061 fps | 99.6% |
| Lovex S062 | <<locked>> | 84% | 49,023 psi | 89% | 3028 fps | 100% |
| Lovex S065 | <<locked>> | 90% | 48,689 psi | 88% | 3025 fps | 98% |
| Lovex S070 | <<locked>> | 92% | 49,603 psi | 90% | 3061 fps | 97.2% |
| Norma 203B | <<locked>> | 84% | 49,559 psi | 90% | 3077 fps | 99.7% |
| Norma MRPᴾ | <<locked>> | 100% | 49,182 psi | 89% | 3192 fps | 96.9% |
| Norma URP | <<locked>> | 92% | 47,950 psi | 87% | 3084 fps | 98.9% |
| Ramshot Big Game | <<locked>> | 82% | 46,340 psi | 84% | 3031 fps | 99.3% |
| Ramshot Hunter | <<locked>> | 94% | 49,937 psi | 90% | 3133 fps | 97.9% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 36,303 psi | 66% | 2031 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 84% | 48,037 psi | 87% | 3015 fps | 97.2% |
| ReloadSwiss RS 60 | <<locked>> | 86% | 46,949 psi | 85% | 3133 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 92% | 48,240 psi | 87% | 3114 fps | 98.8% |
| ReloadSwiss RS 70 | <<locked>> | 92% | 47,659 psi | 86% | 3136 fps | 98.5% |
| Rottweil R 902 | <<locked>> | 82% | 47,718 psi | 86% | 2986 fps | 99.9% |
| Rottweil R 903 | <<locked>> | 86% | 47,036 psi | 85% | 3022 fps | 99.8% |
| Shooters World Long Rifle | <<locked>> | 90% | 48,689 psi | 88% | 3025 fps | 98% |
| Shooters World Precision | <<locked>> | 84% | 49,023 psi | 89% | 3028 fps | 100% |
| Shooters World SW4350 | <<locked>> | 92% | 49,603 psi | 90% | 3061 fps | 97.2% |
| SNPE Vectan SP 11 | <<locked>> | 86% | 48,501 psi | 88% | 3077 fps | 99.6% |
| SNPE Vectan Tubal 5000 | <<locked>> | 86% | 49,081 psi | 89% | 2933 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 90% | 48,356 psi | 88% | 2969 fps | 96.7% |
| Somchem S355 | <<locked>> | 86% | 47,297 psi | 86% | 3015 fps | 99.7% |
| Somchem S365 | <<locked>> | 96% | 49,676 psi | 90% | 3150 fps | 100% |
| Somchem S385 | <<locked>> | 98% | 49,066 psi | 89% | 3074 fps | 96.3% |
| Vihtavuori N135 | <<locked>> | 82% | 47,688 psi | 86% | 2956 fps | 100% |
| Vihtavuori N140 | <<locked>> | 82% | 48,370 psi | 88% | 2972 fps | 100% |
| Vihtavuori N150 | <<locked>> | 88% | 48,559 psi | 88% | 2999 fps | 100% |
| Vihtavuori N160 | <<locked>> | 90% | 46,731 psi | 85% | 3025 fps | 98.6% |
| Vihtavuori N540 | <<locked>> | 84% | 49,763 psi | 90% | 3012 fps | 100% |
| Vihtavuori N550 | <<locked>> | 92% | 49,197 psi | 89% | 3087 fps | 98.9% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 48,472 psi | 88% | 3133 fps | 99.4% |
| Winchester 6.5 StaBALL | <<locked>> | 90% | 46,470 psi | 84% | 2995 fps | 99.8% |
| Winchester 760 | <<locked>> | 90% | 48,138 psi | 87% | 3094 fps | 96.7% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 39,146 psi | 71% | 3068 fps | 99.7% |
| Winchester StaBALL Match | <<locked>> | 82% | 49,937 psi | 90% | 3071 fps | 99.9% |
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 2495 | <<locked>> | 80% | 44,512 psi | 81% | 2904 fps | 100% |
| Accurate 3100 | <<locked>> | 96% | 39,798 psi | 72% | 2887 fps | 95.4% |
| Accurate 4064 | <<locked>> | 80% | 42,163 psi | 76% | 2900 fps | 100% |
| Accurate 4350 | <<locked>> | 82% | 33,721 psi | 61% | 2762 fps | 95% |
| ADI AR 2208 | <<locked>> | 80% | 41,191 psi | 75% | 2874 fps | 98% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 44,469 psi | 80% | 3081 fps | 98.7% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 41,060 psi | 74% | 2897 fps | 99.2% |
| Alliant Reloder-15 | <<locked>> | 80% | 44,019 psi | 80% | 2969 fps | 98.7% |
| Alliant Reloder-16 | <<locked>> | 82% | 33,779 psi | 61% | 2785 fps | 95.2% |
| Alliant Reloder-17 | 39.7 gr | 80% | 35,534 psi | 64% | 2861 fps | 97.7% |
| Alliant Reloder-23 | <<locked>> | 90% | 31,473 psi | 57% | 2740 fps | 96% |
| Alliant Reloder-26 | 46.8 gr | 92% | 36,840 psi | 67% | 2946 fps | 95.8% |
| Bofors RP3 | <<locked>> | 80% | 40,799 psi | 74% | 2900 fps | 99.2% |
| Hodgdon H380 | <<locked>> | 80% | 41,510 psi | 75% | 2904 fps | 97.1% |
| Hodgdon H414 | <<locked>> | 88% | 44,512 psi | 81% | 3018 fps | 95.7% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 28,964 psi | 52% | 2608 fps | 95% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 45,382 psi | 82% | 3022 fps | 99.8% |
