Load Specifications
Load data in caliber .300 H&H Mag. with .308 | 180gr | Hornady SP 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% | 54,172 psi | 87% | 2690 fps | 100% |
| Accurate 2700 | <<locked>> | 84% | 55,535 psi | 89% | 2759 fps | 98.6% |
| Accurate 3100ᴾ | <<locked>> | 100% | 52,895 psi | 85% | 2799 fps | 99.4% |
| Accurate 4064 | <<locked>> | 84% | 54,607 psi | 88% | 2746 fps | 100% |
| Accurate 4350 | <<locked>> | 92% | 55,042 psi | 88% | 2848 fps | 100% |
| Accurate High Country | <<locked>> | 98% | 53,998 psi | 87% | 2936 fps | 97.1% |
| ADI AR 2208 | <<locked>> | 86% | 54,636 psi | 88% | 2776 fps | 100% |
| ADI AR 2209 | <<locked>> | 98% | 56,173 psi | 90% | 2890 fps | 98.2% |
| ADI AR 2213ᴾ | <<locked>> | 100% | 53,911 psi | 86% | 2884 fps | 96.5% |
| Alliant Power Pro 2000-MR | <<locked>> | 82% | 53,882 psi | 86% | 2897 fps | 100% |
| Alliant Power Pro Varmint | <<locked>> | 98% | 56,217 psi | 90% | 2887 fps | 98.2% |
| Alliant Power Pro Varmint | <<locked>> | 98% | 56,217 psi | 90% | 2887 fps | 98.2% |
| Alliant Power Pro Varmint | <<locked>> | 98% | 56,217 psi | 90% | 2887 fps | 98.2% |
| Alliant Reloder- TS 15.5 | <<locked>> | 86% | 55,405 psi | 89% | 2799 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 84% | 55,666 psi | 89% | 2822 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 94% | 55,811 psi | 89% | 2904 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 88% | 53,548 psi | 86% | 2877 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 98% | 55,448 psi | 89% | 2881 fps | 98.1% |
| Alliant Reloder-22ᴾ | <<locked>> | 100% | 52,678 psi | 84% | 2881 fps | 97.8% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 49,748 psi | 80% | 2818 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 43,250 psi | 69% | 2736 fps | 98.8% |
| Alliant Reloder-26 | <<locked>> | 98% | 53,113 psi | 85% | 2949 fps | 100% |
| Bofors RP15ᴾ | <<locked>> | 100% | 48,124 psi | 77% | 2799 fps | 96.7% |
| Bofors RP3 | <<locked>> | 86% | 56,376 psi | 90% | 2818 fps | 100% |
| Bofors RP5ᴾ | <<locked>> | 100% | 52,678 psi | 84% | 2881 fps | 97.8% |
| Bofors RP7 | <<locked>> | 90% | 55,782 psi | 89% | 2802 fps | 98.8% |
| Hodgdon H380 | <<locked>> | 84% | 53,156 psi | 85% | 2779 fps | 99.9% |
| Hodgdon H414 | <<locked>> | 90% | 53,809 psi | 86% | 2848 fps | 99.1% |
| Hodgdon H4350 | <<locked>> | 88% | 53,664 psi | 86% | 2805 fps | 98% |
| Hodgdon H4831 | <<locked>> | 98% | 53,998 psi | 87% | 2828 fps | 95.9% |
| Hodgdon Hybrid 100V | <<locked>> | 96% | 56,318 psi | 90% | 2831 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 82% | 54,404 psi | 87% | 2815 fps | 100% |
| Hodgdon Superformance | <<locked>> | 90% | 53,664 psi | 86% | 2877 fps | 98.8% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,463 psi | 58% | 1739 fps | 100% |
| Hodgdon VARGET | <<locked>> | 82% | 55,129 psi | 88% | 2779 fps | 100% |
| IMR 4064 | <<locked>> | 84% | 54,288 psi | 87% | 2762 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 82% | 53,476 psi | 86% | 2743 fps | 98.9% |
