Load Specifications
Load data in caliber .300 Win. Mag. with .308 | 155gr | Merlin Virtus bullet and 97 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Alliant Reloder-16, ReloadSwiss RS 70 and Hodgdon Superformance.
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 2495 | <<locked>> | 86% | 55,651 psi | 89% | 2953 fps | 100% |
| Accurate 2700 | <<locked>> | 86% | 54,650 psi | 88% | 2966 fps | 97.5% |
| Accurate 3100ᴾ | <<locked>> | 100% | 47,152 psi | 76% | 2920 fps | 97.8% |
| Accurate 4064 | <<locked>> | 88% | 56,086 psi | 90% | 3009 fps | 100% |
| Accurate 4350 | <<locked>> | 94% | 52,953 psi | 85% | 3048 fps | 99.7% |
| ADI AR 2206H | <<locked>> | 84% | 55,912 psi | 90% | 3041 fps | 100% |
| ADI AR 2208 | <<locked>> | 88% | 53,809 psi | 86% | 2992 fps | 99.9% |
| ADI AR 2209ᴾ | <<locked>> | 100% | 54,926 psi | 88% | 3091 fps | 96.7% |
| ADI Benchmark 8208 | <<locked>> | 82% | 54,882 psi | 88% | 2992 fps | 100% |
| Alliant AR-Comp | <<locked>> | 82% | 56,275 psi | 90% | 2963 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 84% | 52,562 psi | 84% | 3110 fps | 99.9% |
| Alliant Reloder- TS 15.5 | <<locked>> | 88% | 54,041 psi | 87% | 3015 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 86% | 54,404 psi | 87% | 3035 fps | 99.9% |
| Alliant Reloder-16 | <<locked>> | 96% | 54,346 psi | 87% | 3117 fps | 99.9% |
| Alliant Reloder-17 | <<locked>> | 92% | 55,651 psi | 89% | 3150 fps | 100% |
| Alliant Reloder-19ᴾ | <<locked>> | 100% | 53,925 psi | 86% | 3077 fps | 96.7% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 44,556 psi | 71% | 2949 fps | 99.8% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 38,986 psi | 63% | 2841 fps | 96.1% |
| Alliant Reloder-26ᴾ | <<locked>> | 100% | 50,778 psi | 81% | 3140 fps | 99.6% |
| Baschieri & Pellagri 107 | <<locked>> | 84% | 56,188 psi | 90% | 3061 fps | 99.9% |
| Bofors RP3 | <<locked>> | 88% | 54,679 psi | 88% | 3028 fps | 100% |
| Bofors RP7 | <<locked>> | 92% | 54,563 psi | 87% | 3005 fps | 97.7% |
| Hodgdon Benchmark | <<locked>> | 82% | 56,130 psi | 90% | 2969 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 82% | 54,476 psi | 87% | 3018 fps | 100% |
| Hodgdon H380 | <<locked>> | 88% | 55,448 psi | 89% | 3045 fps | 99.6% |
| Hodgdon H414 | <<locked>> | 94% | 56,014 psi | 90% | 3110 fps | 98.5% |
| Hodgdon H4350 | <<locked>> | 92% | 56,057 psi | 90% | 3068 fps | 97.4% |
| Hodgdon H4895 | <<locked>> | 82% | 53,185 psi | 85% | 3002 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 98% | 54,288 psi | 87% | 3035 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 84% | 53,011 psi | 85% | 3031 fps | 100% |
| Hodgdon Superformance | <<locked>> | 92% | 52,518 psi | 84% | 3081 fps | 97.7% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 35,752 psi | 57% | 1890 fps | 100% |
| Hodgdon VARGET | <<locked>> | 84% | 54,215 psi | 87% | 3002 fps | 100% |
| IMR 3031 | <<locked>> | 82% | 53,388 psi | 86% | 2982 fps | 100% |
| IMR 4064 | <<locked>> | 86% | 53,330 psi | 86% | 2976 fps | 99.9% |
| IMR 4166 Enduron | <<locked>> | 86% | 56,376 psi | 90% | 3012 fps | 98.4% |
| IMR 4350 | <<locked>> | 96% | 55,288 psi | 89% | 3035 fps | 97.9% |
| IMR 4451 Enduron | <<locked>> | 90% | 53,113 psi | 85% | 2982 fps | 97.9% |