| Hodgdon Superformance | <<locked>> | 88% | 44,440 psi | 80% | 3041 fps | 95.2% |
| Hodgdon TrailBoss | <<locked>> | 80% | 26,614 psi | 48% | 1775 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 43,236 psi | 78% | 2913 fps | 98.7% |
| IMR 4166 Enduron | <<locked>> | 80% | 45,469 psi | 82% | 2933 fps | 95.9% |
| IMR 4350 | <<locked>> | 90% | 44,962 psi | 81% | 2966 fps | 95.2% |
| IMR 4451 Enduron | <<locked>> | 84% | 43,236 psi | 78% | 2910 fps | 95.1% |
| IMR 4831 | <<locked>> | 84% | 35,085 psi | 63% | 2782 fps | 95.7% |
| IMR 4895 | <<locked>> | 80% | 45,165 psi | 82% | 3005 fps | 99.3% |
| Lovex S062 | <<locked>> | 80% | 42,931 psi | 78% | 2910 fps | 99.6% |
| Lovex S065 | <<locked>> | 82% | 37,739 psi | 68% | 2789 fps | 95% |
| Lovex S070 | <<locked>> | 88% | 43,511 psi | 79% | 2940 fps | 95.6% |
| Norma 203B | <<locked>> | 80% | 43,381 psi | 79% | 2956 fps | 99% |
| Norma MRP | <<locked>> | 98% | 45,745 psi | 83% | 3120 fps | 96% |
| Norma URP | <<locked>> | 82% | 34,098 psi | 62% | 2772 fps | 95% |
| Ramshot Big Game | <<locked>> | 80% | 43,192 psi | 78% | 2966 fps | 98.9% |
| Ramshot Hunter | <<locked>> | 88% | 40,741 psi | 74% | 2940 fps | 95.5% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 26,847 psi | 49% | 1814 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 41,872 psi | 76% | 2887 fps | 95.6% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 37,840 psi | 68% | 2933 fps | 99.8% |
| ReloadSwiss RS 62 | <<locked>> | 84% | 36,303 psi | 66% | 2851 fps | 95.7% |
| ReloadSwiss RS 70 | 43.4 gr | 86% | 38,638 psi | 70% | 2930 fps | 95.9% |
| Rottweil R 902 | <<locked>> | 80% | 44,817 psi | 81% | 2930 fps | 99.8% |
| Rottweil R 903 | <<locked>> | 80% | 38,377 psi | 69% | 2838 fps | 98.5% |
| Shooters World Long Rifle | <<locked>> | 82% | 37,739 psi | 68% | 2789 fps | 95% |
| Shooters World Precision | <<locked>> | 80% | 42,931 psi | 78% | 2910 fps | 99.6% |
| Shooters World SW4350 | <<locked>> | 88% | 43,511 psi | 79% | 2940 fps | 95.6% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 39,523 psi | 72% | 2894 fps | 98.2% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 40,451 psi | 73% | 2779 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 86% | 42,308 psi | 77% | 2848 fps | 95.1% |
| Somchem S355 | <<locked>> | 80% | 38,856 psi | 70% | 2838 fps | 98.5% |
| Somchem S365 | <<locked>> | 80% | 28,471 psi | 52% | 2651 fps | 96.3% |
| Somchem S385 | <<locked>> | 96% | 45,687 psi | 83% | 3009 fps | 95.3% |
| Vihtavuori N135 | <<locked>> | 80% | 44,657 psi | 81% | 2907 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 45,411 psi | 82% | 2920 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 37,275 psi | 67% | 2772 fps | 99.1% |
| Vihtavuori N160 | <<locked>> | 82% | 35,534 psi | 64% | 2776 fps | 95.6% |
| Vihtavuori N540 | <<locked>> | 80% | 43,729 psi | 79% | 2904 fps | 100% |
| Vihtavuori N550 | <<locked>> | 82% | 35,157 psi | 64% | 2776 fps | 95.2% |
| Vihtavuori N555 | <<locked>> | 88% | 31,966 psi | 58% | 2756 fps | 95% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 33,025 psi | 60% | 2690 fps | 97.1% |
| Winchester 760 | <<locked>> | 88% | 44,860 psi | 81% | 3025 fps | 95.8% |
| Winchester StaBALL HD | <<locked>> | 92% | 29,776 psi | 54% | 2766 fps | 95.8% |
| Winchester StaBALL Match | <<locked>> | 80% | 46,586 psi | 84% | 3009 fps | 99.7% |
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 60 powders for .243 Ackley Improved loaded with the .243 | 89gr | Merlin Virtus. Alliant Reloder-26 delivers the highest muzzle velocity at 3,245 fps; across all powders the maximum-charge window runs from 1,985 fps to 3,245 fps. Accurate 3100 gives the best case fill at 100 %, and 60 of the 60 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 89.0 gr projectile in 0.243" calls for a 1:8.5 twist; slower twists will usually not stabilise this weight. Accurate 3100, Alliant Reloder-23, Alliant Reloder-26 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. ReloadSwiss RS 70, Alliant Reloder-17, Alliant Reloder-26 rank at the top here: for .243 Ackley Improved with the .243 | 89gr | Merlin Virtus 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.