Load Specifications
Load data in caliber .300 H&H Mag. with .308 | 180gr | Sellier & Bellot HPC 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 Alliant Reloder-26.
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% | 56,014 psi | 90% | 2710 fps | 100% |
| Accurate 2700 | <<locked>> | 84% | 54,012 psi | 87% | 2726 fps | 98.3% |
| Accurate 3100ᴾ | <<locked>> | 100% | 50,763 psi | 81% | 2759 fps | 99.1% |
| Accurate 4064 | <<locked>> | 84% | 52,895 psi | 85% | 2717 fps | 100% |
| Accurate 4350 | <<locked>> | 92% | 53,084 psi | 85% | 2815 fps | 99.9% |
| Accurate High Countryᴾ | <<locked>> | 100% | 55,550 psi | 89% | 2956 fps | 97.2% |
| ADI AR 2206H | <<locked>> | 82% | 55,477 psi | 89% | 2792 fps | 100% |
| ADI AR 2208 | <<locked>> | 86% | 53,229 psi | 85% | 2746 fps | 100% |
| ADI AR 2209 | <<locked>> | 98% | 54,375 psi | 87% | 2854 fps | 97.7% |
| Alliant Power Pro 2000-MR | <<locked>> | 84% | 55,724 psi | 89% | 2917 fps | 100% |
| Alliant Power Pro Varmint | <<locked>> | 98% | 54,157 psi | 87% | 2848 fps | 97.7% |
| Alliant Reloder- TS 15.5 | <<locked>> | 86% | 53,882 psi | 86% | 2769 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 84% | 54,172 psi | 87% | 2789 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 94% | 53,940 psi | 86% | 2867 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 90% | 55,288 psi | 89% | 2897 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 98% | 53,417 psi | 86% | 2838 fps | 97.6% |
| Alliant Reloder-22ᴾ | <<locked>> | 100% | 50,444 psi | 81% | 2835 fps | 97.2% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 47,630 psi | 76% | 2779 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 41,611 psi | 67% | 2694 fps | 98.2% |
| Alliant Reloder-26ᴾ | <<locked>> | 100% | 54,534 psi | 87% | 2969 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 82% | 55,477 psi | 89% | 2808 fps | 100% |
| Bofors RP15ᴾ | <<locked>> | 100% | 46,427 psi | 74% | 2762 fps | 96.1% |
| Bofors RP3 | <<locked>> | 86% | 54,621 psi | 88% | 2785 fps | 100% |
| Bofors RP5ᴾ | <<locked>> | 100% | 50,444 psi | 81% | 2835 fps | 97.2% |
| Bofors RP7 | <<locked>> | 90% | 54,056 psi | 87% | 2766 fps | 98.5% |
| Hodgdon H380 | <<locked>> | 86% | 54,998 psi | 88% | 2799 fps | 99.9% |
| Hodgdon H414 | <<locked>> | 92% | 55,550 psi | 89% | 2867 fps | 99.1% |
| Hodgdon H4350 | <<locked>> | 90% | 55,405 psi | 89% | 2822 fps | 98.2% |
| Hodgdon H4831ᴾ | <<locked>> | 100% | 55,767 psi | 89% | 2848 fps | 96% |
| Hodgdon H4895 | <<locked>> | 82% | 56,072 psi | 90% | 2799 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 96% | 54,128 psi | 87% | 2795 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 84% | 56,173 psi | 90% | 2835 fps | 100% |
| Hodgdon Superformance | <<locked>> | 92% | 55,738 psi | 89% | 2904 fps | 99% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,216 psi | 58% | 1722 fps | 100% |
| Hodgdon VARGET | <<locked>> | 82% | 53,621 psi | 86% | 2749 fps | 100% |
| IMR 4064 | <<locked>> | 86% | 56,072 psi | 90% | 2779 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 84% | 55,347 psi | 89% | 2759 fps | 99% |
| IMR 4350 | <<locked>> | 94% | 54,737 psi | 88% | 2795 fps | 98.6% |