| IMR 4831 | <<locked>> | 96% | 53,853 psi | 86% | 3045 fps | 99.8% |
| IMR 4895 | <<locked>> | 86% | 55,840 psi | 90% | 3068 fps | 100% |
| IMR 8208 XBR | <<locked>> | 82% | 54,882 psi | 88% | 2992 fps | 100% |
| Lovex D073.6 | <<locked>> | 84% | 56,043 psi | 90% | 3015 fps | 100% |
| Lovex S060 | <<locked>> | 84% | 55,259 psi | 89% | 2969 fps | 100% |
| Lovex S062 | <<locked>> | 86% | 53,142 psi | 85% | 2969 fps | 100% |
| Lovex S065 | <<locked>> | 94% | 55,970 psi | 90% | 3031 fps | 99.3% |
| Lovex S070 | <<locked>> | 94% | 53,780 psi | 86% | 3015 fps | 98.3% |
| Norma 201 | <<locked>> | 84% | 54,578 psi | 88% | 2986 fps | 100% |
| Norma 202 | <<locked>> | 84% | 55,259 psi | 89% | 2982 fps | 100% |
| Norma 203B | <<locked>> | 86% | 53,650 psi | 86% | 3022 fps | 100% |
| Norma 204 | <<locked>> | 96% | 56,115 psi | 90% | 3087 fps | 96.9% |
| Norma MRPᴾ | <<locked>> | 100% | 50,169 psi | 80% | 3091 fps | 97.5% |
| Norma URP | <<locked>> | 96% | 55,898 psi | 90% | 3097 fps | 99.8% |
| Ramshot Big Game | <<locked>> | 86% | 54,578 psi | 88% | 3051 fps | 100% |
| Ramshot Hunter | <<locked>> | 96% | 54,607 psi | 88% | 3091 fps | 99% |
| Ramshot TAC | <<locked>> | 82% | 54,998 psi | 88% | 3012 fps | 99.3% |
| Ramshot Wild Boar | <<locked>> | 82% | 54,897 psi | 88% | 3025 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 36,303 psi | 58% | 1936 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 88% | 55,637 psi | 89% | 3028 fps | 98.8% |
| ReloadSwiss RS 52 | <<locked>> | 84% | 55,361 psi | 89% | 3110 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 90% | 55,114 psi | 88% | 3143 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 94% | 53,171 psi | 85% | 3074 fps | 99.6% |
| ReloadSwiss RS 70 | <<locked>> | 96% | 56,072 psi | 90% | 3166 fps | 99.8% |
| Rottweil R 901 | <<locked>> | 82% | 55,143 psi | 88% | 2963 fps | 100% |
| Rottweil R 902 | <<locked>> | 86% | 55,056 psi | 88% | 2982 fps | 100% |
| Rottweil R 903 | <<locked>> | 90% | 54,781 psi | 88% | 3025 fps | 100% |
| Rottweil R 905ᴾ | <<locked>> | 100% | 52,765 psi | 85% | 3054 fps | 96.6% |
| Rottweil R 907 | <<locked>> | 92% | 54,563 psi | 87% | 3005 fps | 97.7% |
| Shooters World Long Rifle | <<locked>> | 94% | 55,970 psi | 90% | 3031 fps | 99.3% |
| Shooters World Match Rifle | <<locked>> | 84% | 56,043 psi | 90% | 3015 fps | 100% |
| Shooters World Precision | <<locked>> | 86% | 53,142 psi | 85% | 2969 fps | 100% |
| Shooters World SW4350 | <<locked>> | 94% | 53,780 psi | 86% | 3015 fps | 98.3% |
| SNPE Vectan SP 11 | <<locked>> | 88% | 52,953 psi | 85% | 3031 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 82% | 53,606 psi | 86% | 2989 fps | 99.4% |
| SNPE Vectan SP 9 | <<locked>> | 84% | 54,621 psi | 88% | 3015 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 84% | 55,898 psi | 90% | 2920 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 88% | 53,214 psi | 85% | 2871 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 94% | 56,202 psi | 90% | 2982 fps | 98.4% |
| SNPE Vectan Tubal 8000ᴾ | <<locked>> | 100% | 52,272 psi | 84% | 3051 fps | 96.5% |
| Somchem S335 | <<locked>> | 84% | 55,332 psi | 89% | 2917 fps | 100% |
