Load Specifications
Load data in caliber .243 WSSM with .243 | 90gr | Berger BT M T bullet and 96 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are ReloadSwiss RS 70, Hodgdon Superformance and Alliant Reloder-17.
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.
A valid access license is required to use the Personalized Load Calculator.
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 2015 | <<locked>> | 82% | 54,998 psi | 86% | 3009 fps | 100% |
| Accurate 2495 | <<locked>> | 86% | 54,331 psi | 85% | 3035 fps | 100% |
| Accurate 2520 | <<locked>> | 82% | 55,550 psi | 87% | 3100 fps | 100% |
| Accurate 2700 | <<locked>> | 88% | 56,666 psi | 89% | 3087 fps | 97.3% |
| Accurate 3100ᴾ | <<locked>> | 100% | 45,281 psi | 71% | 2979 fps | 96.8% |
| Accurate 4064 | <<locked>> | 88% | 54,549 psi | 85% | 3087 fps | 100% |
| Accurate 4350 | <<locked>> | 96% | 54,810 psi | 86% | 3176 fps | 99.6% |
| ADI AR 2206H | <<locked>> | 86% | 57,653 psi | 90% | 3169 fps | 100% |
| ADI AR 2208 | <<locked>> | 90% | 55,187 psi | 86% | 3110 fps | 99.8% |
| ADI Benchmark 8208 | <<locked>> | 84% | 56,492 psi | 89% | 3114 fps | 100% |
| Alliant AR-Comp | <<locked>> | 82% | 54,186 psi | 85% | 3038 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 86% | 54,215 psi | 85% | 3241 fps | 99.8% |
| Alliant Reloder- TS 15.5 | <<locked>> | 90% | 55,753 psi | 87% | 3140 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 88% | 55,985 psi | 88% | 3163 fps | 99.9% |
| Alliant Reloder-16 | <<locked>> | 98% | 55,506 psi | 87% | 3235 fps | 99.9% |
| Alliant Reloder-17 | <<locked>> | 94% | 56,913 psi | 89% | 3271 fps | 100% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 42,743 psi | 67% | 3005 fps | 99.3% |
| Alliant Reloder-26ᴾ | <<locked>> | 100% | 48,515 psi | 76% | 3196 fps | 98.9% |
| Baschieri & Pellagri 107 | <<locked>> | 84% | 54,085 psi | 85% | 3123 fps | 99.6% |
| Bofors RP3 | <<locked>> | 90% | 56,565 psi | 89% | 3159 fps | 100% |
| Bofors RP7 | <<locked>> | 94% | 56,420 psi | 88% | 3127 fps | 97.5% |
| Hodgdon Benchmark | <<locked>> | 82% | 54,824 psi | 86% | 3048 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 84% | 56,347 psi | 88% | 3146 fps | 100% |
| Hodgdon H380 | <<locked>> | 90% | 57,188 psi | 90% | 3169 fps | 99.5% |
| Hodgdon H414 | <<locked>> | 96% | 57,348 psi | 90% | 3228 fps | 98.3% |
| Hodgdon H4350 | <<locked>> | 94% | 57,522 psi | 90% | 3186 fps | 97.1% |
| Hodgdon H4895 | <<locked>> | 84% | 54,752 psi | 86% | 3123 fps | 100% |
| Hodgdon Hybrid 100Vᴾ | <<locked>> | 100% | 55,593 psi | 87% | 3156 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 86% | 54,723 psi | 86% | 3163 fps | 100% |
| Hodgdon Superformance | <<locked>> | 94% | 54,143 psi | 85% | 3202 fps | 97.5% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 35,882 psi | 56% | 1955 fps | 100% |
| Hodgdon VARGET | <<locked>> | 86% | 55,941 psi | 88% | 3127 fps | 100% |
| IMR 3031 | <<locked>> | 84% | 54,853 psi | 86% | 3107 fps | 100% |
| IMR 4064 | <<locked>> | 88% | 54,984 psi | 86% | 3100 fps | 99.9% |
| IMR 4166 Enduron | <<locked>> | 86% | 54,505 psi | 85% | 3074 fps | 97.7% |
| IMR 4350 | <<locked>> | 98% | 56,695 psi | 89% | 3153 fps | 97.7% |