| IMR 4451 Enduron | <<locked>> | 90% | 55,724 psi | 89% | 2792 fps | 99% |
| IMR 4831 | <<locked>> | 94% | 53,708 psi | 86% | 2805 fps | 100% |
| IMR 4895 | <<locked>> | 84% | 55,608 psi | 89% | 2818 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 98% | 54,012 psi | 87% | 2782 fps | 95.9% |
| Lovex D073.6 | <<locked>> | 82% | 55,811 psi | 89% | 2762 fps | 100% |
| Lovex S060 | <<locked>> | 82% | 54,505 psi | 87% | 2717 fps | 100% |
| Lovex S062 | <<locked>> | 86% | 56,144 psi | 90% | 2772 fps | 100% |
| Lovex S065 | <<locked>> | 92% | 55,767 psi | 89% | 2792 fps | 99.7% |
| Lovex S070 | <<locked>> | 92% | 53,417 psi | 86% | 2776 fps | 98.9% |
| Lovex S071ᴾ | <<locked>> | 100% | 42,221 psi | 68% | 2612 fps | 97.6% |
| Norma 201 | <<locked>> | 82% | 54,302 psi | 87% | 2736 fps | 100% |
| Norma 202 | <<locked>> | 82% | 54,926 psi | 88% | 2733 fps | 100% |
| Norma 203B | <<locked>> | 84% | 53,476 psi | 86% | 2779 fps | 100% |
| Norma 204 | <<locked>> | 94% | 55,564 psi | 89% | 2848 fps | 97.7% |
| Norma MRPᴾ | <<locked>> | 100% | 53,679 psi | 86% | 2923 fps | 99% |
| Norma URP | <<locked>> | 94% | 55,550 psi | 89% | 2851 fps | 100% |
| Ramshot Big Game | <<locked>> | 84% | 53,940 psi | 86% | 2802 fps | 100% |
| Ramshot Hunter | <<locked>> | 94% | 54,302 psi | 87% | 2851 fps | 99.5% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 44,063 psi | 71% | 2697 fps | 96.1% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 36,970 psi | 59% | 1765 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 86% | 55,042 psi | 88% | 2785 fps | 99.3% |
| ReloadSwiss RS 52 | <<locked>> | 82% | 54,868 psi | 88% | 2854 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 88% | 54,665 psi | 88% | 2887 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 92% | 52,808 psi | 85% | 2835 fps | 99.9% |
| ReloadSwiss RS 70 | <<locked>> | 94% | 55,332 psi | 89% | 2920 fps | 100% |
| Rottweil R 902 | <<locked>> | 84% | 54,868 psi | 88% | 2736 fps | 100% |
| Rottweil R 903 | <<locked>> | 88% | 54,491 psi | 87% | 2779 fps | 100% |
| Rottweil R 904 | <<locked>> | 98% | 56,130 psi | 90% | 2825 fps | 96.9% |
| Rottweil R 905ᴾ | <<locked>> | 100% | 56,289 psi | 90% | 2881 fps | 98.2% |
| Rottweil R 907 | <<locked>> | 90% | 54,056 psi | 87% | 2766 fps | 98.5% |
| Shooters World Long Rifle | <<locked>> | 92% | 55,767 psi | 89% | 2792 fps | 99.7% |
| Shooters World Match Rifle | <<locked>> | 82% | 55,811 psi | 89% | 2762 fps | 100% |
| Shooters World Precision | <<locked>> | 86% | 56,144 psi | 90% | 2772 fps | 100% |
| Shooters World SW4350 | <<locked>> | 92% | 53,417 psi | 86% | 2776 fps | 98.9% |
| SNPE Vectan SP 11 | <<locked>> | 88% | 56,289 psi | 90% | 2841 fps | 100% |
| SNPE Vectan SP 9 | <<locked>> | 82% | 53,838 psi | 86% | 2762 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 82% | 55,288 psi | 89% | 2671 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 88% | 55,854 psi | 90% | 2671 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 92% | 55,651 psi | 89% | 2746 fps | 99% |
| SNPE Vectan Tubal 8000ᴾ | <<locked>> | 100% | 55,782 psi | 89% | 2874 fps | 98.1% |
| Somchem S335 | <<locked>> | 82% | 54,868 psi | 88% | 2667 fps | 100% |
| Somchem S355 | <<locked>> | 88% | 54,665 psi | 88% | 2776 fps | 100% |