| IMR 4350 | <<locked>> | 92% | 53,171 psi | 85% | 2779 fps | 98.5% |
| IMR 4451 Enduron | <<locked>> | 88% | 53,983 psi | 87% | 2776 fps | 98.9% |
| IMR 4831 | <<locked>> | 94% | 55,521 psi | 89% | 2841 fps | 100% |
| IMR 4895 | <<locked>> | 82% | 53,664 psi | 86% | 2795 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 98% | 55,637 psi | 89% | 2818 fps | 96.4% |
| IMR 7828 SSCᴾ | <<locked>> | 100% | 51,198 psi | 82% | 2851 fps | 96% |
| Lovex S060 | <<locked>> | 82% | 55,724 psi | 89% | 2746 fps | 100% |
| Lovex S062 | <<locked>> | 84% | 54,433 psi | 87% | 2753 fps | 100% |
| Lovex S065 | <<locked>> | 90% | 54,099 psi | 87% | 2776 fps | 99.7% |
| Lovex S070 | <<locked>> | 92% | 55,129 psi | 88% | 2812 fps | 99.3% |
| Lovex S071ᴾ | <<locked>> | 100% | 44,048 psi | 71% | 2651 fps | 98.2% |
| Norma 201 | <<locked>> | 82% | 55,608 psi | 89% | 2762 fps | 100% |
| Norma 203B | <<locked>> | 84% | 54,955 psi | 88% | 2808 fps | 100% |
| Norma 204 | <<locked>> | 92% | 53,809 psi | 86% | 2831 fps | 97.6% |
| Norma MRPᴾ | <<locked>> | 100% | 55,970 psi | 90% | 2963 fps | 99.3% |
| Norma URP | <<locked>> | 92% | 53,780 psi | 86% | 2831 fps | 100% |
| Ramshot Big Game | <<locked>> | 84% | 55,825 psi | 90% | 2835 fps | 100% |
| Ramshot Grandᴾ | <<locked>> | 100% | 51,314 psi | 82% | 2864 fps | 96.4% |
| Ramshot Hunter | <<locked>> | 94% | 56,231 psi | 90% | 2887 fps | 99.7% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 45,832 psi | 73% | 2740 fps | 96.9% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,014 psi | 59% | 1778 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 84% | 53,171 psi | 85% | 2762 fps | 99.2% |
| ReloadSwiss RS 60 | <<locked>> | 86% | 53,040 psi | 85% | 2871 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 92% | 54,868 psi | 88% | 2871 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 92% | 53,534 psi | 86% | 2897 fps | 99.9% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 42,279 psi | 68% | 2753 fps | 96.8% |
| Rottweil R 902 | <<locked>> | 82% | 52,997 psi | 85% | 2717 fps | 100% |
| Rottweil R 903 | <<locked>> | 86% | 52,982 psi | 85% | 2762 fps | 100% |
| Rottweil R 904 | <<locked>> | 96% | 54,346 psi | 87% | 2808 fps | 96.8% |
| Rottweil R 905 | <<locked>> | 98% | 54,708 psi | 88% | 2867 fps | 98.1% |
| Rottweil R 907 | <<locked>> | 90% | 55,782 psi | 89% | 2802 fps | 98.8% |
| Shooters World Long Rifle | <<locked>> | 90% | 54,099 psi | 87% | 2776 fps | 99.7% |
| Shooters World Precision | <<locked>> | 84% | 54,433 psi | 87% | 2753 fps | 100% |
| Shooters World SW4350 | <<locked>> | 92% | 55,129 psi | 88% | 2812 fps | 99.3% |
| SNPE Vectan SP 11 | <<locked>> | 86% | 54,360 psi | 87% | 2818 fps | 100% |
| SNPE Vectan SP 9 | <<locked>> | 82% | 55,506 psi | 89% | 2795 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 86% | 53,998 psi | 87% | 2654 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 90% | 53,664 psi | 86% | 2726 fps | 98.9% |
| SNPE Vectan Tubal 8000 | <<locked>> | 98% | 54,230 psi | 87% | 2861 fps | 98% |
| Somchem S335 | <<locked>> | 82% | 56,144 psi | 90% | 2694 fps | 100% |
