Load Specifications
Load data in caliber .300 H&H Mag. with .308 | 165gr | Frontier PH HPBT 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-16 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>> | 84% | 53,142 psi | 85% | 2795 fps | 100% |
| Accurate 2700 | <<locked>> | 86% | 54,824 psi | 88% | 2848 fps | 97.6% |
| Accurate 3100ᴾ | <<locked>> | 100% | 47,427 psi | 76% | 2815 fps | 97.9% |
| Accurate 4064 | <<locked>> | 86% | 53,258 psi | 85% | 2844 fps | 100% |
| Accurate 4350 | <<locked>> | 94% | 53,519 psi | 86% | 2936 fps | 99.7% |
| ADI AR 2206H | <<locked>> | 84% | 56,159 psi | 90% | 2923 fps | 100% |
| ADI AR 2208 | <<locked>> | 88% | 53,954 psi | 87% | 2874 fps | 99.9% |
| ADI AR 2209ᴾ | <<locked>> | 100% | 54,679 psi | 88% | 2966 fps | 96.8% |
| ADI Benchmark 8208 | <<locked>> | 82% | 55,187 psi | 88% | 2871 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 86% | 56,391 psi | 90% | 3051 fps | 100% |
| Alliant Power Pro Varmintᴾ | <<locked>> | 100% | 54,578 psi | 88% | 2966 fps | 96.9% |
| Alliant Reloder- TS 15.5 | <<locked>> | 88% | 54,360 psi | 87% | 2897 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 86% | 54,679 psi | 88% | 2917 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 96% | 54,259 psi | 87% | 2992 fps | 99.9% |
| Alliant Reloder-17 | <<locked>> | 92% | 55,622 psi | 89% | 3025 fps | 100% |
| Alliant Reloder-19ᴾ | <<locked>> | 100% | 53,766 psi | 86% | 2953 fps | 96.8% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 44,643 psi | 72% | 2838 fps | 99.8% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 39,160 psi | 63% | 2733 fps | 96.3% |
| Alliant Reloder-26ᴾ | <<locked>> | 100% | 50,705 psi | 81% | 3022 fps | 99.6% |
| Baschieri & Pellagri 107 | <<locked>> | 84% | 56,304 psi | 90% | 2943 fps | 99.9% |
| Bofors RP3 | <<locked>> | 88% | 55,172 psi | 88% | 2917 fps | 100% |
| Bofors RP7 | <<locked>> | 92% | 54,839 psi | 88% | 2887 fps | 97.8% |
| Hodgdon BL-C2 | <<locked>> | 82% | 54,897 psi | 88% | 2900 fps | 100% |
| Hodgdon H380 | <<locked>> | 88% | 55,666 psi | 89% | 2927 fps | 99.7% |
| Hodgdon H414 | <<locked>> | 94% | 56,043 psi | 90% | 2989 fps | 98.6% |
| Hodgdon H4350 | <<locked>> | 92% | 56,188 psi | 90% | 2949 fps | 97.5% |
| Hodgdon H4895 | <<locked>> | 82% | 53,534 psi | 86% | 2884 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 98% | 54,346 psi | 87% | 2917 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 84% | 53,127 psi | 85% | 2913 fps | 100% |
| Hodgdon Superformance | <<locked>> | 94% | 56,289 psi | 90% | 3025 fps | 98.4% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 35,926 psi | 58% | 1798 fps | 100% |
| Hodgdon VARGET | <<locked>> | 84% | 54,360 psi | 87% | 2881 fps | 100% |
| IMR 3031 | <<locked>> | 82% | 53,679 psi | 86% | 2861 fps | 100% |
| IMR 4064 | <<locked>> | 86% | 53,534 psi | 86% | 2858 fps | 99.9% |
| IMR 4166 Enduron | <<locked>> | 86% | 56,405 psi | 90% | 2890 fps | 98.5% |
| IMR 4350 | <<locked>> | 96% | 55,434 psi | 89% | 2917 fps | 98% |
| IMR 4451 Enduron | <<locked>> | 90% | 53,098 psi | 85% | 2861 fps | 98% |
| IMR 4831 | <<locked>> | 96% | 53,867 psi | 86% | 2927 fps | 99.8% |