| IMR 4451 Enduron | <<locked>> | 92% | 54,447 psi | 85% | 3100 fps | 97.6% |
| IMR 4831 | <<locked>> | 98% | 55,187 psi | 86% | 3163 fps | 99.7% |
| IMR 4895 | <<locked>> | 88% | 57,450 psi | 90% | 3196 fps | 100% |
| IMR 8208 XBR | <<locked>> | 84% | 56,492 psi | 89% | 3114 fps | 100% |
| Lovex D073.6 | <<locked>> | 84% | 54,302 psi | 85% | 3091 fps | 100% |
| Lovex S060 | <<locked>> | 86% | 57,029 psi | 89% | 3094 fps | 100% |
| Lovex S062 | <<locked>> | 88% | 54,984 psi | 86% | 3097 fps | 100% |
| Lovex S065 | <<locked>> | 96% | 57,638 psi | 90% | 3153 fps | 99.1% |
| Lovex S070 | <<locked>> | 96% | 55,347 psi | 87% | 3133 fps | 98.1% |
| Norma 201 | <<locked>> | 86% | 56,507 psi | 89% | 3114 fps | 100% |
| Norma 202 | <<locked>> | 86% | 57,101 psi | 89% | 3114 fps | 100% |
| Norma 203B | <<locked>> | 88% | 55,201 psi | 87% | 3146 fps | 100% |
| Norma 204 | <<locked>> | 98% | 57,725 psi | 90% | 3209 fps | 96.6% |
| Norma MRPᴾ | <<locked>> | 100% | 47,834 psi | 75% | 3136 fps | 96.3% |
| Norma URP | <<locked>> | 98% | 57,188 psi | 90% | 3219 fps | 99.7% |
| Ramshot Big Game | <<locked>> | 88% | 55,999 psi | 88% | 3173 fps | 100% |
| Ramshot Hunter | <<locked>> | 98% | 55,912 psi | 88% | 3212 fps | 98.8% |
| Ramshot TAC | <<locked>> | 84% | 56,927 psi | 89% | 3136 fps | 99.2% |
| Ramshot Wild Boar | <<locked>> | 84% | 56,637 psi | 89% | 3156 fps | 100% |
| Ramshot X-Terminator | <<locked>> | 82% | 57,305 psi | 90% | 3117 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 36,114 psi | 57% | 1995 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 90% | 57,508 psi | 90% | 3153 fps | 98.7% |
| ReloadSwiss RS 52 | <<locked>> | 86% | 56,855 psi | 89% | 3238 fps | 99.9% |
| ReloadSwiss RS 60 | <<locked>> | 92% | 56,710 psi | 89% | 3274 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 96% | 54,230 psi | 85% | 3192 fps | 99.4% |
| ReloadSwiss RS 70 | <<locked>> | 98% | 57,667 psi | 90% | 3291 fps | 99.7% |
| Rottweil R 901 | <<locked>> | 84% | 57,159 psi | 90% | 3091 fps | 100% |
| Rottweil R 902 | <<locked>> | 88% | 56,971 psi | 89% | 3110 fps | 100% |
| Rottweil R 903 | <<locked>> | 92% | 56,391 psi | 88% | 3150 fps | 100% |
| Rottweil R 907 | <<locked>> | 94% | 56,420 psi | 88% | 3127 fps | 97.5% |
| Shooters World Long Rifle | <<locked>> | 96% | 57,638 psi | 90% | 3153 fps | 99.1% |
| Shooters World Match Rifle | <<locked>> | 84% | 54,302 psi | 85% | 3091 fps | 100% |
| Shooters World Precision | <<locked>> | 88% | 54,984 psi | 86% | 3097 fps | 100% |
| Shooters World SW4350 | <<locked>> | 96% | 55,347 psi | 87% | 3133 fps | 98.1% |
| SNPE Vectan SP 11 | <<locked>> | 90% | 54,578 psi | 86% | 3156 fps | 99.9% |
| SNPE Vectan SP 7 | <<locked>> | 84% | 55,550 psi | 87% | 3114 fps | 99.3% |
| SNPE Vectan SP 9 | <<locked>> | 86% | 56,246 psi | 88% | 3140 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 86% | 57,653 psi | 90% | 3041 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 90% | 54,636 psi | 86% | 2989 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 94% | 54,201 psi | 85% | 3038 fps | 97.7% |
| Somchem S335 | <<locked>> | 86% | 57,217 psi | 90% | 3041 fps | 100% |
| Somchem S341 | <<locked>> | 84% | 55,056 psi | 86% | 3100 fps | 99.9% |