| Somchem S355 | <<locked>> | 88% | 56,376 psi | 90% | 2808 fps | 100% |
| Somchem S361 | <<locked>> | 96% | 56,173 psi | 90% | 2802 fps | 96.3% |
| Somchem S365 | <<locked>> | 94% | 53,026 psi | 85% | 2838 fps | 100% |
| Somchem S385 | <<locked>> | 98% | 55,216 psi | 89% | 2841 fps | 98.8% |
| Vihtavuori N135 | <<locked>> | 82% | 53,447 psi | 86% | 2680 fps | 100% |
| Vihtavuori N140 | <<locked>> | 82% | 53,664 psi | 86% | 2697 fps | 100% |
| Vihtavuori N150 | <<locked>> | 88% | 54,259 psi | 87% | 2736 fps | 100% |
| Vihtavuori N160 | <<locked>> | 92% | 55,912 psi | 90% | 2828 fps | 100% |
| Vihtavuori N165ᴾ | <<locked>> | 100% | 51,068 psi | 82% | 2762 fps | 97.8% |
| Vihtavuori N540 | <<locked>> | 84% | 55,187 psi | 88% | 2736 fps | 100% |
| Vihtavuori N550 | <<locked>> | 92% | 55,216 psi | 89% | 2838 fps | 100% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 55,535 psi | 89% | 2894 fps | 100% |
| Vihtavuori N560ᴾ | <<locked>> | 100% | 56,304 psi | 90% | 2953 fps | 96.8% |
| Winchester 6.5 StaBALL | <<locked>> | 92% | 55,724 psi | 89% | 2799 fps | 100% |
| Winchester 760 | <<locked>> | 90% | 54,012 psi | 87% | 2851 fps | 99.1% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 44,831 psi | 72% | 2871 fps | 100% |
| Winchester StaBALL Match | <<locked>> | 82% | 55,477 psi | 89% | 2799 fps | 100% |
| Winchester Supreme 780ᴾ | <<locked>> | 100% | 55,477 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% | 50,995 psi | 82% | 2648 fps | 100% |
| Accurate 2700 | <<locked>> | 80% | 48,573 psi | 78% | 2648 fps | 97.5% |
| Accurate 3100 | <<locked>> | 88% | 35,114 psi | 56% | 2467 fps | 95.6% |
| Accurate 4064 | <<locked>> | 80% | 48,283 psi | 77% | 2654 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 36,622 psi | 59% | 2516 fps | 97.9% |
| Accurate High Country | <<locked>> | 94% | 46,789 psi | 75% | 2808 fps | 95.3% |
| ADI AR 2208 | <<locked>> | 80% | 45,455 psi | 73% | 2625 fps | 99.7% |
| ADI AR 2209 | <<locked>> | 90% | 43,337 psi | 69% | 2664 fps | 95.2% |
| ADI AR 2213 | <<locked>> | 98% | 50,212 psi | 81% | 2818 fps | 95.6% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 50,212 psi | 81% | 2838 fps | 100% |
| Alliant Power Pro Varmint | <<locked>> | 90% | 43,308 psi | 69% | 2661 fps | 95.3% |
| Alliant Power Pro Varmint | <<locked>> | 90% | 43,308 psi | 69% | 2661 fps | 95.3% |
| Alliant Power Pro Varmint | <<locked>> | 90% | 43,308 psi | 69% | 2661 fps | 95.3% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 46,021 psi | 74% | 2651 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 49,124 psi | 79% | 2717 fps | 99.9% |
| Alliant Reloder-16 | <<locked>> | 80% | 35,752 psi | 57% | 2523 fps | 97.9% |
| Alliant Reloder-17 | <<locked>> | 80% | 40,335 psi | 65% | 2648 fps | 99.8% |
| Alliant Reloder-19 | <<locked>> | 90% | 42,801 psi | 69% | 2654 fps | 95.2% |
| Alliant Reloder-22 | <<locked>> | 94% | 43,091 psi | 69% | 2707 fps | 95.5% |
| Alliant Reloder-23 | <<locked>> | 80% | 26,266 psi | 42% | 2283 fps | 95.4% |
| Alliant Reloder-25 | <<locked>> | 92% | 33,634 psi | 54% | 2507 fps | 95.5% |
