Load Specifications
Load data in caliber 6 mm GT with .243 | 88gr | Berger Varmint bullet and 95 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are ReloadSwiss RS 60, Alliant Power Pro 2000-MR and ReloadSwiss RS 52.
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>> | 86% | 53,461 psi | 86% | 2956 fps | 100% |
| Accurate 2460 | <<locked>> | 84% | 55,332 psi | 89% | 3028 fps | 100% |
| Accurate 2495 | <<locked>> | 92% | 54,810 psi | 88% | 3018 fps | 100% |
| Accurate 2520 | <<locked>> | 88% | 55,477 psi | 89% | 3077 fps | 100% |
| Accurate 4064 | <<locked>> | 94% | 54,723 psi | 88% | 3064 fps | 100% |
| Accurate 4350ᴾ | <<locked>> | 100% | 50,372 psi | 81% | 3068 fps | 98.1% |
| Accurate LT-30 | <<locked>> | 82% | 53,345 psi | 86% | 2877 fps | 100% |
| Accurate LT-32 | <<locked>> | 82% | 53,737 psi | 87% | 2900 fps | 100% |
| ADI AR 2206H | <<locked>> | 90% | 55,825 psi | 90% | 3097 fps | 99.5% |
| ADI AR 2208 | <<locked>> | 94% | 53,534 psi | 86% | 3038 fps | 98.9% |
| ADI Benchmark 8208 | <<locked>> | 88% | 54,897 psi | 89% | 3048 fps | 99.9% |
| Alliant AR-Comp | <<locked>> | 88% | 55,230 psi | 89% | 3031 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 92% | 55,796 psi | 90% | 3222 fps | 99.3% |
| Alliant Reloder- TS 15.5 | <<locked>> | 94% | 53,185 psi | 86% | 3064 fps | 99.7% |
| Alliant Reloder-10x | <<locked>> | 82% | 53,200 psi | 86% | 2963 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 92% | 53,795 psi | 87% | 3084 fps | 99.1% |
| Alliant Reloder-16ᴾ | <<locked>> | 100% | 49,298 psi | 80% | 3071 fps | 98.1% |
| Alliant Reloder-17 | <<locked>> | 98% | 53,621 psi | 86% | 3179 fps | 99.8% |
| Baschieri & Pellagri 106 | <<locked>> | 82% | 55,172 psi | 89% | 2936 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 90% | 55,912 psi | 90% | 3114 fps | 99% |
| Bofors RP3 | <<locked>> | 94% | 53,606 psi | 86% | 3077 fps | 99.8% |
| Hodgdon Benchmark | <<locked>> | 86% | 53,940 psi | 87% | 2989 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 88% | 54,331 psi | 88% | 3084 fps | 100% |
| Hodgdon CFE223 | <<locked>> | 84% | 52,127 psi | 84% | 3117 fps | 98.9% |
| Hodgdon H322 | <<locked>> | 84% | 56,014 psi | 90% | 3058 fps | 100% |
| Hodgdon H335 | <<locked>> | 82% | 53,330 psi | 86% | 3025 fps | 100% |
| Hodgdon H380 | <<locked>> | 94% | 54,969 psi | 89% | 3087 fps | 98.3% |
| Hodgdon H414ᴾ | <<locked>> | 100% | 54,114 psi | 87% | 3127 fps | 96.2% |
| Hodgdon H4895 | <<locked>> | 88% | 52,866 psi | 85% | 3051 fps | 99.6% |
| Hodgdon Hybrid 100Vᴾ | <<locked>> | 100% | 45,600 psi | 74% | 2949 fps | 98.7% |
| Hodgdon LEVERevolution | <<locked>> | 92% | 55,535 psi | 90% | 3143 fps | 99.9% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 35,099 psi | 57% | 1886 fps | 100% |
| Hodgdon VARGET | <<locked>> | 90% | 54,331 psi | 88% | 3058 fps | 99.6% |
| IMR 3031 | <<locked>> | 90% | 55,796 psi | 90% | 3097 fps | 100% |
| IMR 4064 | <<locked>> | 92% | 53,243 psi | 86% | 3025 fps | 99% |
| IMR 4166 Enduron | <<locked>> | 90% | 53,635 psi | 87% | 2999 fps | 95.9% |
| IMR 4198 | <<locked>> | 82% | 53,359 psi | 86% | 2923 fps | 100% |
| IMR 4831ᴾ | <<locked>> | 100% | 48,066 psi | 78% | 3005 fps | 97.7% |
