Load Specifications
Load data in caliber .243 WSSM with .243 | 90gr | Impala RNFP KO bullet and 97 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 ReloadSwiss RS 60.
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 2495 | <<locked>> | 84% | 55,230 psi | 87% | 3022 fps | 100% |
| Accurate 2700 | <<locked>> | 86% | 55,245 psi | 87% | 3041 fps | 96.9% |
| Accurate 3100ᴾ | <<locked>> | 100% | 48,530 psi | 76% | 3015 fps | 97.4% |
| Accurate 4064 | <<locked>> | 86% | 54,868 psi | 86% | 3064 fps | 100% |
| Accurate 4350 | <<locked>> | 94% | 54,128 psi | 85% | 3146 fps | 99.5% |
| ADI AR 2206H | <<locked>> | 84% | 56,855 psi | 89% | 3136 fps | 100% |
| ADI AR 2208 | <<locked>> | 90% | 57,580 psi | 90% | 3130 fps | 99.9% |
| ADI AR 2209ᴾ | <<locked>> | 100% | 55,071 psi | 86% | 3166 fps | 96% |
| ADI Benchmark 8208 | <<locked>> | 82% | 55,477 psi | 87% | 3077 fps | 100% |
| Alliant AR-Comp | <<locked>> | 82% | 56,956 psi | 89% | 3054 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 86% | 56,492 psi | 89% | 3261 fps | 99.9% |
| Alliant Power Pro Varmintᴾ | <<locked>> | 100% | 54,694 psi | 86% | 3159 fps | 96% |
| Alliant Reloder- TS 15.5 | <<locked>> | 88% | 54,824 psi | 86% | 3107 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 86% | 55,390 psi | 87% | 3130 fps | 99.8% |
| Alliant Reloder-16 | <<locked>> | 96% | 54,331 psi | 85% | 3196 fps | 99.7% |
| Alliant Reloder-17 | <<locked>> | 92% | 55,767 psi | 87% | 3238 fps | 100% |
| Alliant Reloder-19ᴾ | <<locked>> | 100% | 53,954 psi | 85% | 3150 fps | 96% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 45,498 psi | 71% | 3045 fps | 99.6% |
| Alliant Reloder-26ᴾ | <<locked>> | 100% | 51,445 psi | 81% | 3232 fps | 99.3% |
| Baschieri & Pellagri 107 | <<locked>> | 84% | 56,304 psi | 88% | 3143 fps | 99.7% |
| Bofors RP3 | <<locked>> | 88% | 56,086 psi | 88% | 3130 fps | 100% |
| Bofors RP7 | <<locked>> | 92% | 55,448 psi | 87% | 3091 fps | 97.2% |
| Hodgdon Benchmark | <<locked>> | 82% | 56,652 psi | 89% | 3054 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 82% | 55,492 psi | 87% | 3110 fps | 100% |
| Hodgdon H380 | <<locked>> | 88% | 56,333 psi | 88% | 3136 fps | 99.4% |
| Hodgdon H414 | <<locked>> | 94% | 55,999 psi | 88% | 3186 fps | 98% |
| Hodgdon H4350 | <<locked>> | 92% | 56,231 psi | 88% | 3143 fps | 96.7% |
| Hodgdon H4895 | <<locked>> | 84% | 57,421 psi | 90% | 3146 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 98% | 54,520 psi | 85% | 3120 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 86% | 57,101 psi | 89% | 3179 fps | 100% |
| Hodgdon Superformance | <<locked>> | 94% | 56,405 psi | 88% | 3222 fps | 97.7% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,143 psi | 57% | 1946 fps | 100% |
| Hodgdon VARGET | <<locked>> | 84% | 54,897 psi | 86% | 3091 fps | 100% |
| IMR 3031 | <<locked>> | 84% | 57,609 psi | 90% | 3127 fps | 100% |
| IMR 4064 | <<locked>> | 88% | 57,058 psi | 89% | 3114 fps | 99.9% |
| IMR 4166 Enduron | <<locked>> | 86% | 56,898 psi | 89% | 3091 fps | 98% |
| IMR 4350 | <<locked>> | 96% | 55,593 psi | 87% | 3114 fps | 97.3% |
| IMR 4451 Enduron | <<locked>> | 92% | 56,913 psi | 89% | 3120 fps | 97.9% |
| IMR 4831 | <<locked>> | 96% | 54,650 psi | 86% | 3136 fps | 99.6% |