| Somchem S365 | <<locked>> | 96% | 54,462 psi | 87% | 2851 fps | 100% |
| Somchem S385 | <<locked>> | 98% | 53,447 psi | 86% | 2805 fps | 98.4% |
| Vihtavuori N133 | <<locked>> | 82% | 55,782 psi | 89% | 2651 fps | 100% |
| Vihtavuori N135 | <<locked>> | 84% | 54,969 psi | 88% | 2694 fps | 100% |
| Vihtavuori N140 | <<locked>> | 84% | 55,347 psi | 89% | 2710 fps | 100% |
| Vihtavuori N150 | <<locked>> | 90% | 55,970 psi | 90% | 2753 fps | 100% |
| Vihtavuori N160 | <<locked>> | 92% | 54,128 psi | 87% | 2795 fps | 99.9% |
| Vihtavuori N165ᴾ | <<locked>> | 100% | 49,153 psi | 79% | 2723 fps | 97.3% |
| Vihtavuori N540 | <<locked>> | 84% | 53,577 psi | 86% | 2707 fps | 100% |
| Vihtavuori N550 | <<locked>> | 92% | 53,316 psi | 85% | 2802 fps | 99.9% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 53,490 psi | 86% | 2858 fps | 100% |
| Vihtavuori N560ᴾ | <<locked>> | 100% | 54,201 psi | 87% | 2910 fps | 96.1% |
| Winchester 6.5 StaBALL | <<locked>> | 92% | 53,780 psi | 86% | 2766 fps | 100% |
| Winchester 760 | <<locked>> | 92% | 55,550 psi | 89% | 2867 fps | 99.1% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 42,931 psi | 69% | 2825 fps | 100% |
| Winchester StaBALL Match | <<locked>> | 82% | 53,824 psi | 86% | 2769 fps | 100% |
| Winchester Supreme 780ᴾ | <<locked>> | 100% | 53,548 psi | 86% | 2799 fps | 97.5% |
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% | 49,182 psi | 79% | 2618 fps | 100% |
| Accurate 2700 | <<locked>> | 80% | 47,282 psi | 76% | 2615 fps | 97% |
| Accurate 3100 | <<locked>> | 90% | 36,201 psi | 58% | 2490 fps | 95.9% |
| Accurate 4064 | <<locked>> | 80% | 46,601 psi | 75% | 2621 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 35,157 psi | 56% | 2480 fps | 97.3% |
| Accurate High Country | <<locked>> | 96% | 48,167 psi | 77% | 2828 fps | 95.4% |
| ADI AR 2206H | <<locked>> | 80% | 51,996 psi | 83% | 2736 fps | 100% |
| ADI AR 2208 | <<locked>> | 80% | 44,222 psi | 71% | 2595 fps | 99.5% |
| ADI AR 2209 | <<locked>> | 92% | 44,701 psi | 72% | 2680 fps | 95.3% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 48,472 psi | 78% | 2799 fps | 99.9% |
| Alliant Power Pro Varmint | <<locked>> | 92% | 44,672 psi | 72% | 2680 fps | 95.5% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 44,512 psi | 71% | 2618 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 47,572 psi | 76% | 2684 fps | 99.8% |
| Alliant Reloder-16 | 53.2 gr | 80% | 34,650 psi | 56% | 2490 fps | 97.4% |
| Alliant Reloder-17 | <<locked>> | 80% | 39,015 psi | 63% | 2612 fps | 99.6% |
| Alliant Reloder-19 | <<locked>> | 92% | 44,121 psi | 71% | 2674 fps | 95.4% |
| Alliant Reloder-22 | <<locked>> | 96% | 44,324 psi | 71% | 2723 fps | 95.6% |
| Alliant Reloder-23 | <<locked>> | 82% | 26,992 psi | 43% | 2303 fps | 95.6% |
| Alliant Reloder-25 | <<locked>> | 94% | 34,461 psi | 55% | 2523 fps | 95.6% |
| Alliant Reloder-26 | 63.1 gr | 86% | 32,909 psi | 53% | 2526 fps | 95.9% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 51,793 psi | 83% | 2756 fps | 99.9% |
| Bofors RP15 | <<locked>> | 98% | 43,468 psi | 70% | 2703 fps | 95.2% |
| Bofors RP3 | <<locked>> | 80% | 44,701 psi | 72% | 2628 fps | 100% |
