Load Specifications
Load data in caliber .300 H&H Mag. with .308 | 180gr | Sierra GameKing 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 70, Alliant Reloder-26 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>> | 82% | 54,027 psi | 87% | 2690 fps | 100% |
| Accurate 2700 | <<locked>> | 84% | 55,245 psi | 89% | 2756 fps | 98.6% |
| Accurate 3100ᴾ | <<locked>> | 100% | 52,649 psi | 84% | 2795 fps | 99.4% |
| Accurate 4064 | <<locked>> | 84% | 54,476 psi | 87% | 2746 fps | 100% |
| Accurate 4350 | <<locked>> | 92% | 54,737 psi | 88% | 2844 fps | 100% |
| Accurate High Country | <<locked>> | 98% | 53,505 psi | 86% | 2930 fps | 96.9% |
| ADI AR 2208 | <<locked>> | 86% | 54,578 psi | 88% | 2776 fps | 100% |
| ADI AR 2209 | <<locked>> | 98% | 55,898 psi | 90% | 2887 fps | 98.1% |
| ADI AR 2213ᴾ | <<locked>> | 100% | 53,476 psi | 86% | 2877 fps | 96.4% |
| Alliant Power Pro 2000-MR | <<locked>> | 82% | 53,548 psi | 86% | 2890 fps | 100% |
| Alliant Power Pro Varmint | <<locked>> | 98% | 55,999 psi | 90% | 2887 fps | 98.2% |
| Alliant Reloder- TS 15.5 | <<locked>> | 86% | 55,347 psi | 89% | 2799 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 84% | 55,390 psi | 89% | 2818 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 94% | 55,506 psi | 89% | 2900 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 88% | 53,258 psi | 85% | 2874 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 98% | 55,201 psi | 89% | 2874 fps | 98.1% |
| Alliant Reloder-22ᴾ | <<locked>> | 100% | 52,214 psi | 84% | 2874 fps | 97.7% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 49,255 psi | 79% | 2812 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 43,062 psi | 69% | 2733 fps | 98.7% |
| Alliant Reloder-26 | <<locked>> | 98% | 52,605 psi | 84% | 2946 fps | 100% |
| Bofors RP15ᴾ | <<locked>> | 100% | 47,906 psi | 77% | 2799 fps | 96.7% |
| Bofors RP3 | <<locked>> | 86% | 56,115 psi | 90% | 2815 fps | 100% |
| Bofors RP5ᴾ | <<locked>> | 100% | 52,214 psi | 84% | 2874 fps | 97.7% |
| Bofors RP7 | <<locked>> | 90% | 55,506 psi | 89% | 2799 fps | 98.8% |
| Hodgdon H380 | <<locked>> | 84% | 52,910 psi | 85% | 2776 fps | 99.8% |
| Hodgdon H414 | <<locked>> | 90% | 53,534 psi | 86% | 2844 fps | 99% |
| Hodgdon H4350 | <<locked>> | 88% | 53,447 psi | 86% | 2802 fps | 98% |
| Hodgdon H4831 SCᴾ | <<locked>> | 100% | 56,130 psi | 90% | 2864 fps | 96.3% |
| Hodgdon Hybrid 100V | <<locked>> | 96% | 56,028 psi | 90% | 2828 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 82% | 54,070 psi | 87% | 2812 fps | 100% |
| Hodgdon Superformance | <<locked>> | 90% | 53,403 psi | 86% | 2877 fps | 98.8% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,274 psi | 58% | 1736 fps | 100% |
| Hodgdon VARGET | <<locked>> | 82% | 54,810 psi | 88% | 2776 fps | 100% |
| IMR 4064 | <<locked>> | 84% | 53,969 psi | 87% | 2756 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 82% | 53,214 psi | 85% | 2736 fps | 98.9% |
| IMR 4350 | <<locked>> | 94% | 56,333 psi | 90% | 2828 fps | 98.9% |
| IMR 4451 Enduron | <<locked>> | 88% | 53,737 psi | 86% | 2772 fps | 98.9% |
| IMR 4831 | <<locked>> | 94% | 55,245 psi | 89% | 2838 fps | 100% |