| Somchem S341 | <<locked>> | 82% | 53,403 psi | 86% | 2979 fps | 100% |
| Somchem S355 | <<locked>> | 90% | 54,781 psi | 88% | 3018 fps | 100% |
| Somchem S365 | <<locked>> | 98% | 54,447 psi | 87% | 3097 fps | 100% |
| Somchem S385ᴾ | <<locked>> | 100% | 53,563 psi | 86% | 3035 fps | 97.6% |
| Vihtavuori N133 | <<locked>> | 84% | 56,362 psi | 90% | 2904 fps | 100% |
| Vihtavuori N135 | <<locked>> | 86% | 55,405 psi | 89% | 2946 fps | 100% |
| Vihtavuori N140 | <<locked>> | 86% | 55,912 psi | 90% | 2963 fps | 100% |
| Vihtavuori N150 | <<locked>> | 92% | 56,391 psi | 90% | 2999 fps | 100% |
| Vihtavuori N160 | <<locked>> | 94% | 54,447 psi | 87% | 3035 fps | 99.7% |
| Vihtavuori N530 | <<locked>> | 82% | 55,201 psi | 89% | 2986 fps | 100% |
| Vihtavuori N540 | <<locked>> | 86% | 54,143 psi | 87% | 2956 fps | 100% |
| Vihtavuori N550 | <<locked>> | 94% | 53,708 psi | 86% | 3041 fps | 99.6% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 49,545 psi | 79% | 3028 fps | 99.7% |
| Winchester 6.5 StaBALL | <<locked>> | 94% | 54,447 psi | 87% | 3009 fps | 100% |
| Winchester 748 | <<locked>> | 82% | 55,724 psi | 89% | 3038 fps | 100% |
| Winchester 760 | <<locked>> | 94% | 56,014 psi | 90% | 3110 fps | 98.5% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 39,958 psi | 64% | 2972 fps | 99.9% |
| Winchester StaBALL Match | <<locked>> | 84% | 54,520 psi | 87% | 3018 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% | 45,629 psi | 73% | 2802 fps | 100% |
| Accurate 2700 | <<locked>> | 80% | 44,759 psi | 72% | 2785 fps | 95.2% |
| Accurate 3100 | <<locked>> | 94% | 38,000 psi | 61% | 2733 fps | 95.2% |
| Accurate 4064 | <<locked>> | 80% | 43,192 psi | 69% | 2799 fps | 100% |
| Accurate 4350 | <<locked>> | 82% | 34,664 psi | 56% | 2677 fps | 95.9% |
| ADI AR 2206H | <<locked>> | 80% | 49,284 psi | 79% | 2930 fps | 99.8% |
| ADI AR 2208 | <<locked>> | 80% | 41,901 psi | 67% | 2772 fps | 98.5% |
| ADI AR 2209 | <<locked>> | 96% | 47,935 psi | 77% | 2963 fps | 95% |
| ADI Benchmark 8208 | <<locked>> | 80% | 51,459 psi | 83% | 2936 fps | 100% |
| Alliant AR-Comp | <<locked>> | 80% | 52,707 psi | 85% | 2913 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 45,426 psi | 73% | 2976 fps | 99.2% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 41,742 psi | 67% | 2792 fps | 99.5% |
| Alliant Reloder-15 | <<locked>> | 80% | 44,802 psi | 72% | 2864 fps | 99.1% |
| Alliant Reloder-16 | 57.6 gr | 80% | 32,271 psi | 52% | 2631 fps | 95% |
| Alliant Reloder-17 | <<locked>> | 80% | 36,361 psi | 58% | 2769 fps | 98.3% |
| Alliant Reloder-19 | <<locked>> | 96% | 47,224 psi | 76% | 2949 fps | 95% |
| Alliant Reloder-23 | <<locked>> | 88% | 30,081 psi | 48% | 2592 fps | 95.8% |
| Alliant Reloder-25 | <<locked>> | 98% | 36,521 psi | 59% | 2776 fps | 95% |
| Alliant Reloder-26 | <<locked>> | 90% | 35,070 psi | 56% | 2785 fps | 95.5% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 48,965 psi | 79% | 2940 fps | 99.3% |
| Bofors RP3 | <<locked>> | 80% | 41,568 psi | 67% | 2795 fps | 99.5% |
| Bofors RP7 | <<locked>> | 86% | 45,150 psi | 72% | 2831 fps | 95.6% |
| Hodgdon Benchmark | <<locked>> | 80% | 52,866 psi | 85% | 2920 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 80% | 50,792 psi | 81% | 2956 fps | 100% |