| IMR 4895 | <<locked>> | 86% | 56,768 psi | 89% | 3163 fps | 100% |
| IMR 8208 XBR | <<locked>> | 82% | 55,477 psi | 87% | 3077 fps | 100% |
| Lovex D073.6 | <<locked>> | 84% | 57,290 psi | 90% | 3110 fps | 100% |
| Lovex S060 | <<locked>> | 84% | 55,782 psi | 87% | 3054 fps | 100% |
| Lovex S062 | <<locked>> | 88% | 57,580 psi | 90% | 3117 fps | 100% |
| Lovex S065 | <<locked>> | 94% | 56,884 psi | 89% | 3117 fps | 99% |
| Lovex S070 | <<locked>> | 94% | 54,810 psi | 86% | 3104 fps | 97.9% |
| Norma 201 | <<locked>> | 84% | 56,130 psi | 88% | 3084 fps | 100% |
| Norma 202 | <<locked>> | 84% | 56,347 psi | 88% | 3077 fps | 100% |
| Norma 203B | <<locked>> | 86% | 54,665 psi | 86% | 3117 fps | 99.9% |
| Norma 204 | <<locked>> | 96% | 56,115 psi | 88% | 3163 fps | 96.1% |
| Norma MRPᴾ | <<locked>> | 100% | 50,792 psi | 80% | 3176 fps | 96.9% |
| Norma URP | <<locked>> | 96% | 56,289 psi | 88% | 3186 fps | 99.6% |
| Ramshot Big Game | <<locked>> | 86% | 54,998 psi | 86% | 3136 fps | 99.9% |
| Ramshot Hunter | <<locked>> | 96% | 54,708 psi | 86% | 3173 fps | 98.5% |
| Ramshot TAC | <<locked>> | 82% | 55,753 psi | 87% | 3097 fps | 99% |
| Ramshot Wild Boar | <<locked>> | 82% | 55,506 psi | 87% | 3117 fps | 99.9% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 36,796 psi | 58% | 1991 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 88% | 56,159 psi | 88% | 3110 fps | 98.4% |
| ReloadSwiss RS 52 | <<locked>> | 84% | 55,753 psi | 87% | 3199 fps | 99.8% |
| ReloadSwiss RS 60 | <<locked>> | 90% | 55,158 psi | 86% | 3232 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 96% | 57,276 psi | 90% | 3222 fps | 99.6% |
| ReloadSwiss RS 70 | <<locked>> | 96% | 55,854 psi | 88% | 3241 fps | 99.4% |
| Rottweil R 901 | <<locked>> | 82% | 57,435 psi | 90% | 3068 fps | 100% |
| Rottweil R 902 | <<locked>> | 86% | 56,594 psi | 89% | 3081 fps | 100% |
| Rottweil R 903 | <<locked>> | 90% | 55,883 psi | 88% | 3117 fps | 100% |
| Rottweil R 905ᴾ | <<locked>> | 100% | 53,156 psi | 83% | 3136 fps | 96% |
| Rottweil R 907 | <<locked>> | 92% | 55,448 psi | 87% | 3091 fps | 97.2% |
| Shooters World Long Rifle | <<locked>> | 94% | 56,884 psi | 89% | 3117 fps | 99% |
| Shooters World Match Rifle | <<locked>> | 84% | 57,290 psi | 90% | 3110 fps | 100% |
| Shooters World Precision | <<locked>> | 88% | 57,580 psi | 90% | 3117 fps | 100% |
| Shooters World SW4350 | <<locked>> | 94% | 54,810 psi | 86% | 3104 fps | 97.9% |
| SNPE Vectan SP 11 | <<locked>> | 90% | 57,072 psi | 89% | 3179 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 82% | 54,810 psi | 86% | 3077 fps | 99.2% |
| SNPE Vectan SP 9 | <<locked>> | 84% | 55,042 psi | 86% | 3100 fps | 99.9% |
| SNPE Vectan Tubal 3000 | <<locked>> | 84% | 56,420 psi | 88% | 3005 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 90% | 57,116 psi | 90% | 3005 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 94% | 56,884 psi | 89% | 3061 fps | 98% |
| SNPE Vectan Tubal 8000ᴾ | <<locked>> | 100% | 52,649 psi | 83% | 3130 fps | 95.8% |
| Somchem S335 | <<locked>> | 84% | 56,565 psi | 89% | 3009 fps | 100% |
| Somchem S341 | <<locked>> | 84% | 57,435 psi | 90% | 3117 fps | 100% |
| Somchem S355 | <<locked>> | 90% | 55,970 psi | 88% | 3114 fps | 100% |