| IMR 4895 | <<locked>> | 82% | 53,374 psi | 86% | 2792 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 98% | 55,405 psi | 89% | 2815 fps | 96.4% |
| IMR 7828 SSCᴾ | <<locked>> | 100% | 51,024 psi | 82% | 2848 fps | 95.9% |
| Lovex S060 | <<locked>> | 82% | 55,637 psi | 89% | 2743 fps | 100% |
| Lovex S062 | <<locked>> | 84% | 54,143 psi | 87% | 2749 fps | 100% |
| Lovex S065 | <<locked>> | 90% | 53,824 psi | 86% | 2769 fps | 99.6% |
| Lovex S070 | <<locked>> | 92% | 54,868 psi | 88% | 2808 fps | 99.2% |
| Lovex S071ᴾ | <<locked>> | 100% | 43,584 psi | 70% | 2644 fps | 98.1% |
| Norma 201 | <<locked>> | 82% | 55,579 psi | 89% | 2762 fps | 100% |
| Norma 202 | <<locked>> | 82% | 56,217 psi | 90% | 2759 fps | 100% |
| Norma 203B | <<locked>> | 84% | 54,679 psi | 88% | 2802 fps | 100% |
| Norma 204 | <<locked>> | 92% | 53,577 psi | 86% | 2828 fps | 97.6% |
| Norma MRPᴾ | <<locked>> | 100% | 55,492 psi | 89% | 2959 fps | 99.3% |
| Norma URP | <<locked>> | 92% | 53,490 psi | 86% | 2828 fps | 100% |
| Ramshot Big Game | <<locked>> | 84% | 55,521 psi | 89% | 2831 fps | 100% |
| Ramshot Grandᴾ | <<locked>> | 100% | 51,126 psi | 82% | 2861 fps | 96.3% |
| Ramshot Hunter | <<locked>> | 94% | 55,927 psi | 90% | 2884 fps | 99.7% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 45,672 psi | 73% | 2736 fps | 96.8% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,014 psi | 59% | 1778 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 84% | 52,881 psi | 85% | 2759 fps | 99.2% |
| ReloadSwiss RS 60 | <<locked>> | 86% | 52,736 psi | 85% | 2867 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 92% | 54,578 psi | 88% | 2867 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 92% | 53,316 psi | 85% | 2897 fps | 99.9% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 41,930 psi | 67% | 2746 fps | 96.6% |
| Rottweil R 902 | <<locked>> | 84% | 56,115 psi | 90% | 2762 fps | 100% |
| Rottweil R 903 | <<locked>> | 88% | 56,202 psi | 90% | 2812 fps | 100% |
| Rottweil R 904 | <<locked>> | 96% | 54,056 psi | 87% | 2802 fps | 96.7% |
| Rottweil R 905 | <<locked>> | 98% | 54,201 psi | 87% | 2858 fps | 98.1% |
| Rottweil R 907 | <<locked>> | 90% | 55,506 psi | 89% | 2799 fps | 98.8% |
| Shooters World Long Rifle | <<locked>> | 90% | 53,824 psi | 86% | 2769 fps | 99.6% |
| Shooters World Precision | <<locked>> | 84% | 54,143 psi | 87% | 2749 fps | 100% |
| Shooters World SW4350 | <<locked>> | 92% | 54,868 psi | 88% | 2808 fps | 99.2% |
| SNPE Vectan SP 11 | <<locked>> | 86% | 54,070 psi | 87% | 2818 fps | 100% |
| SNPE Vectan SP 9 | <<locked>> | 82% | 55,216 psi | 89% | 2789 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 82% | 56,318 psi | 90% | 2694 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 86% | 53,925 psi | 86% | 2654 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 90% | 53,519 psi | 86% | 2723 fps | 98.9% |
| SNPE Vectan Tubal 8000 | <<locked>> | 98% | 53,722 psi | 86% | 2854 fps | 97.9% |
| Somchem S335 | <<locked>> | 82% | 56,072 psi | 90% | 2694 fps | 100% |
| Somchem S355 | <<locked>> | 88% | 56,057 psi | 90% | 2805 fps | 100% |