| IMR 4895 | <<locked>> | 92% | 55,143 psi | 89% | 3120 fps | 99.5% |
| IMR 8208 XBR | <<locked>> | 88% | 54,897 psi | 89% | 3048 fps | 99.9% |
| Lovex D073.5 | <<locked>> | 84% | 55,492 psi | 90% | 3041 fps | 100% |
| Lovex D073.6 | <<locked>> | 90% | 55,477 psi | 89% | 3077 fps | 100% |
| Lovex S060 | <<locked>> | 90% | 55,985 psi | 90% | 3028 fps | 99.5% |
| Lovex S062 | <<locked>> | 94% | 56,043 psi | 90% | 3074 fps | 100% |
| Lovex S065ᴾ | <<locked>> | 100% | 55,201 psi | 89% | 3061 fps | 97.6% |
| Lovex S070ᴾ | <<locked>> | 100% | 52,475 psi | 85% | 3035 fps | 96% |
| Norma 201 | <<locked>> | 90% | 54,853 psi | 88% | 3045 fps | 99.9% |
| Norma 202 | <<locked>> | 90% | 55,376 psi | 89% | 3054 fps | 100% |
| Norma 203B | <<locked>> | 92% | 52,953 psi | 85% | 3071 fps | 99.3% |
| Norma URPᴾ | <<locked>> | 100% | 49,966 psi | 81% | 3058 fps | 97.9% |
| Ramshot Big Game | <<locked>> | 92% | 53,664 psi | 87% | 3097 fps | 99.3% |
| Ramshot Hunterᴾ | <<locked>> | 100% | 49,168 psi | 79% | 3045 fps | 96% |
| Ramshot TAC | <<locked>> | 88% | 55,550 psi | 90% | 3061 fps | 97.8% |
| Ramshot Wild Boar | <<locked>> | 88% | 54,969 psi | 89% | 3084 fps | 99.5% |
| Ramshot X-Terminator | <<locked>> | 84% | 52,881 psi | 85% | 2995 fps | 99.1% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 35,259 psi | 57% | 1926 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 84% | 54,621 psi | 88% | 3035 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 94% | 55,579 psi | 90% | 3068 fps | 97% |
| ReloadSwiss RS 52 | <<locked>> | 90% | 53,998 psi | 87% | 3153 fps | 99.1% |
| ReloadSwiss RS 60 | <<locked>> | 96% | 53,534 psi | 86% | 3189 fps | 100% |
| ReloadSwiss RS 62ᴾ | <<locked>> | 100% | 50,183 psi | 81% | 3087 fps | 97.8% |
| ReloadSwiss RS 70ᴾ | <<locked>> | 100% | 50,966 psi | 82% | 3114 fps | 97.4% |
| Rottweil R 901 | <<locked>> | 88% | 55,564 psi | 90% | 3028 fps | 100% |
| Rottweil R 902 | <<locked>> | 92% | 55,013 psi | 89% | 3038 fps | 99.9% |
| Rottweil R 903 | <<locked>> | 96% | 53,461 psi | 86% | 3068 fps | 99.7% |
| Shooters World Long Rifleᴾ | <<locked>> | 100% | 55,201 psi | 89% | 3061 fps | 97.6% |
| Shooters World Match Rifle | <<locked>> | 90% | 55,477 psi | 89% | 3077 fps | 100% |
| Shooters World Precision | <<locked>> | 94% | 56,043 psi | 90% | 3074 fps | 100% |
| Shooters World Tactical Rifle | <<locked>> | 82% | 54,505 psi | 88% | 3002 fps | 99.8% |
| SNPE Vectan SP 11 | <<locked>> | 96% | 55,259 psi | 89% | 3130 fps | 99.5% |
| SNPE Vectan SP 3 | <<locked>> | 84% | 54,520 psi | 88% | 2966 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 88% | 53,635 psi | 87% | 3035 fps | 98% |
| SNPE Vectan SP 9 | <<locked>> | 90% | 54,534 psi | 88% | 3068 fps | 99.4% |
| SNPE Vectan Tubal 3000 | <<locked>> | 88% | 53,330 psi | 86% | 2943 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 94% | 53,127 psi | 86% | 2933 fps | 100% |
| SNPE Vectan Tubal 7000ᴾ | <<locked>> | 100% | 55,854 psi | 90% | 3009 fps | 96.3% |
| Somchem S321 | <<locked>> | 84% | 52,953 psi | 85% | 3035 fps | 99.9% |
| Somchem S335 | <<locked>> | 90% | 55,912 psi | 90% | 2986 fps | 100% |