| Somchem S365 | <<locked>> | 98% | 54,694 psi | 86% | 3189 fps | 100% |
| Somchem S385ᴾ | <<locked>> | 100% | 54,114 psi | 85% | 3117 fps | 97% |
| Vihtavuori N133 | <<locked>> | 84% | 56,681 psi | 89% | 2986 fps | 100% |
| Vihtavuori N135 | <<locked>> | 86% | 56,391 psi | 88% | 3041 fps | 100% |
| Vihtavuori N140 | <<locked>> | 86% | 56,797 psi | 89% | 3054 fps | 100% |
| Vihtavuori N150 | <<locked>> | 92% | 57,087 psi | 89% | 3087 fps | 100% |
| Vihtavuori N160 | <<locked>> | 94% | 54,723 psi | 86% | 3117 fps | 99.5% |
| Vihtavuori N530 | <<locked>> | 82% | 55,985 psi | 88% | 3077 fps | 100% |
| Vihtavuori N540 | <<locked>> | 86% | 54,955 psi | 86% | 3048 fps | 100% |
| Vihtavuori N550 | <<locked>> | 94% | 54,433 psi | 85% | 3130 fps | 99.3% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 50,792 psi | 80% | 3130 fps | 99.5% |
| Winchester 6.5 StaBALL | <<locked>> | 94% | 54,607 psi | 86% | 3087 fps | 100% |
| Winchester 748 | <<locked>> | 82% | 56,188 psi | 88% | 3130 fps | 100% |
| Winchester 760 | <<locked>> | 94% | 56,362 psi | 88% | 3192 fps | 98% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 41,234 psi | 65% | 3071 fps | 99.8% |
| Winchester StaBALL Match | <<locked>> | 84% | 55,056 psi | 86% | 3107 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 2495 | <<locked>> | 80% | 48,733 psi | 76% | 2920 fps | 100% |
| Accurate 2700 | <<locked>> | 82% | 48,950 psi | 77% | 2930 fps | 95.6% |
| Accurate 3100 | <<locked>> | 94% | 39,958 psi | 63% | 2841 fps | 95.1% |
| Accurate 4064 | <<locked>> | 80% | 46,021 psi | 72% | 2917 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 34,606 psi | 54% | 2736 fps | 95.2% |
| ADI AR 2206H | <<locked>> | 80% | 50,357 psi | 79% | 3022 fps | 99.7% |
| ADI AR 2208 | <<locked>> | 80% | 43,004 psi | 67% | 2864 fps | 98.2% |
| ADI AR 2209 | <<locked>> | 98% | 51,634 psi | 81% | 3104 fps | 95.1% |
| ADI Benchmark 8208 | <<locked>> | 80% | 52,214 psi | 82% | 3025 fps | 100% |
| Alliant AR-Comp | <<locked>> | 80% | 53,359 psi | 84% | 3005 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 46,108 psi | 72% | 3064 fps | 98.8% |
| Alliant Power Pro Varmint | <<locked>> | 98% | 51,416 psi | 81% | 3100 fps | 95.3% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 43,221 psi | 68% | 2894 fps | 99.4% |
| Alliant Reloder-15 | <<locked>> | 80% | 46,108 psi | 72% | 2959 fps | 98.9% |
| Alliant Reloder-16 | <<locked>> | 82% | 35,781 psi | 56% | 2789 fps | 95.8% |
| Alliant Reloder-17 | 37.4 gr | 80% | 37,608 psi | 59% | 2867 fps | 98.2% |
| Alliant Reloder-19 | <<locked>> | 98% | 50,749 psi | 80% | 3091 fps | 95.2% |
| Alliant Reloder-23 | <<locked>> | 88% | 31,923 psi | 50% | 2703 fps | 95.9% |
| Alliant Reloder-26 | <<locked>> | 90% | 36,767 psi | 58% | 2897 fps | 95.3% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 49,559 psi | 78% | 3025 fps | 99% |
| Bofors RP3 | <<locked>> | 80% | 43,685 psi | 68% | 2907 fps | 99.5% |
| Bofors RP7 | <<locked>> | 86% | 46,499 psi | 73% | 2923 fps | 95.2% |
| Hodgdon Benchmark | <<locked>> | 80% | 53,766 psi | 84% | 3009 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 80% | 51,895 psi | 81% | 3054 fps | 100% |