| Hodgdon H380 | <<locked>> | 80% | 42,380 psi | 68% | 2805 fps | 97.7% |
| Hodgdon H414 | <<locked>> | 86% | 42,583 psi | 68% | 2858 fps | 95.6% |
| Hodgdon H4350 | <<locked>> | 86% | 46,064 psi | 74% | 2884 fps | 95% |
| Hodgdon H4895 | <<locked>> | 80% | 49,792 psi | 80% | 2943 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 29,762 psi | 48% | 2526 fps | 95.9% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 46,122 psi | 74% | 2913 fps | 99.9% |
| Hodgdon Superformance | 72.2 gr | 88% | 45,295 psi | 73% | 2943 fps | 95.9% |
| Hodgdon TrailBoss | <<locked>> | 80% | 26,556 psi | 43% | 1690 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 47,718 psi | 77% | 2890 fps | 99.8% |
| IMR 3031 | <<locked>> | 80% | 50,024 psi | 80% | 2930 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 44,048 psi | 71% | 2808 fps | 99% |
| IMR 4166 Enduron | <<locked>> | 80% | 46,427 psi | 74% | 2835 fps | 96.6% |
| IMR 4350 | <<locked>> | 88% | 42,946 psi | 69% | 2805 fps | 95% |
| IMR 4451 Enduron | <<locked>> | 84% | 43,976 psi | 71% | 2812 fps | 95.8% |
| IMR 4831 | <<locked>> | 82% | 33,591 psi | 54% | 2635 fps | 95.6% |
| IMR 4895 | <<locked>> | 80% | 45,963 psi | 74% | 2894 fps | 99.6% |
| IMR 8208 XBR | <<locked>> | 80% | 51,459 psi | 83% | 2936 fps | 100% |
| Lovex D073.6 | <<locked>> | 80% | 48,979 psi | 79% | 2907 fps | 100% |
| Lovex S060 | <<locked>> | 80% | 48,776 psi | 78% | 2861 fps | 99.8% |
| Lovex S062 | <<locked>> | 80% | 43,947 psi | 70% | 2808 fps | 99.8% |
| Lovex S065 | <<locked>> | 82% | 38,493 psi | 62% | 2694 fps | 95.7% |
| Lovex S070 | <<locked>> | 86% | 41,524 psi | 67% | 2779 fps | 95.5% |
| Norma 201 | <<locked>> | 80% | 48,008 psi | 77% | 2874 fps | 100% |
| Norma 202 | <<locked>> | 80% | 48,588 psi | 78% | 2877 fps | 100% |
| Norma 203B | <<locked>> | 80% | 44,179 psi | 71% | 2851 fps | 99.3% |
| Norma 204 | <<locked>> | 92% | 48,950 psi | 78% | 2963 fps | 95.2% |
| Norma MRP | <<locked>> | 96% | 43,511 psi | 70% | 2956 fps | 95.7% |
| Norma URP | <<locked>> | 82% | 34,853 psi | 56% | 2680 fps | 95.8% |
| Ramshot Big Game | <<locked>> | 80% | 44,135 psi | 71% | 2864 fps | 99.2% |
| Ramshot Hunter | <<locked>> | 86% | 38,914 psi | 62% | 2782 fps | 95.3% |
| Ramshot TAC | <<locked>> | 80% | 51,401 psi | 82% | 2949 fps | 98.8% |
| Ramshot Wild Boar | <<locked>> | 80% | 51,242 psi | 82% | 2966 fps | 99.9% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 26,948 psi | 43% | 1729 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 42,714 psi | 68% | 2789 fps | 96.3% |
| ReloadSwiss RS 52 | <<locked>> | 80% | 47,993 psi | 77% | 2982 fps | 99.5% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 38,769 psi | 62% | 2838 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 82% | 34,548 psi | 55% | 2694 fps | 95.4% |
| ReloadSwiss RS 70 | 66.2 gr | 84% | 36,637 psi | 59% | 2766 fps | 95.6% |
| Rottweil R 901 | <<locked>> | 80% | 51,866 psi | 83% | 2910 fps | 100% |
| Rottweil R 902 | <<locked>> | 80% | 45,745 psi | 73% | 2825 fps | 99.9% |
| Rottweil R 903 | <<locked>> | 80% | 39,044 psi | 63% | 2736 fps | 98.9% |
| Rottweil R 905 | <<locked>> | 98% | 49,443 psi | 79% | 2995 fps | 95.9% |