| Somchem S361 | <<locked>> | 96% | 55,695 psi | 89% | 2795 fps | 96.2% |
| Somchem S365 | <<locked>> | 96% | 56,405 psi | 90% | 2884 fps | 100% |
| Somchem S385 | <<locked>> | 98% | 54,969 psi | 88% | 2838 fps | 98.8% |
| Vihtavuori N135 | <<locked>> | 84% | 56,420 psi | 90% | 2720 fps | 100% |
| Vihtavuori N140 | <<locked>> | 82% | 53,345 psi | 86% | 2694 fps | 100% |
| Vihtavuori N150 | <<locked>> | 88% | 53,954 psi | 87% | 2733 fps | 100% |
| Vihtavuori N160 | <<locked>> | 92% | 55,666 psi | 89% | 2825 fps | 100% |
| Vihtavuori N165ᴾ | <<locked>> | 100% | 50,807 psi | 81% | 2759 fps | 97.8% |
| Vihtavuori N540 | <<locked>> | 84% | 54,882 psi | 88% | 2736 fps | 100% |
| Vihtavuori N550 | <<locked>> | 92% | 54,969 psi | 88% | 2835 fps | 100% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 55,288 psi | 89% | 2890 fps | 100% |
| Vihtavuori N560ᴾ | <<locked>> | 100% | 55,869 psi | 90% | 2946 fps | 96.7% |
| Winchester 6.5 StaBALL | <<locked>> | 92% | 55,492 psi | 89% | 2799 fps | 100% |
| Winchester 760 | <<locked>> | 90% | 53,737 psi | 86% | 2848 fps | 99% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 44,628 psi | 72% | 2867 fps | 100% |
| Winchester StaBALL Match | <<locked>> | 82% | 55,434 psi | 89% | 2799 fps | 100% |
| Winchester Supreme 780ᴾ | <<locked>> | 100% | 55,274 psi | 89% | 2835 fps | 98% |
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% | 50,589 psi | 81% | 2644 fps | 100% |
| Accurate 2700 | <<locked>> | 80% | 48,515 psi | 78% | 2648 fps | 97.5% |
| Accurate 3100 | <<locked>> | 88% | 34,911 psi | 56% | 2464 fps | 95.6% |
| Accurate 4064 | <<locked>> | 80% | 47,950 psi | 77% | 2651 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 36,332 psi | 58% | 2513 fps | 97.8% |
| Accurate High Country | <<locked>> | 94% | 46,557 psi | 75% | 2805 fps | 95.2% |
| ADI AR 2208 | <<locked>> | 80% | 45,353 psi | 73% | 2625 fps | 99.7% |
| ADI AR 2209 | <<locked>> | 90% | 43,105 psi | 69% | 2657 fps | 95.1% |
| ADI AR 2213 | <<locked>> | 98% | 50,038 psi | 80% | 2815 fps | 95.5% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 49,908 psi | 80% | 2831 fps | 100% |
| Alliant Power Pro Varmint | <<locked>> | 90% | 43,062 psi | 69% | 2657 fps | 95.2% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 45,745 psi | 73% | 2648 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 48,820 psi | 78% | 2713 fps | 99.9% |
| Alliant Reloder-16 | <<locked>> | 80% | 35,665 psi | 57% | 2523 fps | 97.9% |
| Alliant Reloder-17 | <<locked>> | 80% | 40,263 psi | 65% | 2648 fps | 99.8% |
| Alliant Reloder-19 | <<locked>> | 90% | 42,569 psi | 68% | 2651 fps | 95.1% |
| Alliant Reloder-22 | <<locked>> | 94% | 42,873 psi | 69% | 2700 fps | 95.4% |
| Alliant Reloder-23 | <<locked>> | 80% | 26,078 psi | 42% | 2280 fps | 95.2% |
| Alliant Reloder-25 | <<locked>> | 92% | 33,460 psi | 54% | 2503 fps | 95.4% |
| Alliant Reloder-26 | 63.4 gr | 84% | 31,850 psi | 51% | 2503 fps | 95.6% |
| Bofors RP15 | <<locked>> | 98% | 44,875 psi | 72% | 2740 fps | 95.8% |
| Bofors RP3 | <<locked>> | 80% | 45,919 psi | 74% | 2657 fps | 100% |
| Bofors RP5 | <<locked>> | 94% | 42,873 psi | 69% | 2700 fps | 95.4% |