| Somchem S355 | <<locked>> | 92% | 56,318 psi | 88% | 3143 fps | 100% |
| Somchem S365ᴾ | <<locked>> | 100% | 55,434 psi | 87% | 3219 fps | 100% |
| Somchem S385ᴾ | <<locked>> | 100% | 51,488 psi | 81% | 3091 fps | 96.6% |
| Vihtavuori N130 | <<locked>> | 82% | 57,188 psi | 90% | 2999 fps | 100% |
| Vihtavuori N133 | <<locked>> | 84% | 54,766 psi | 86% | 2982 fps | 100% |
| Vihtavuori N135 | <<locked>> | 88% | 57,058 psi | 89% | 3071 fps | 100% |
| Vihtavuori N140 | <<locked>> | 88% | 57,653 psi | 90% | 3084 fps | 100% |
| Vihtavuori N150 | <<locked>> | 92% | 54,491 psi | 85% | 3068 fps | 100% |
| Vihtavuori N160 | <<locked>> | 96% | 56,101 psi | 88% | 3159 fps | 99.6% |
| Vihtavuori N530 | <<locked>> | 84% | 56,985 psi | 89% | 3114 fps | 100% |
| Vihtavuori N540 | <<locked>> | 88% | 55,898 psi | 88% | 3081 fps | 100% |
| Vihtavuori N550 | <<locked>> | 96% | 55,042 psi | 86% | 3159 fps | 99.5% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 47,427 psi | 74% | 3091 fps | 99.2% |
| Winchester 6.5 StaBALL | <<locked>> | 96% | 56,275 psi | 88% | 3130 fps | 100% |
| Winchester 748 | <<locked>> | 84% | 57,464 psi | 90% | 3169 fps | 100% |
| Winchester 760 | <<locked>> | 96% | 57,348 psi | 90% | 3228 fps | 98.3% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 38,247 psi | 60% | 3015 fps | 99.4% |
| Winchester StaBALL Match | <<locked>> | 86% | 56,115 psi | 88% | 3143 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 2015 | <<locked>> | 80% | 51,517 psi | 81% | 2956 fps | 100% |
| Accurate 2495 | <<locked>> | 80% | 44,512 psi | 70% | 2877 fps | 100% |
| Accurate 2520 | <<locked>> | 80% | 52,069 psi | 82% | 3045 fps | 100% |
| Accurate 2700 | <<locked>> | 82% | 46,282 psi | 73% | 2900 fps | 95% |
| Accurate 3100 | <<locked>> | 96% | 39,392 psi | 62% | 2854 fps | 95.1% |
| Accurate 4064 | <<locked>> | 80% | 42,061 psi | 66% | 2871 fps | 100% |
| Accurate 4350 | <<locked>> | 84% | 35,853 psi | 56% | 2799 fps | 95.8% |
| ADI AR 2206H | <<locked>> | 80% | 47,732 psi | 75% | 2995 fps | 99.5% |
| ADI AR 2208 | <<locked>> | 80% | 40,741 psi | 64% | 2835 fps | 97.8% |
| ADI Benchmark 8208 | <<locked>> | 80% | 49,792 psi | 78% | 3005 fps | 100% |
| Alliant AR-Comp | <<locked>> | 80% | 50,618 psi | 79% | 2986 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 43,918 psi | 69% | 3038 fps | 98.5% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 40,437 psi | 63% | 2858 fps | 99% |
| Alliant Reloder-15 | <<locked>> | 80% | 43,381 psi | 68% | 2927 fps | 98.5% |
| Alliant Reloder-16 | <<locked>> | 84% | 35,563 psi | 56% | 2808 fps | 95.8% |
| Alliant Reloder-17 | 38 gr | 80% | 35,157 psi | 55% | 2825 fps | 97.5% |
| Alliant Reloder-23 | <<locked>> | 90% | 31,227 psi | 49% | 2710 fps | 95.7% |
| Alliant Reloder-26 | <<locked>> | 92% | 36,347 psi | 57% | 2907 fps | 95.3% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 47,355 psi | 74% | 3005 fps | 98.8% |
| Bofors RP3 | <<locked>> | 80% | 40,393 psi | 63% | 2864 fps | 99.1% |
| Bofors RP7 | <<locked>> | 88% | 46,586 psi | 73% | 2949 fps | 95.4% |
| Hodgdon Benchmark | <<locked>> | 80% | 51,488 psi | 81% | 2992 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 80% | 49,284 psi | 77% | 3031 fps | 100% |