| Rottweil R 907 | <<locked>> | 86% | 45,150 psi | 72% | 2831 fps | 95.6% |
| Shooters World Long Rifle | <<locked>> | 82% | 38,493 psi | 62% | 2694 fps | 95.7% |
| Shooters World Match Rifle | <<locked>> | 80% | 48,979 psi | 79% | 2907 fps | 100% |
| Shooters World Precision | <<locked>> | 80% | 43,947 psi | 70% | 2808 fps | 99.8% |
| Shooters World SW4350 | <<locked>> | 86% | 41,524 psi | 67% | 2779 fps | 95.5% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 40,364 psi | 65% | 2795 fps | 98.6% |
| SNPE Vectan SP 7 | <<locked>> | 80% | 49,937 psi | 80% | 2923 fps | 99% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 47,761 psi | 77% | 2897 fps | 99.7% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 49,284 psi | 79% | 2822 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 41,292 psi | 66% | 2677 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 86% | 43,134 psi | 69% | 2753 fps | 95.8% |
| SNPE Vectan Tubal 8000 | <<locked>> | 98% | 48,994 psi | 79% | 2989 fps | 95.7% |
| Somchem S335 | <<locked>> | 80% | 48,863 psi | 78% | 2818 fps | 100% |
| Somchem S341 | <<locked>> | 80% | 49,806 psi | 80% | 2917 fps | 99.8% |
| Somchem S355 | <<locked>> | 80% | 39,769 psi | 64% | 2743 fps | 98.9% |
| Somchem S365 | <<locked>> | 80% | 29,153 psi | 47% | 2566 fps | 97.2% |
| Somchem S385 | <<locked>> | 94% | 43,700 psi | 70% | 2854 fps | 95.2% |
| Vihtavuori N133 | <<locked>> | 80% | 49,792 psi | 80% | 2808 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 45,687 psi | 73% | 2799 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 46,021 psi | 74% | 2808 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 37,840 psi | 61% | 2671 fps | 99.4% |
| Vihtavuori N160 | <<locked>> | 80% | 33,968 psi | 54% | 2625 fps | 95.4% |
| Vihtavuori N530 | <<locked>> | 80% | 51,605 psi | 83% | 2930 fps | 100% |
| Vihtavuori N540 | <<locked>> | 80% | 44,527 psi | 71% | 2799 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 33,475 psi | 54% | 2621 fps | 95% |
| Vihtavuori N555 | <<locked>> | 88% | 32,880 psi | 53% | 2671 fps | 95.9% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 33,547 psi | 54% | 2598 fps | 97.7% |
| Winchester 748 | <<locked>> | 80% | 52,141 psi | 84% | 2986 fps | 100% |
| Winchester 760 | <<locked>> | 86% | 42,786 psi | 69% | 2864 fps | 95.7% |
| Winchester StaBALL HD | <<locked>> | 90% | 28,427 psi | 46% | 2615 fps | 95.4% |
| Winchester StaBALL Match | <<locked>> | 80% | 47,543 psi | 76% | 2900 fps | 99.9% |
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 .300 Win. Mag. loaded with the .308 | 155gr | Merlin Virtus. ReloadSwiss RS 70 delivers the highest muzzle velocity at 3,166 fps; across all powders the maximum-charge window runs from 1,890 fps to 3,166 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 (430 MPa), the top charges use 57–90 %, leaving at least 10 % headroom. The 155.0 gr projectile in 0.308" calls for a 1:12.5 twist; slower twists will usually not stabilise this weight. Accurate 3100, ADI AR 2209, Alliant Reloder-19 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-16, ReloadSwiss RS 70, Hodgdon Superformance rank at the top here: for .300 Win. Mag. with the .308 | 155gr | 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.