| Somchem S341 | <<locked>> | 88% | 53,548 psi | 86% | 3031 fps | 99.3% |
| Somchem S355 | <<locked>> | 96% | 54,041 psi | 87% | 3068 fps | 99.6% |
| Somchem S365ᴾ | <<locked>> | 100% | 44,541 psi | 72% | 3002 fps | 99.5% |
| Unknown powderᴾ | <<locked>> | 100% | 54,621 psi | 88% | 3127 fps | 98.1% |
| Vihtavuori N130 | <<locked>> | 84% | 53,026 psi | 86% | 2907 fps | 100% |
| Vihtavuori N133 | <<locked>> | 88% | 53,374 psi | 86% | 2930 fps | 100% |
| Vihtavuori N135 | <<locked>> | 94% | 54,027 psi | 87% | 2979 fps | 100% |
| Vihtavuori N140 | <<locked>> | 92% | 55,579 psi | 90% | 3025 fps | 100% |
| Vihtavuori N150 | <<locked>> | 98% | 55,259 psi | 89% | 3045 fps | 100% |
| Vihtavuori N160ᴾ | <<locked>> | 100% | 52,489 psi | 85% | 3058 fps | 98.2% |
| Vihtavuori N530 | <<locked>> | 88% | 55,651 psi | 90% | 3051 fps | 99.9% |
| Vihtavuori N540 | <<locked>> | 92% | 53,940 psi | 87% | 3022 fps | 100% |
| Vihtavuori N550ᴾ | <<locked>> | 100% | 51,837 psi | 84% | 3064 fps | 98% |
| Winchester 6.5 StaBALLᴾ | <<locked>> | 100% | 53,693 psi | 87% | 3045 fps | 99.7% |
| Winchester 748 | <<locked>> | 88% | 55,477 psi | 89% | 3104 fps | 100% |
| Winchester 760ᴾ | <<locked>> | 100% | 54,114 psi | 87% | 3127 fps | 96.2% |
| Winchester StaBALL Match | <<locked>> | 90% | 54,027 psi | 87% | 3071 fps | 99.7% |
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% | 44,498 psi | 72% | 2812 fps | 100% |
| Accurate 2460 | <<locked>> | 80% | 48,501 psi | 78% | 2920 fps | 100% |
| Accurate 2495 | <<locked>> | 80% | 36,811 psi | 59% | 2707 fps | 100% |
| Accurate 2520 | <<locked>> | 80% | 42,018 psi | 68% | 2844 fps | 99.6% |
| Accurate 4064 | <<locked>> | 80% | 34,780 psi | 56% | 2690 fps | 99.1% |
| Accurate 4350 | <<locked>> | 94% | 40,915 psi | 66% | 2884 fps | 95.9% |
| Accurate LT-30 | <<locked>> | 80% | 50,212 psi | 81% | 2828 fps | 100% |
| Accurate LT-32 | <<locked>> | 80% | 50,589 psi | 82% | 2851 fps | 100% |
| ADI AR 2206H | <<locked>> | 80% | 40,741 psi | 66% | 2812 fps | 97.1% |
| ADI AR 2208 | <<locked>> | 82% | 37,072 psi | 60% | 2710 fps | 95.2% |
| ADI Benchmark 8208 | <<locked>> | 80% | 42,743 psi | 69% | 2828 fps | 98.6% |
| Alliant AR-Comp | <<locked>> | 80% | 42,322 psi | 68% | 2835 fps | 100% |
| Alliant Power Pro 2000-MR | 34.1 gr | 82% | 39,479 psi | 64% | 2884 fps | 95.5% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 33,968 psi | 55% | 2667 fps | 96% |
| Alliant Reloder-10x | <<locked>> | 80% | 50,169 psi | 81% | 2917 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 36,550 psi | 59% | 2733 fps | 95.2% |
| Alliant Reloder-16 | <<locked>> | 92% | 38,653 psi | 62% | 2838 fps | 95% |
| Alliant Reloder-17 | <<locked>> | 86% | 35,839 psi | 58% | 2799 fps | 95.9% |
| Baschieri & Pellagri 106 | <<locked>> | 80% | 51,851 psi | 84% | 2887 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 39,798 psi | 64% | 2805 fps | 95.6% |
| Bofors RP3 | <<locked>> | 80% | 33,504 psi | 54% | 2671 fps | 96% |
| Hodgdon Benchmark | <<locked>> | 80% | 44,947 psi | 72% | 2831 fps | 99.3% |
| Hodgdon BL-C2 | <<locked>> | 80% | 41,394 psi | 67% | 2848 fps | 98.9% |
| Hodgdon CFE223 | <<locked>> | 80% | 45,165 psi | 73% | 2986 fps | 97.7% |