| Alliant Reloder-26 | 63.6 gr | 84% | 31,879 psi | 51% | 2503 fps | 95.7% |
| Bofors RP15 | <<locked>> | 96% | 42,279 psi | 68% | 2687 fps | 95% |
| Bofors RP3 | <<locked>> | 80% | 46,209 psi | 74% | 2661 fps | 100% |
| Bofors RP5 | <<locked>> | 94% | 43,091 psi | 69% | 2707 fps | 95.5% |
| Bofors RP7 | <<locked>> | 80% | 40,683 psi | 65% | 2533 fps | 95.7% |
| Hodgdon H380 | <<locked>> | 80% | 46,601 psi | 75% | 2671 fps | 99.3% |
| Hodgdon H414 | <<locked>> | 80% | 38,638 psi | 62% | 2562 fps | 95.7% |
| Hodgdon H4350 | <<locked>> | 80% | 41,539 psi | 67% | 2582 fps | 95.1% |
| Hodgdon H4831 | <<locked>> | 96% | 50,328 psi | 81% | 2769 fps | 95% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 33,402 psi | 54% | 2425 fps | 98.5% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 50,792 psi | 81% | 2762 fps | 100% |
| Hodgdon Superformance | 64.1 gr | 82% | 40,277 psi | 65% | 2628 fps | 95.8% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,166 psi | 44% | 1552 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 51,735 psi | 83% | 2730 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 47,790 psi | 77% | 2657 fps | 99.9% |
| IMR 4166 Enduron | <<locked>> | 80% | 50,024 psi | 80% | 2684 fps | 98.4% |
| IMR 4350 | <<locked>> | 82% | 38,885 psi | 62% | 2513 fps | 95.1% |
| IMR 4451 Enduron | <<locked>> | 80% | 42,148 psi | 68% | 2562 fps | 96.6% |
| IMR 4831 | <<locked>> | 80% | 35,215 psi | 56% | 2470 fps | 97.5% |
| IMR 4895 | <<locked>> | 80% | 50,386 psi | 81% | 2746 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 96% | 52,286 psi | 84% | 2766 fps | 95.7% |
| IMR 7828 SSC | <<locked>> | 98% | 47,993 psi | 77% | 2792 fps | 95.1% |
| Lovex S060 | <<locked>> | 80% | 52,620 psi | 84% | 2700 fps | 100% |
| Lovex S062 | <<locked>> | 80% | 48,196 psi | 77% | 2657 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 39,798 psi | 64% | 2516 fps | 97.4% |
| Lovex S070 | <<locked>> | 80% | 37,971 psi | 61% | 2493 fps | 95.7% |
| Lovex S071 | <<locked>> | 92% | 33,953 psi | 54% | 2441 fps | 95.2% |
| Norma 201 | <<locked>> | 80% | 52,489 psi | 84% | 2717 fps | 100% |
| Norma 203B | <<locked>> | 80% | 48,472 psi | 78% | 2703 fps | 100% |
| Norma 204 | <<locked>> | 86% | 43,859 psi | 70% | 2654 fps | 95.3% |
| Norma MRP | <<locked>> | 90% | 39,537 psi | 63% | 2657 fps | 95.8% |
| Norma URP | <<locked>> | 80% | 36,492 psi | 59% | 2513 fps | 97.7% |
| Ramshot Big Game | <<locked>> | 80% | 48,791 psi | 78% | 2726 fps | 100% |
| Ramshot Grand | <<locked>> | 98% | 47,950 psi | 77% | 2802 fps | 95.5% |
| Ramshot Hunter | <<locked>> | 80% | 35,273 psi | 57% | 2493 fps | 95.5% |
| Ramshot Magnum | <<locked>> | 98% | 42,598 psi | 68% | 2677 fps | 96% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,731 psi | 44% | 1591 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 46,731 psi | 75% | 2654 fps | 98.3% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 42,873 psi | 69% | 2703 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 36,303 psi | 58% | 2533 fps | 97.4% |