| Hodgdon H380 | <<locked>> | 80% | 41,104 psi | 64% | 2867 fps | 96.9% |
| Hodgdon H414 | <<locked>> | 88% | 43,932 psi | 69% | 2979 fps | 95.4% |
| Hodgdon H4350 | <<locked>> | 90% | 50,676 psi | 79% | 3068 fps | 95.7% |
| Hodgdon H4895 | <<locked>> | 80% | 48,240 psi | 76% | 3012 fps | 99.7% |
| Hodgdon Hybrid 100V | <<locked>> | 82% | 30,806 psi | 48% | 2641 fps | 95.8% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 44,411 psi | 70% | 2976 fps | 99.6% |
| Hodgdon Superformance | 45.2 gr | 90% | 46,876 psi | 73% | 3064 fps | 95.7% |
| Hodgdon TrailBoss | <<locked>> | 80% | 26,614 psi | 42% | 1745 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 46,224 psi | 72% | 2959 fps | 99.5% |
| IMR 3031 | <<locked>> | 80% | 48,254 psi | 76% | 3002 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 42,801 psi | 67% | 2874 fps | 98.5% |
| IMR 4166 Enduron | <<locked>> | 80% | 45,165 psi | 71% | 2897 fps | 95.6% |
| IMR 4350 | <<locked>> | 92% | 46,934 psi | 74% | 2976 fps | 95.5% |
| IMR 4451 Enduron | <<locked>> | 86% | 45,469 psi | 71% | 2930 fps | 95.6% |
| IMR 4831 | <<locked>> | 84% | 34,766 psi | 54% | 2753 fps | 95.5% |
| IMR 4895 | <<locked>> | 80% | 44,483 psi | 70% | 2963 fps | 99.1% |
| IMR 8208 XBR | <<locked>> | 80% | 49,792 psi | 78% | 3005 fps | 100% |
| Lovex D073.6 | <<locked>> | 80% | 47,326 psi | 74% | 2976 fps | 100% |
| Lovex S060 | <<locked>> | 80% | 47,326 psi | 74% | 2927 fps | 99.4% |
| Lovex S062 | <<locked>> | 80% | 42,583 psi | 67% | 2874 fps | 99.5% |
| Lovex S065 | <<locked>> | 84% | 39,798 psi | 62% | 2812 fps | 95.6% |
| Lovex S070 | <<locked>> | 88% | 42,989 psi | 67% | 2900 fps | 95.3% |
| Norma 201 | <<locked>> | 80% | 46,673 psi | 73% | 2946 fps | 99.9% |
| Norma 202 | <<locked>> | 80% | 47,123 psi | 74% | 2949 fps | 100% |
| Norma 203B | <<locked>> | 80% | 42,772 psi | 67% | 2917 fps | 98.8% |
| Norma 204 | <<locked>> | 96% | 54,041 psi | 85% | 3146 fps | 95.8% |
| Norma MRP | <<locked>> | 98% | 44,773 psi | 70% | 3074 fps | 95.4% |
| Norma URP | <<locked>> | 84% | 35,969 psi | 56% | 2799 fps | 95.7% |
| Ramshot Big Game | <<locked>> | 80% | 42,714 psi | 67% | 2933 fps | 98.7% |
| Ramshot Hunter | <<locked>> | 88% | 40,016 psi | 63% | 2897 fps | 95.1% |
| Ramshot TAC | <<locked>> | 80% | 49,748 psi | 78% | 3012 fps | 98.2% |
| Ramshot Wild Boar | <<locked>> | 80% | 49,632 psi | 78% | 3035 fps | 99.6% |
| Ramshot X-Terminator | <<locked>> | 80% | 53,896 psi | 84% | 3061 fps | 99.9% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 26,890 psi | 42% | 1785 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 41,466 psi | 65% | 2848 fps | 95.2% |
| ReloadSwiss RS 52 | <<locked>> | 80% | 46,195 psi | 72% | 3048 fps | 98.9% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 37,420 psi | 59% | 2900 fps | 99.7% |
| ReloadSwiss RS 62 | <<locked>> | 84% | 35,520 psi | 56% | 2808 fps | 95.3% |
| ReloadSwiss RS 70 | 41.5 gr | 86% | 38,043 psi | 60% | 2884 fps | 95.4% |
| Rottweil R 901 | <<locked>> | 80% | 50,778 psi | 80% | 2989 fps | 100% |
| Rottweil R 902 | <<locked>> | 80% | 44,469 psi | 70% | 2890 fps | 99.7% |
| Rottweil R 903 | <<locked>> | 80% | 37,942 psi | 59% | 2802 fps | 98.4% |