| Hodgdon H322 | <<locked>> | 80% | 48,936 psi | 79% | 2949 fps | 100% |
| Hodgdon H335 | <<locked>> | 80% | 49,951 psi | 81% | 2969 fps | 100% |
| Hodgdon H380 | <<locked>> | 86% | 42,119 psi | 68% | 2848 fps | 95.5% |
| Hodgdon H414 | <<locked>> | 98% | 50,198 psi | 81% | 3058 fps | 95.3% |
| Hodgdon H4895 | <<locked>> | 80% | 41,046 psi | 66% | 2825 fps | 97.7% |
| Hodgdon Hybrid 100V | <<locked>> | 92% | 35,128 psi | 57% | 2717 fps | 95.8% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 36,970 psi | 60% | 2782 fps | 97.1% |
| Hodgdon TrailBoss | <<locked>> | 80% | 25,889 psi | 42% | 1683 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 39,450 psi | 64% | 2772 fps | 97.3% |
| IMR 3031 | <<locked>> | 80% | 40,379 psi | 65% | 2838 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 36,376 psi | 59% | 2687 fps | 95.2% |
| IMR 4166 Enduron | <<locked>> | 88% | 50,299 psi | 81% | 2936 fps | 95.1% |
| IMR 4198 | <<locked>> | 80% | 50,285 psi | 81% | 2877 fps | 100% |
| IMR 4831 | <<locked>> | 94% | 39,508 psi | 64% | 2835 fps | 95.5% |
| IMR 4895 | <<locked>> | 80% | 37,420 psi | 60% | 2766 fps | 96.2% |
| IMR 8208 XBR | <<locked>> | 80% | 42,743 psi | 69% | 2828 fps | 98.6% |
| Lovex D073.5 | <<locked>> | 80% | 48,312 psi | 78% | 2923 fps | 99.8% |
| Lovex D073.6 | <<locked>> | 80% | 39,552 psi | 64% | 2795 fps | 99.2% |
| Lovex S060 | <<locked>> | 80% | 41,350 psi | 67% | 2759 fps | 97.3% |
| Lovex S062 | <<locked>> | 80% | 36,260 psi | 58% | 2697 fps | 97.2% |
| Lovex S065 | <<locked>> | 94% | 45,890 psi | 74% | 2894 fps | 95.6% |
| Lovex S070 | <<locked>> | 98% | 49,197 psi | 79% | 2976 fps | 95.2% |
| Norma 201 | <<locked>> | 80% | 39,871 psi | 64% | 2766 fps | 98.1% |
| Norma 202 | <<locked>> | 80% | 40,089 psi | 65% | 2782 fps | 99.6% |
| Norma 203B | <<locked>> | 80% | 35,940 psi | 58% | 2723 fps | 95.7% |
| Norma URP | <<locked>> | 94% | 41,118 psi | 66% | 2884 fps | 95.8% |
| Ramshot Big Game | <<locked>> | 80% | 35,592 psi | 57% | 2733 fps | 95.2% |
| Ramshot Hunter | <<locked>> | 98% | 46,079 psi | 74% | 2986 fps | 95.1% |
| Ramshot TAC | <<locked>> | 82% | 45,701 psi | 74% | 2884 fps | 95.8% |
| Ramshot Wild Boar | <<locked>> | 80% | 42,177 psi | 68% | 2848 fps | 97.4% |
| Ramshot X-Terminator | <<locked>> | 80% | 46,267 psi | 75% | 2877 fps | 98.2% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 26,121 psi | 42% | 1722 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 80% | 47,935 psi | 77% | 2923 fps | 99.9% |
| ReloadSwiss RS 50 | <<locked>> | 90% | 48,472 psi | 78% | 2943 fps | 95.4% |
| ReloadSwiss RS 52 | 32.2 gr | 80% | 37,797 psi | 61% | 2831 fps | 95.6% |
| ReloadSwiss RS 60 | 32.8 gr | 80% | 31,430 psi | 51% | 2684 fps | 96.7% |
| ReloadSwiss RS 62 | <<locked>> | 94% | 40,582 psi | 65% | 2897 fps | 95.3% |
| ReloadSwiss RS 70 | <<locked>> | 96% | 44,324 psi | 71% | 2976 fps | 95.5% |
| Rottweil R 901 | <<locked>> | 80% | 43,961 psi | 71% | 2831 fps | 99.8% |
| Rottweil R 902 | <<locked>> | 80% | 38,043 psi | 61% | 2717 fps | 97.7% |
| Rottweil R 903 | <<locked>> | 82% | 33,721 psi | 54% | 2667 fps | 95.7% |
| Shooters World Long Rifle | <<locked>> | 94% | 45,890 psi | 74% | 2894 fps | 95.6% |