| ReloadSwiss RS 70 | 60.1 gr | 80% | 35,418 psi | 57% | 2536 fps | 96.7% |
| ReloadSwiss RS 76 | <<locked>> | 98% | 39,247 psi | 63% | 2680 fps | 95.5% |
| Rottweil R 902 | <<locked>> | 80% | 49,980 psi | 80% | 2671 fps | 100% |
| Rottweil R 903 | <<locked>> | 80% | 43,598 psi | 70% | 2608 fps | 99.9% |
| Rottweil R 904 | <<locked>> | 92% | 47,776 psi | 77% | 2697 fps | 95.2% |
| Rottweil R 905 | <<locked>> | 90% | 41,974 psi | 67% | 2641 fps | 95.2% |
| Rottweil R 907 | <<locked>> | 80% | 40,683 psi | 65% | 2533 fps | 95.7% |
| Shooters World Long Rifle | <<locked>> | 80% | 39,798 psi | 64% | 2516 fps | 97.4% |
| Shooters World Precision | <<locked>> | 80% | 48,196 psi | 77% | 2657 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 37,971 psi | 61% | 2493 fps | 95.7% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 44,570 psi | 71% | 2657 fps | 99.8% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 51,938 psi | 83% | 2740 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 44,889 psi | 72% | 2520 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 38,841 psi | 62% | 2461 fps | 95.9% |
| SNPE Vectan Tubal 8000 | <<locked>> | 90% | 41,568 psi | 67% | 2635 fps | 95% |
| Somchem S335 | <<locked>> | 80% | 53,026 psi | 85% | 2648 fps | 100% |
| Somchem S355 | <<locked>> | 80% | 43,976 psi | 71% | 2608 fps | 99.9% |
| Somchem S361 | <<locked>> | 94% | 52,547 psi | 84% | 2746 fps | 95.5% |
| Somchem S365 | <<locked>> | 80% | 32,967 psi | 53% | 2470 fps | 99.4% |
| Somchem S385 | <<locked>> | 88% | 39,900 psi | 64% | 2569 fps | 95.5% |
| Vihtavuori N135 | <<locked>> | 80% | 50,053 psi | 80% | 2635 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 50,357 psi | 81% | 2648 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 41,945 psi | 67% | 2539 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 37,855 psi | 61% | 2513 fps | 98% |
| Vihtavuori N165 | <<locked>> | 94% | 41,945 psi | 67% | 2602 fps | 95.6% |
| Vihtavuori N540 | <<locked>> | 80% | 48,544 psi | 78% | 2641 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 37,304 psi | 60% | 2513 fps | 97.7% |
| Vihtavuori N555 | <<locked>> | 80% | 28,747 psi | 46% | 2359 fps | 95.5% |
| Vihtavuori N560 | <<locked>> | 96% | 49,023 psi | 79% | 2828 fps | 95% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 37,043 psi | 59% | 2484 fps | 99.5% |
| Winchester 760 | <<locked>> | 80% | 38,638 psi | 62% | 2562 fps | 95.7% |
| Winchester StaBALL HD | <<locked>> | 84% | 26,266 psi | 42% | 2362 fps | 96.1% |
| Winchester StaBALL Match | <<locked>> | 80% | 52,141 psi | 84% | 2749 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 94% | 45,078 psi | 72% | 2664 fps | 95.8% |
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 | Hornady SP. Norma MRP delivers the highest muzzle velocity at 2,963 fps; across all powders the maximum-charge window runs from 1,739 fps to 2,963 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 1:14.0 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 | Hornady SP 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.