| Bofors RP7 | <<locked>> | 80% | 40,625 psi | 65% | 2530 fps | 95.7% |
| Hodgdon H380 | <<locked>> | 80% | 46,514 psi | 75% | 2667 fps | 99.3% |
| Hodgdon H414 | <<locked>> | 80% | 38,377 psi | 62% | 2556 fps | 95.6% |
| Hodgdon H4350 | <<locked>> | 80% | 41,278 psi | 66% | 2579 fps | 95.1% |
| Hodgdon H4831 SC | <<locked>> | 98% | 52,504 psi | 84% | 2805 fps | 95.5% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 33,112 psi | 53% | 2421 fps | 98.4% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 50,502 psi | 81% | 2759 fps | 100% |
| Hodgdon Superformance | 63.8 gr | 82% | 40,059 psi | 64% | 2625 fps | 95.7% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,122 psi | 43% | 1549 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 51,445 psi | 82% | 2723 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 47,718 psi | 77% | 2657 fps | 99.9% |
| IMR 4166 Enduron | <<locked>> | 80% | 50,009 psi | 80% | 2684 fps | 98.4% |
| IMR 4350 | <<locked>> | 82% | 38,653 psi | 62% | 2510 fps | 95% |
| IMR 4451 Enduron | <<locked>> | 80% | 42,076 psi | 67% | 2562 fps | 96.6% |
| IMR 4831 | <<locked>> | 80% | 35,128 psi | 56% | 2467 fps | 97.5% |
| IMR 4895 | <<locked>> | 80% | 50,082 psi | 80% | 2740 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 96% | 52,054 psi | 83% | 2762 fps | 95.6% |
| IMR 7828 SSC | <<locked>> | 98% | 47,747 psi | 77% | 2785 fps | 95% |
| Lovex S060 | <<locked>> | 80% | 52,330 psi | 84% | 2694 fps | 100% |
| Lovex S062 | <<locked>> | 80% | 47,921 psi | 77% | 2654 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 39,537 psi | 63% | 2513 fps | 97.4% |
| Lovex S070 | <<locked>> | 80% | 37,739 psi | 61% | 2490 fps | 95.7% |
| Lovex S071 | <<locked>> | 92% | 33,750 psi | 54% | 2438 fps | 95.1% |
| Norma 201 | <<locked>> | 80% | 52,141 psi | 84% | 2710 fps | 100% |
| Norma 202 | <<locked>> | 80% | 52,765 psi | 85% | 2710 fps | 100% |
| Norma 203B | <<locked>> | 80% | 48,182 psi | 77% | 2700 fps | 100% |
| Norma 204 | <<locked>> | 86% | 43,627 psi | 70% | 2651 fps | 95.2% |
| Norma MRP | <<locked>> | 90% | 39,320 psi | 63% | 2657 fps | 95.8% |
| Norma URP | <<locked>> | 80% | 36,245 psi | 58% | 2507 fps | 97.6% |
| Ramshot Big Game | <<locked>> | 80% | 48,472 psi | 78% | 2723 fps | 100% |
| Ramshot Grand | <<locked>> | 98% | 47,747 psi | 77% | 2799 fps | 95.4% |
| Ramshot Hunter | <<locked>> | 80% | 35,201 psi | 56% | 2493 fps | 95.5% |
| Ramshot Magnum | <<locked>> | 98% | 42,438 psi | 68% | 2674 fps | 95.9% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,688 psi | 44% | 1588 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 46,499 psi | 75% | 2651 fps | 98.3% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 42,801 psi | 69% | 2700 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 36,042 psi | 58% | 2530 fps | 97.4% |
| ReloadSwiss RS 70 | 59.8 gr | 80% | 35,215 psi | 56% | 2533 fps | 96.6% |
| ReloadSwiss RS 76 | <<locked>> | 98% | 39,117 psi | 63% | 2677 fps | 95.4% |
| Rottweil R 902 | <<locked>> | 80% | 49,690 psi | 80% | 2667 fps | 100% |
| Rottweil R 903 | <<locked>> | 80% | 43,265 psi | 69% | 2605 fps | 99.9% |
| Rottweil R 904 | <<locked>> | 92% | 47,558 psi | 76% | 2694 fps | 95.2% |