| Hodgdon H380 | <<locked>> | 80% | 44,048 psi | 69% | 2907 fps | 97.5% |
| Hodgdon H414 | <<locked>> | 86% | 43,627 psi | 68% | 2949 fps | 95.1% |
| Hodgdon H4350 | <<locked>> | 88% | 49,806 psi | 78% | 3028 fps | 95.3% |
| Hodgdon H4895 | <<locked>> | 80% | 50,836 psi | 80% | 3035 fps | 99.9% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 31,459 psi | 49% | 2631 fps | 95.9% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 47,050 psi | 74% | 3009 fps | 99.8% |
| Hodgdon Superformance | <<locked>> | 88% | 45,876 psi | 72% | 3022 fps | 95.2% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,093 psi | 42% | 1742 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 48,544 psi | 76% | 2979 fps | 99.7% |
| IMR 3031 | <<locked>> | 80% | 50,966 psi | 80% | 3025 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 45,208 psi | 71% | 2900 fps | 98.8% |
| IMR 4166 Enduron | <<locked>> | 80% | 47,181 psi | 74% | 2913 fps | 96% |
| IMR 4350 | <<locked>> | 90% | 46,340 psi | 73% | 2943 fps | 95.2% |
| IMR 4451 Enduron | <<locked>> | 84% | 44,759 psi | 70% | 2890 fps | 95.2% |
| IMR 4831 | <<locked>> | 82% | 35,505 psi | 56% | 2746 fps | 95.6% |
| IMR 4895 | <<locked>> | 80% | 47,239 psi | 74% | 2992 fps | 99.4% |
| IMR 8208 XBR | <<locked>> | 80% | 52,214 psi | 82% | 3025 fps | 100% |
| Lovex D073.6 | <<locked>> | 80% | 50,589 psi | 79% | 3009 fps | 100% |
| Lovex S060 | <<locked>> | 80% | 49,472 psi | 78% | 2943 fps | 99.6% |
| Lovex S062 | <<locked>> | 80% | 45,426 psi | 71% | 2907 fps | 99.8% |
| Lovex S065 | <<locked>> | 82% | 40,205 psi | 63% | 2795 fps | 95.6% |
| Lovex S070 | <<locked>> | 86% | 43,366 psi | 68% | 2884 fps | 95.3% |
| Norma 201 | <<locked>> | 80% | 49,661 psi | 78% | 2976 fps | 100% |
| Norma 202 | <<locked>> | 80% | 49,821 psi | 78% | 2976 fps | 100% |
| Norma 203B | <<locked>> | 80% | 45,513 psi | 71% | 2946 fps | 99.2% |
| Norma 204 | <<locked>> | 94% | 52,678 psi | 83% | 3104 fps | 95.4% |
| Norma MRP | <<locked>> | 96% | 44,483 psi | 70% | 3045 fps | 95.1% |
| Norma URP | <<locked>> | 82% | 36,463 psi | 57% | 2785 fps | 95.8% |
| Ramshot Big Game | <<locked>> | 80% | 45,063 psi | 71% | 2956 fps | 99% |
| Ramshot Hunter | <<locked>> | 86% | 39,987 psi | 63% | 2877 fps | 95% |
| Ramshot TAC | <<locked>> | 80% | 52,214 psi | 82% | 3035 fps | 98.5% |
| Ramshot Wild Boar | <<locked>> | 80% | 51,924 psi | 81% | 3054 fps | 99.8% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,760 psi | 44% | 1788 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 43,830 psi | 69% | 2877 fps | 95.8% |
| ReloadSwiss RS 52 | <<locked>> | 80% | 49,023 psi | 77% | 3081 fps | 99.3% |
| ReloadSwiss RS 60 | 37.4 gr | 80% | 39,798 psi | 62% | 2933 fps | 99.9% |
| ReloadSwiss RS 62 | <<locked>> | 82% | 36,085 psi | 57% | 2802 fps | 95.4% |
| ReloadSwiss RS 70 | 39.9 gr | 84% | 37,869 psi | 59% | 2858 fps | 95.2% |
| Rottweil R 901 | <<locked>> | 80% | 54,099 psi | 85% | 3015 fps | 100% |
| Rottweil R 902 | <<locked>> | 80% | 47,442 psi | 74% | 2923 fps | 99.9% |
| Rottweil R 903 | <<locked>> | 80% | 41,205 psi | 65% | 2848 fps | 98.9% |
| Rottweil R 905 | <<locked>> | 98% | 49,792 psi | 78% | 3074 fps | 95.1% |
| Rottweil R 907 | <<locked>> | 86% | 46,499 psi | 73% | 2923 fps | 95.2% |