| Shooters World Match Rifle | <<locked>> | 80% | 39,552 psi | 64% | 2795 fps | 99.2% |
| Shooters World Precision | <<locked>> | 80% | 36,260 psi | 58% | 2697 fps | 97.2% |
| Shooters World Tactical Rifle | <<locked>> | 80% | 51,010 psi | 82% | 2946 fps | 99.5% |
| SNPE Vectan SP 11 | <<locked>> | 82% | 34,911 psi | 56% | 2720 fps | 95% |
| SNPE Vectan SP 3 | <<locked>> | 80% | 48,037 psi | 77% | 2864 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 80% | 40,872 psi | 66% | 2792 fps | 95% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 39,233 psi | 63% | 2776 fps | 96.7% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 41,394 psi | 67% | 2733 fps | 99.7% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 34,185 psi | 55% | 2585 fps | 99.4% |
| SNPE Vectan Tubal 7000 | <<locked>> | 98% | 52,098 psi | 84% | 2949 fps | 95.5% |
| Somchem S321 | <<locked>> | 80% | 46,166 psi | 74% | 2913 fps | 99.4% |
| Somchem S335 | <<locked>> | 80% | 40,930 psi | 66% | 2733 fps | 99.9% |
| Somchem S341 | <<locked>> | 80% | 40,582 psi | 65% | 2792 fps | 97% |
| Somchem S355 | <<locked>> | 82% | 34,577 psi | 56% | 2674 fps | 95.7% |
| Somchem S365 | <<locked>> | 88% | 30,327 psi | 49% | 2648 fps | 95.3% |
| Unknown powder | <<locked>> | 92% | 42,119 psi | 68% | 2890 fps | 95.2% |
| Vihtavuori N130 | <<locked>> | 80% | 46,876 psi | 76% | 2812 fps | 100% |
| Vihtavuori N133 | <<locked>> | 80% | 41,582 psi | 67% | 2733 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 34,766 psi | 56% | 2641 fps | 99.9% |
| Vihtavuori N140 | <<locked>> | 80% | 38,000 psi | 61% | 2717 fps | 99.6% |
| Vihtavuori N150 | <<locked>> | 80% | 30,835 psi | 50% | 2556 fps | 95.9% |
| Vihtavuori N160 | <<locked>> | 92% | 40,437 psi | 65% | 2828 fps | 95.4% |
| Vihtavuori N530 | <<locked>> | 80% | 42,931 psi | 69% | 2828 fps | 98.8% |
| Vihtavuori N540 | <<locked>> | 80% | 36,550 psi | 59% | 2697 fps | 99.1% |
| Vihtavuori N550 | <<locked>> | 92% | 39,784 psi | 64% | 2831 fps | 95% |
| Winchester 6.5 StaBALL | <<locked>> | 86% | 33,605 psi | 54% | 2631 fps | 95.2% |
| Winchester 748 | <<locked>> | 80% | 42,134 psi | 68% | 2871 fps | 99.2% |
| Winchester 760 | <<locked>> | 98% | 50,589 psi | 82% | 3064 fps | 95.4% |
| Winchester StaBALL Match | <<locked>> | 80% | 38,551 psi | 62% | 2776 fps | 97.1% |
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 95 powders for 6 mm GT loaded with the .243 | 88gr | Berger Varmint. Alliant Power Pro 2000-MR delivers the highest muzzle velocity at 3,222 fps; across all powders the maximum-charge window runs from 1,886 fps to 3,222 fps. Accurate 4350 gives the best case fill at 100 %, and 95 of the 95 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (427 MPa), the top charges use 57–90 %, leaving at least 10 % headroom. The 88.0 gr projectile in 0.243" calls for a 1:9.5 twist; slower twists will usually not stabilise this weight. Accurate 4350, Alliant Reloder-16, Hodgdon H414 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 60, Alliant Power Pro 2000-MR, ReloadSwiss RS 52 rank at the top here: for 6 mm GT with the .243 | 88gr | Berger Varmint 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.