| IMR 4895 | <<locked>> | 86% | 56,086 psi | 90% | 2946 fps | 100% |
| IMR 8208 XBR | <<locked>> | 82% | 55,187 psi | 88% | 2871 fps | 100% |
| Lovex D073.6 | <<locked>> | 82% | 52,895 psi | 85% | 2844 fps | 100% |
| Lovex S060 | <<locked>> | 84% | 55,463 psi | 89% | 2851 fps | 100% |
| Lovex S062 | <<locked>> | 86% | 53,505 psi | 86% | 2854 fps | 100% |
| Lovex S065 | <<locked>> | 94% | 56,159 psi | 90% | 2910 fps | 99.3% |
| Lovex S070 | <<locked>> | 94% | 54,128 psi | 87% | 2900 fps | 98.4% |
| Lovex S071ᴾ | <<locked>> | 100% | 39,465 psi | 63% | 2661 fps | 95.9% |
| Norma 201 | <<locked>> | 84% | 55,071 psi | 88% | 2867 fps | 100% |
| Norma 202 | <<locked>> | 84% | 55,680 psi | 89% | 2867 fps | 100% |
| Norma 203B | <<locked>> | 86% | 53,940 psi | 86% | 2904 fps | 100% |
| Norma 204 | <<locked>> | 96% | 56,130 psi | 90% | 2969 fps | 97% |
| Norma MRPᴾ | <<locked>> | 100% | 50,111 psi | 80% | 2972 fps | 97.6% |
| Norma URP | <<locked>> | 96% | 55,767 psi | 89% | 2976 fps | 99.8% |
| Ramshot Big Game | <<locked>> | 86% | 54,621 psi | 88% | 2930 fps | 100% |
| Ramshot Hunter | <<locked>> | 96% | 54,607 psi | 88% | 2972 fps | 99% |
| Ramshot TAC | <<locked>> | 82% | 55,216 psi | 89% | 2894 fps | 99.4% |
| Ramshot Wild Boar | <<locked>> | 82% | 54,984 psi | 88% | 2907 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 36,608 psi | 59% | 1844 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 88% | 55,912 psi | 90% | 2910 fps | 98.9% |
| ReloadSwiss RS 52 | <<locked>> | 84% | 55,376 psi | 89% | 2986 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 90% | 55,100 psi | 88% | 3018 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 94% | 53,214 psi | 85% | 2959 fps | 99.6% |
| ReloadSwiss RS 70 | <<locked>> | 96% | 55,927 psi | 90% | 3045 fps | 99.8% |
| Rottweil R 901 | <<locked>> | 82% | 55,869 psi | 90% | 2844 fps | 100% |
| Rottweil R 902 | <<locked>> | 86% | 55,637 psi | 89% | 2867 fps | 100% |
| Rottweil R 903 | <<locked>> | 90% | 55,027 psi | 88% | 2907 fps | 100% |
| Rottweil R 905ᴾ | <<locked>> | 100% | 52,837 psi | 85% | 2940 fps | 96.7% |
| Rottweil R 907 | <<locked>> | 92% | 54,839 psi | 88% | 2887 fps | 97.8% |
| Shooters World Long Rifle | <<locked>> | 94% | 56,159 psi | 90% | 2910 fps | 99.3% |
| Shooters World Match Rifle | <<locked>> | 82% | 52,895 psi | 85% | 2844 fps | 100% |
| Shooters World Precision | <<locked>> | 86% | 53,505 psi | 86% | 2854 fps | 100% |
| Shooters World SW4350 | <<locked>> | 94% | 54,128 psi | 87% | 2900 fps | 98.4% |
| SNPE Vectan SP 11 | <<locked>> | 88% | 53,156 psi | 85% | 2913 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 82% | 53,911 psi | 86% | 2871 fps | 99.5% |
| SNPE Vectan SP 9 | <<locked>> | 84% | 54,650 psi | 88% | 2890 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 84% | 56,173 psi | 90% | 2802 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 88% | 53,359 psi | 86% | 2756 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 94% | 56,391 psi | 90% | 2867 fps | 98.5% |
| SNPE Vectan Tubal 8000ᴾ | <<locked>> | 100% | 52,344 psi | 84% | 2933 fps | 96.6% |
| Somchem S335 | <<locked>> | 84% | 55,724 psi | 89% | 2799 fps | 100% |