| Rottweil R 907 | <<locked>> | 88% | 46,586 psi | 73% | 2949 fps | 95.4% |
| Shooters World Long Rifle | <<locked>> | 84% | 39,798 psi | 62% | 2812 fps | 95.6% |
| Shooters World Match Rifle | <<locked>> | 80% | 47,326 psi | 74% | 2976 fps | 100% |
| Shooters World Precision | <<locked>> | 80% | 42,583 psi | 67% | 2874 fps | 99.5% |
| Shooters World SW4350 | <<locked>> | 88% | 42,989 psi | 67% | 2900 fps | 95.3% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 39,001 psi | 61% | 2858 fps | 97.9% |
| SNPE Vectan SP 7 | <<locked>> | 80% | 48,559 psi | 76% | 2992 fps | 98.4% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 46,282 psi | 73% | 2963 fps | 99.3% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 47,747 psi | 75% | 2890 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 39,929 psi | 63% | 2743 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 88% | 44,628 psi | 70% | 2867 fps | 95.6% |
| Somchem S335 | <<locked>> | 80% | 47,514 psi | 74% | 2887 fps | 100% |
| Somchem S341 | <<locked>> | 80% | 48,182 psi | 76% | 2986 fps | 99.5% |
| Somchem S355 | <<locked>> | 80% | 38,580 psi | 60% | 2805 fps | 98.3% |
| Somchem S365 | <<locked>> | 80% | 28,224 psi | 44% | 2618 fps | 96.1% |
| Somchem S385 | <<locked>> | 98% | 47,848 psi | 75% | 3025 fps | 95.8% |
| Vihtavuori N130 | <<locked>> | 80% | 53,693 psi | 84% | 2949 fps | 100% |
| Vihtavuori N133 | <<locked>> | 80% | 48,138 psi | 75% | 2881 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 44,077 psi | 69% | 2867 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 44,672 psi | 70% | 2877 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 36,767 psi | 58% | 2736 fps | 99% |
| Vihtavuori N160 | <<locked>> | 82% | 35,070 psi | 55% | 2740 fps | 95.3% |
| Vihtavuori N530 | <<locked>> | 80% | 50,067 psi | 78% | 3002 fps | 100% |
| Vihtavuori N540 | <<locked>> | 80% | 43,178 psi | 68% | 2867 fps | 100% |
| Vihtavuori N550 | <<locked>> | 84% | 37,173 psi | 58% | 2805 fps | 95.8% |
| Vihtavuori N555 | <<locked>> | 90% | 33,765 psi | 53% | 2785 fps | 95.8% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 32,706 psi | 51% | 2657 fps | 96.8% |
| Winchester 748 | <<locked>> | 80% | 50,169 psi | 79% | 3051 fps | 100% |
| Winchester 760 | <<locked>> | 88% | 43,932 psi | 69% | 2979 fps | 95.4% |
| Winchester StaBALL HD | <<locked>> | 92% | 29,472 psi | 46% | 2726 fps | 95.2% |
| Winchester StaBALL Match | <<locked>> | 80% | 46,050 psi | 72% | 2969 fps | 99.6% |
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 96 powders for .243 WSSM loaded with the .243 | 90gr | Berger BT M T. ReloadSwiss RS 70 delivers the highest muzzle velocity at 3,291 fps; across all powders the maximum-charge window runs from 1,955 fps to 3,291 fps. Accurate 3100 gives the best case fill at 100 %, and 96 of the 96 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (440 MPa), the top charges use 56–90 %, leaving at least 10 % headroom. The 90.0 gr projectile in 0.243" calls for a 1:9.0 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, Hodgdon Superformance, Alliant Reloder-17 rank at the top here: for .243 WSSM with the .243 | 90gr | Berger BT M T 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.