| Bofors RP5 | <<locked>> | 96% | 44,324 psi | 71% | 2723 fps | 95.6% |
| Bofors RP7 | <<locked>> | 80% | 39,595 psi | 63% | 2500 fps | 95.2% |
| Hodgdon H380 | <<locked>> | 80% | 45,165 psi | 72% | 2638 fps | 99% |
| Hodgdon H414 | <<locked>> | 80% | 37,318 psi | 60% | 2526 fps | 95.1% |
| Hodgdon H4350 | <<locked>> | 82% | 42,960 psi | 69% | 2605 fps | 95.4% |
| Hodgdon H4831 | <<locked>> | 98% | 52,098 psi | 84% | 2789 fps | 95.1% |
| Hodgdon H4895 | <<locked>> | 80% | 52,605 psi | 84% | 2746 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 32,242 psi | 52% | 2392 fps | 98.1% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 49,255 psi | 79% | 2733 fps | 100% |
| Hodgdon Superformance | <<locked>> | 82% | 38,885 psi | 62% | 2589 fps | 95.1% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,050 psi | 43% | 1539 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 50,473 psi | 81% | 2700 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 46,485 psi | 75% | 2628 fps | 99.8% |
| IMR 4166 Enduron | <<locked>> | 80% | 48,950 psi | 78% | 2657 fps | 98.1% |
| IMR 4350 | <<locked>> | 84% | 40,205 psi | 64% | 2536 fps | 95.4% |
| IMR 4451 Enduron | <<locked>> | 80% | 41,046 psi | 66% | 2533 fps | 96.1% |
| IMR 4831 | <<locked>> | 80% | 34,026 psi | 55% | 2438 fps | 97% |
| IMR 4895 | <<locked>> | 80% | 48,805 psi | 78% | 2713 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 96% | 50,662 psi | 81% | 2726 fps | 95.1% |
| Lovex D073.6 | <<locked>> | 80% | 52,272 psi | 84% | 2713 fps | 100% |
| Lovex S060 | <<locked>> | 80% | 51,343 psi | 82% | 2671 fps | 100% |
| Lovex S062 | <<locked>> | 80% | 46,862 psi | 75% | 2628 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 38,464 psi | 62% | 2480 fps | 96.9% |
| Lovex S070 | <<locked>> | 80% | 36,738 psi | 59% | 2461 fps | 95.1% |
| Lovex S071 | <<locked>> | 94% | 34,766 psi | 56% | 2454 fps | 95.3% |
| Norma 201 | <<locked>> | 80% | 50,879 psi | 82% | 2684 fps | 100% |
| Norma 202 | <<locked>> | 80% | 51,445 psi | 82% | 2684 fps | 100% |
| Norma 203B | <<locked>> | 80% | 46,949 psi | 75% | 2671 fps | 99.9% |
| Norma 204 | <<locked>> | 88% | 45,469 psi | 73% | 2677 fps | 95.5% |
| Norma MRP | <<locked>> | 90% | 37,942 psi | 61% | 2615 fps | 95% |
| Norma URP | <<locked>> | 80% | 35,114 psi | 56% | 2477 fps | 97.1% |
| Ramshot Big Game | <<locked>> | 80% | 47,123 psi | 76% | 2694 fps | 99.9% |
| Ramshot Hunter | <<locked>> | 82% | 36,419 psi | 58% | 2516 fps | 95.7% |
| Ramshot Magnum | <<locked>> | 98% | 40,886 psi | 66% | 2631 fps | 95% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,601 psi | 44% | 1578 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 45,237 psi | 73% | 2621 fps | 97.9% |
| ReloadSwiss RS 52 | <<locked>> | 80% | 51,242 psi | 82% | 2799 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 41,466 psi | 66% | 2671 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 34,809 psi | 56% | 2493 fps | 96.8% |
| ReloadSwiss RS 70 | 58.2 gr | 80% | 34,200 psi | 55% | 2497 fps | 95.9% |
| Rottweil R 902 | <<locked>> | 80% | 48,660 psi | 78% | 2641 fps | 100% |
| Rottweil R 903 | <<locked>> | 80% | 42,061 psi | 67% | 2575 fps | 99.8% |
| Rottweil R 904 | <<locked>> | 94% | 49,429 psi | 79% | 2717 fps | 95.4% |