| Somchem S341 | <<locked>> | 82% | 53,606 psi | 86% | 2861 fps | 100% |
| Somchem S355 | <<locked>> | 90% | 55,085 psi | 88% | 2904 fps | 100% |
| Somchem S365 | <<locked>> | 98% | 54,534 psi | 87% | 2979 fps | 100% |
| Somchem S385ᴾ | <<locked>> | 100% | 53,679 psi | 86% | 2920 fps | 97.7% |
| Vihtavuori N133 | <<locked>> | 82% | 53,287 psi | 85% | 2740 fps | 100% |
| Vihtavuori N135 | <<locked>> | 86% | 55,709 psi | 89% | 2828 fps | 100% |
| Vihtavuori N140 | <<locked>> | 86% | 56,289 psi | 90% | 2844 fps | 100% |
| Vihtavuori N150 | <<locked>> | 90% | 53,040 psi | 85% | 2831 fps | 100% |
| Vihtavuori N160 | <<locked>> | 94% | 54,694 psi | 88% | 2920 fps | 99.8% |
| Vihtavuori N530 | <<locked>> | 82% | 55,564 psi | 89% | 2871 fps | 100% |
| Vihtavuori N540 | <<locked>> | 86% | 54,360 psi | 87% | 2841 fps | 100% |
| Vihtavuori N550 | <<locked>> | 94% | 53,780 psi | 86% | 2923 fps | 99.6% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 49,937 psi | 80% | 2920 fps | 99.8% |
| Winchester 6.5 StaBALL | <<locked>> | 94% | 54,433 psi | 87% | 2890 fps | 100% |
| Winchester 748 | <<locked>> | 82% | 55,927 psi | 90% | 2917 fps | 100% |
| Winchester 760 | <<locked>> | 94% | 56,043 psi | 90% | 2989 fps | 98.6% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 40,219 psi | 64% | 2867 fps | 100% |
| Winchester StaBALL Match | <<locked>> | 84% | 54,723 psi | 88% | 2904 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% | 46,702 psi | 75% | 2700 fps | 100% |
| Accurate 2700 | <<locked>> | 80% | 45,121 psi | 72% | 2677 fps | 95.5% |
| Accurate 3100 | <<locked>> | 94% | 38,667 psi | 62% | 2644 fps | 95.6% |
| Accurate 4064 | <<locked>> | 80% | 44,179 psi | 71% | 2700 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 32,967 psi | 53% | 2526 fps | 95.5% |
| ADI AR 2206H | <<locked>> | 80% | 49,705 psi | 80% | 2815 fps | 99.9% |
| ADI AR 2208 | <<locked>> | 80% | 42,076 psi | 67% | 2661 fps | 98.6% |
| ADI AR 2209 | <<locked>> | 96% | 48,138 psi | 77% | 2851 fps | 95.2% |
| ADI Benchmark 8208 | <<locked>> | 80% | 51,764 psi | 83% | 2818 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 45,788 psi | 73% | 2864 fps | 99.3% |
| Alliant Power Pro Varmint | <<locked>> | 96% | 47,892 psi | 77% | 2844 fps | 95.3% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 42,308 psi | 68% | 2687 fps | 99.6% |
| Alliant Reloder-15 | <<locked>> | 80% | 45,266 psi | 73% | 2756 fps | 99.2% |
| Alliant Reloder-16 | 53.9 gr | 80% | 32,735 psi | 52% | 2536 fps | 95.4% |
| Alliant Reloder-17 | <<locked>> | 80% | 36,767 psi | 59% | 2667 fps | 98.6% |
| Alliant Reloder-19 | <<locked>> | 96% | 47,239 psi | 76% | 2838 fps | 95.2% |
| Alliant Reloder-23 | <<locked>> | 86% | 28,732 psi | 46% | 2448 fps | 95.3% |
| Alliant Reloder-25 | <<locked>> | 98% | 36,941 psi | 59% | 2677 fps | 95.4% |
| Alliant Reloder-26 | <<locked>> | 90% | 35,491 psi | 57% | 2694 fps | 95.9% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 49,197 psi | 79% | 2825 fps | 99.4% |
| Bofors RP3 | <<locked>> | 80% | 42,293 psi | 68% | 2697 fps | 99.6% |
| Bofors RP7 | <<locked>> | 84% | 42,786 psi | 69% | 2671 fps | 95.1% |
| Hodgdon BL-C2 | <<locked>> | 80% | 51,271 psi | 82% | 2844 fps | 100% |