| Rottweil R 905 | <<locked>> | 90% | 41,771 psi | 67% | 2635 fps | 95.1% |
| Rottweil R 907 | <<locked>> | 80% | 40,625 psi | 65% | 2530 fps | 95.7% |
| Shooters World Long Rifle | <<locked>> | 80% | 39,537 psi | 63% | 2513 fps | 97.4% |
| Shooters World Precision | <<locked>> | 80% | 47,921 psi | 77% | 2654 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 37,739 psi | 61% | 2490 fps | 95.7% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 44,483 psi | 71% | 2657 fps | 99.8% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 51,895 psi | 83% | 2740 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 53,055 psi | 85% | 2648 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 44,802 psi | 72% | 2520 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 38,783 psi | 62% | 2461 fps | 95.8% |
| SNPE Vectan Tubal 8000 | <<locked>> | 92% | 44,208 psi | 71% | 2687 fps | 95.8% |
| Somchem S335 | <<locked>> | 80% | 52,721 psi | 85% | 2648 fps | 100% |
| Somchem S355 | <<locked>> | 80% | 43,656 psi | 70% | 2605 fps | 99.9% |
| Somchem S361 | <<locked>> | 94% | 52,388 psi | 84% | 2743 fps | 95.4% |
| Somchem S365 | <<locked>> | 80% | 32,692 psi | 52% | 2464 fps | 99.4% |
| Somchem S385 | <<locked>> | 88% | 39,653 psi | 64% | 2566 fps | 95.4% |
| Vihtavuori N135 | <<locked>> | 80% | 49,966 psi | 80% | 2631 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 50,082 psi | 80% | 2644 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 41,669 psi | 67% | 2536 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 37,608 psi | 60% | 2507 fps | 98% |
| Vihtavuori N165 | <<locked>> | 94% | 41,727 psi | 67% | 2595 fps | 95.6% |
| Vihtavuori N540 | <<locked>> | 80% | 48,501 psi | 78% | 2641 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 37,231 psi | 60% | 2513 fps | 97.7% |
| Vihtavuori N555 | <<locked>> | 80% | 28,514 psi | 46% | 2352 fps | 95.4% |
| Vihtavuori N560 | <<locked>> | 98% | 52,112 psi | 84% | 2884 fps | 95.8% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 36,840 psi | 59% | 2480 fps | 99.4% |
| Winchester 760 | <<locked>> | 80% | 38,566 psi | 62% | 2562 fps | 95.7% |
| Winchester StaBALL HD | <<locked>> | 84% | 26,223 psi | 42% | 2362 fps | 96% |
| Winchester StaBALL Match | <<locked>> | 80% | 51,851 psi | 83% | 2746 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 94% | 44,846 psi | 72% | 2661 fps | 95.7% |
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 .300 H&H Mag. loaded with the .308 | 180gr | Sierra GameKing. Norma MRP delivers the highest muzzle velocity at 2,959 fps; across all powders the maximum-charge window runs from 1,736 fps to 2,959 fps. Accurate 3100 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 (430 MPa), the top charges use 58–90 %, leaving at least 10 % headroom. The 180.0 gr projectile in 0.308" calls for a 1:12.5 twist; slower twists will usually not stabilise this weight. Accurate 3100, ADI AR 2213, 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-26, Hodgdon Superformance rank at the top here: for .300 H&H Mag. with the .308 | 180gr | Sierra GameKing 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.