| Rottweil R 905 | <<locked>> | 92% | 43,236 psi | 69% | 2657 fps | 95.4% |
| Rottweil R 907 | <<locked>> | 80% | 39,595 psi | 63% | 2500 fps | 95.2% |
| Shooters World Long Rifle | <<locked>> | 80% | 38,464 psi | 62% | 2480 fps | 96.9% |
| Shooters World Match Rifle | <<locked>> | 80% | 52,272 psi | 84% | 2713 fps | 100% |
| Shooters World Precision | <<locked>> | 80% | 46,862 psi | 75% | 2628 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 36,738 psi | 59% | 2461 fps | 95.1% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 43,120 psi | 69% | 2625 fps | 99.6% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 50,531 psi | 81% | 2710 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 51,953 psi | 83% | 2625 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 43,801 psi | 70% | 2497 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 37,811 psi | 61% | 2431 fps | 95.3% |
| SNPE Vectan Tubal 8000 | <<locked>> | 92% | 42,830 psi | 69% | 2651 fps | 95.2% |
| Somchem S335 | <<locked>> | 80% | 51,488 psi | 83% | 2621 fps | 100% |
| Somchem S355 | <<locked>> | 80% | 42,496 psi | 68% | 2575 fps | 99.8% |
| Somchem S365 | <<locked>> | 80% | 31,647 psi | 51% | 2434 fps | 99.1% |
| Somchem S385 | <<locked>> | 90% | 41,017 psi | 66% | 2585 fps | 95.6% |
| Vihtavuori N133 | <<locked>> | 80% | 52,475 psi | 84% | 2608 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 48,776 psi | 78% | 2608 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 48,820 psi | 78% | 2618 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 40,538 psi | 65% | 2510 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 36,506 psi | 59% | 2477 fps | 97.5% |
| Vihtavuori N165 | <<locked>> | 96% | 43,149 psi | 69% | 2615 fps | 95.8% |
| Vihtavuori N540 | <<locked>> | 80% | 47,166 psi | 76% | 2612 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 36,027 psi | 58% | 2477 fps | 97.2% |
| Vihtavuori N555 | <<locked>> | 82% | 29,443 psi | 47% | 2375 fps | 95.8% |
| Vihtavuori N560 | <<locked>> | 98% | 50,430 psi | 81% | 2844 fps | 95.1% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 35,868 psi | 58% | 2451 fps | 99.2% |
| Winchester 760 | <<locked>> | 80% | 37,318 psi | 60% | 2526 fps | 95.1% |
| Winchester StaBALL HD | <<locked>> | 86% | 26,992 psi | 43% | 2382 fps | 96.4% |
| Winchester StaBALL Match | <<locked>> | 80% | 50,444 psi | 81% | 2717 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 94% | 43,482 psi | 70% | 2625 fps | 95.1% |
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 97 powders for .300 H&H Mag. loaded with the .308 | 180gr | Sellier & Bellot HPC. Alliant Reloder-26 delivers the highest muzzle velocity at 2,969 fps; across all powders the maximum-charge window runs from 1,722 fps to 2,969 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 180.0 gr projectile in 0.308" calls for a 1:11.5 twist; slower twists will usually not stabilise this weight. Accurate 3100, Accurate High Country, Alliant Reloder-22 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, Alliant Reloder-26 rank at the top here: for .300 H&H Mag. with the .308 | 180gr | Sellier & Bellot HPC 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.