| Hodgdon H380 | <<locked>> | 80% | 42,888 psi | 69% | 2703 fps | 97.9% |
| Hodgdon H414 | <<locked>> | 84% | 40,190 psi | 64% | 2694 fps | 95% |
| Hodgdon H4350 | <<locked>> | 86% | 46,398 psi | 74% | 2779 fps | 95.3% |
| Hodgdon H4895 | <<locked>> | 80% | 50,212 psi | 81% | 2828 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 30,298 psi | 49% | 2438 fps | 96.4% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 46,412 psi | 74% | 2802 fps | 99.9% |
| Hodgdon Superformance | 66 gr | 86% | 42,279 psi | 68% | 2766 fps | 95.1% |
| Hodgdon TrailBoss | <<locked>> | 80% | 26,919 psi | 43% | 1611 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 48,008 psi | 77% | 2776 fps | 99.9% |
| IMR 3031 | <<locked>> | 80% | 50,372 psi | 81% | 2812 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 44,222 psi | 71% | 2697 fps | 99.2% |
| IMR 4166 Enduron | <<locked>> | 80% | 46,673 psi | 75% | 2720 fps | 96.7% |
| IMR 4350 | <<locked>> | 88% | 43,178 psi | 69% | 2697 fps | 95.2% |
| IMR 4451 Enduron | <<locked>> | 82% | 41,640 psi | 67% | 2648 fps | 95.2% |
| IMR 4831 | <<locked>> | 80% | 31,850 psi | 51% | 2484 fps | 95.1% |
| IMR 4895 | <<locked>> | 80% | 46,427 psi | 74% | 2785 fps | 99.7% |
| IMR 8208 XBR | <<locked>> | 80% | 51,764 psi | 83% | 2818 fps | 100% |
| Lovex D073.6 | <<locked>> | 80% | 49,530 psi | 79% | 2795 fps | 100% |
| Lovex S060 | <<locked>> | 80% | 49,139 psi | 79% | 2746 fps | 99.8% |
| Lovex S062 | <<locked>> | 80% | 44,498 psi | 71% | 2703 fps | 99.9% |
| Lovex S065 | <<locked>> | 80% | 36,651 psi | 59% | 2543 fps | 95.3% |
| Lovex S070 | <<locked>> | 84% | 39,479 psi | 63% | 2625 fps | 95% |
| Lovex S071 | <<locked>> | 98% | 36,811 psi | 59% | 2602 fps | 95% |
| Norma 201 | <<locked>> | 80% | 48,646 psi | 78% | 2766 fps | 100% |
| Norma 202 | <<locked>> | 80% | 49,124 psi | 79% | 2769 fps | 100% |
| Norma 203B | <<locked>> | 80% | 44,643 psi | 72% | 2743 fps | 99.5% |
| Norma 204 | <<locked>> | 92% | 49,124 psi | 79% | 2851 fps | 95.4% |
| Norma MRP | <<locked>> | 96% | 43,671 psi | 70% | 2844 fps | 95.9% |
| Norma URP | <<locked>> | 80% | 33,112 psi | 53% | 2530 fps | 95.4% |
| Ramshot Big Game | <<locked>> | 80% | 44,556 psi | 71% | 2759 fps | 99.4% |
| Ramshot Hunter | <<locked>> | 86% | 39,276 psi | 63% | 2684 fps | 95.7% |
| Ramshot TAC | <<locked>> | 80% | 51,677 psi | 83% | 2835 fps | 98.9% |
| Ramshot Wild Boar | <<locked>> | 80% | 51,634 psi | 83% | 2854 fps | 99.9% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,224 psi | 44% | 1647 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 43,047 psi | 69% | 2684 fps | 96.5% |
| ReloadSwiss RS 52 | <<locked>> | 80% | 48,414 psi | 78% | 2867 fps | 99.6% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 39,117 psi | 63% | 2733 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 82% | 35,012 psi | 56% | 2602 fps | 95.9% |
| ReloadSwiss RS 70 | 61.9 gr | 84% | 36,912 psi | 59% | 2664 fps | 95.9% |
| Rottweil R 901 | <<locked>> | 80% | 52,663 psi | 84% | 2799 fps | 100% |
| Rottweil R 902 | <<locked>> | 80% | 46,311 psi | 74% | 2717 fps | 100% |
| Rottweil R 903 | <<locked>> | 80% | 39,827 psi | 64% | 2641 fps | 99.2% |