| Shooters World Long Rifle | <<locked>> | 82% | 40,205 psi | 63% | 2795 fps | 95.6% |
| Shooters World Match Rifle | <<locked>> | 80% | 50,589 psi | 79% | 3009 fps | 100% |
| Shooters World Precision | <<locked>> | 80% | 45,426 psi | 71% | 2907 fps | 99.8% |
| Shooters World SW4350 | <<locked>> | 86% | 43,366 psi | 68% | 2884 fps | 95.3% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 41,655 psi | 65% | 2894 fps | 98.5% |
| SNPE Vectan SP 7 | <<locked>> | 80% | 51,198 psi | 80% | 3015 fps | 98.7% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 48,849 psi | 77% | 2992 fps | 99.5% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 50,502 psi | 79% | 2910 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 42,612 psi | 67% | 2769 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 86% | 44,744 psi | 70% | 2844 fps | 95.4% |
| SNPE Vectan Tubal 8000 | <<locked>> | 98% | 49,414 psi | 77% | 3071 fps | 95% |
| Somchem S335 | <<locked>> | 80% | 50,169 psi | 79% | 2910 fps | 100% |
| Somchem S341 | <<locked>> | 80% | 50,531 psi | 79% | 3005 fps | 99.6% |
| Somchem S355 | <<locked>> | 80% | 41,524 psi | 65% | 2844 fps | 98.8% |
| Somchem S365 | <<locked>> | 80% | 31,067 psi | 49% | 2684 fps | 97.4% |
| Somchem S385 | <<locked>> | 96% | 47,819 psi | 75% | 3002 fps | 95.6% |
| Vihtavuori N133 | <<locked>> | 80% | 50,705 psi | 79% | 2897 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 47,224 psi | 74% | 2897 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 47,210 psi | 74% | 2900 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 39,537 psi | 62% | 2776 fps | 99.4% |
| Vihtavuori N160 | <<locked>> | 80% | 35,534 psi | 56% | 2726 fps | 95.3% |
| Vihtavuori N530 | <<locked>> | 80% | 52,620 psi | 82% | 3025 fps | 100% |
| Vihtavuori N540 | <<locked>> | 80% | 45,876 psi | 72% | 2894 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 35,273 psi | 55% | 2730 fps | 95% |
| Vihtavuori N555 | <<locked>> | 86% | 32,735 psi | 51% | 2733 fps | 95.2% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 34,998 psi | 55% | 2694 fps | 97.5% |
| Winchester 748 | <<locked>> | 80% | 52,823 psi | 83% | 3074 fps | 100% |
| Winchester 760 | <<locked>> | 86% | 43,627 psi | 68% | 2949 fps | 95.1% |
| Winchester StaBALL HD | <<locked>> | 90% | 30,487 psi | 48% | 2736 fps | 95.8% |
| Winchester StaBALL Match | <<locked>> | 80% | 48,443 psi | 76% | 2992 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 97 powders for .243 WSSM loaded with the .243 | 90gr | Impala RNFP KO. Alliant Power Pro 2000-MR delivers the highest muzzle velocity at 3,261 fps; across all powders the maximum-charge window runs from 1,946 fps to 3,261 fps. Accurate 3100 gives the best case fill at 100 %, and 97 of the 97 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (440 MPa), the top charges use 57–90 %, leaving at least 10 % headroom. The 90.0 gr projectile in 0.243" calls for a 1:8.5 twist; slower twists will usually not stabilise this weight. Accurate 3100, ADI AR 2209, Alliant Power Pro Varmint 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, ReloadSwiss RS 60 rank at the top here: for .243 WSSM with the .243 | 90gr | Impala RNFP KO 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.