| Rottweil R 905 | <<locked>> | 96% | 46,137 psi | 74% | 2818 fps | 95.1% |
| Rottweil R 907 | <<locked>> | 84% | 42,786 psi | 69% | 2671 fps | 95.1% |
| Shooters World Long Rifle | <<locked>> | 80% | 36,651 psi | 59% | 2543 fps | 95.3% |
| Shooters World Match Rifle | <<locked>> | 80% | 49,530 psi | 79% | 2795 fps | 100% |
| Shooters World Precision | <<locked>> | 80% | 44,498 psi | 71% | 2703 fps | 99.9% |
| Shooters World SW4350 | <<locked>> | 84% | 39,479 psi | 63% | 2625 fps | 95% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 40,799 psi | 65% | 2690 fps | 98.8% |
| SNPE Vectan SP 7 | <<locked>> | 80% | 50,314 psi | 81% | 2812 fps | 99.1% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 48,138 psi | 77% | 2785 fps | 99.8% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 49,690 psi | 80% | 2707 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 41,727 psi | 67% | 2572 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 84% | 40,843 psi | 65% | 2592 fps | 95.2% |
| SNPE Vectan Tubal 8000 | <<locked>> | 98% | 48,921 psi | 78% | 2874 fps | 95.8% |
| Somchem S335 | <<locked>> | 80% | 49,385 psi | 79% | 2707 fps | 100% |
| Somchem S341 | <<locked>> | 80% | 50,067 psi | 80% | 2805 fps | 99.9% |
| Somchem S355 | <<locked>> | 80% | 40,408 psi | 65% | 2644 fps | 99.1% |
| Somchem S365 | <<locked>> | 80% | 29,718 psi | 48% | 2480 fps | 97.6% |
| Somchem S385 | <<locked>> | 94% | 44,063 psi | 71% | 2749 fps | 95.4% |
| Vihtavuori N133 | <<locked>> | 80% | 50,154 psi | 80% | 2697 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 46,209 psi | 74% | 2690 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 46,572 psi | 75% | 2700 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 38,479 psi | 62% | 2575 fps | 99.6% |
| Vihtavuori N160 | <<locked>> | 80% | 34,461 psi | 55% | 2530 fps | 95.8% |
| Vihtavuori N530 | <<locked>> | 80% | 52,040 psi | 83% | 2818 fps | 100% |
| Vihtavuori N540 | <<locked>> | 80% | 44,918 psi | 72% | 2690 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 33,982 psi | 54% | 2530 fps | 95.4% |
| Vihtavuori N555 | <<locked>> | 86% | 31,372 psi | 50% | 2530 fps | 95.5% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 33,968 psi | 54% | 2507 fps | 98% |
| Winchester 748 | <<locked>> | 80% | 52,359 psi | 84% | 2864 fps | 100% |
| Winchester 760 | <<locked>> | 84% | 40,190 psi | 64% | 2694 fps | 95% |
| Winchester StaBALL HD | <<locked>> | 90% | 28,877 psi | 46% | 2533 fps | 96.1% |
| Winchester StaBALL Match | <<locked>> | 80% | 47,935 psi | 77% | 2792 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 H&H Mag. loaded with the .308 | 165gr | Frontier PH HPBT. Alliant Power Pro 2000-MR delivers the highest muzzle velocity at 3,051 fps; across all powders the maximum-charge window runs from 1,798 fps to 3,051 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 58–90 %, leaving at least 10 % headroom. The 165.0 gr projectile in 0.308" calls for a 1:12.0 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-16, Hodgdon Superformance rank at the top here: for .300 H&H Mag. with the .308 | 165gr | Frontier PH HPBT 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.