Load Specifications
Load data in caliber .300 Win. Mag. with .308 | 178gr | Hornady ELD-X 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% | 54,911 psi | 88% | 2736 fps | 100% |
| Accurate 2700 | <<locked>> | 84% | 56,159 psi | 90% | 2808 fps | 98.8% |
| Accurate 3100ᴾ | <<locked>> | 100% | 53,838 psi | 86% | 2848 fps | 99.6% |
| Accurate 4064 | <<locked>> | 84% | 55,288 psi | 89% | 2789 fps | 100% |
| Accurate 4350 | <<locked>> | 92% | 56,014 psi | 90% | 2897 fps | 100% |
| Accurate High Country | <<locked>> | 98% | 54,868 psi | 88% | 2989 fps | 97.4% |
| Accurate MAGPROᴾ | <<locked>> | 100% | 56,028 psi | 90% | 2989 fps | 96.3% |
| ADI AR 2208 | <<locked>> | 86% | 55,463 psi | 89% | 2825 fps | 100% |
| ADI AR 2209 | <<locked>> | 96% | 53,301 psi | 85% | 2884 fps | 97.8% |
| ADI AR 2213ᴾ | <<locked>> | 100% | 54,621 psi | 88% | 2933 fps | 96.9% |
| Alliant Power Pro 2000-MR | <<locked>> | 82% | 54,665 psi | 88% | 2946 fps | 100% |
| Alliant Power Pro Varmint | <<locked>> | 96% | 53,432 psi | 86% | 2881 fps | 97.9% |
| Alliant Reloder- TS 15.5 | <<locked>> | 86% | 56,246 psi | 90% | 2844 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 82% | 52,953 psi | 85% | 2815 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 92% | 53,214 psi | 85% | 2900 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 88% | 54,447 psi | 87% | 2927 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 98% | 56,318 psi | 90% | 2930 fps | 98.4% |
| Alliant Reloder-22ᴾ | <<locked>> | 100% | 53,490 psi | 86% | 2930 fps | 98.1% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 50,444 psi | 81% | 2864 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 43,947 psi | 70% | 2789 fps | 99.1% |
| Alliant Reloder-26 | <<locked>> | 98% | 54,157 psi | 87% | 3005 fps | 100% |
| Bofors RP15ᴾ | <<locked>> | 100% | 48,950 psi | 78% | 2851 fps | 97.1% |
| Bofors RP3 | <<locked>> | 84% | 53,476 psi | 86% | 2812 fps | 100% |
| Bofors RP5ᴾ | <<locked>> | 100% | 53,490 psi | 86% | 2930 fps | 98.1% |
| Bofors RP7 | <<locked>> | 88% | 53,084 psi | 85% | 2799 fps | 98.6% |
| Hodgdon H380 | <<locked>> | 84% | 53,940 psi | 86% | 2828 fps | 99.9% |
| Hodgdon H414 | <<locked>> | 90% | 54,650 psi | 88% | 2897 fps | 99.2% |
| Hodgdon H4350 | <<locked>> | 88% | 54,331 psi | 87% | 2854 fps | 98.3% |
| Hodgdon H4831 | <<locked>> | 98% | 54,781 psi | 88% | 2881 fps | 96.3% |
| Hodgdon H4831 SC | <<locked>> | 98% | 53,563 psi | 86% | 2858 fps | 96% |
| Hodgdon Hybrid 100V | <<locked>> | 94% | 53,635 psi | 86% | 2828 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 82% | 55,172 psi | 88% | 2864 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 43,062 psi | 69% | 2815 fps | 96.2% |
| Hodgdon Superformance | <<locked>> | 90% | 54,810 psi | 88% | 2933 fps | 99.1% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,347 psi | 58% | 1765 fps | 100% |
| Hodgdon VARGET | <<locked>> | 82% | 55,738 psi | 89% | 2825 fps | 100% |
| IMR 4064 | <<locked>> | 84% | 54,940 psi | 88% | 2808 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 82% | 54,027 psi | 87% | 2789 fps | 99.1% |
| IMR 4350 | <<locked>> | 92% | 53,969 psi | 87% | 2831 fps | 98.8% |
| IMR 4451 Enduron | <<locked>> | 88% | 54,636 psi | 88% | 2825 fps | 99.1% |
| IMR 4831 | <<locked>> | 94% | 56,347 psi | 90% | 2887 fps | 100% |
| IMR 4895 | <<locked>> | 82% | 54,302 psi | 87% | 2844 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 98% | 56,434 psi | 90% | 2871 fps | 96.8% |
| IMR 7828 SSCᴾ | <<locked>> | 100% | 51,982 psi | 83% | 2904 fps | 96.4% |
| Lovex S060 | <<locked>> | 82% | 56,376 psi | 90% | 2792 fps | 100% |
| Lovex S062 | <<locked>> | 84% | 55,071 psi | 88% | 2799 fps | 100% |
| Lovex S065 | <<locked>> | 90% | 54,737 psi | 88% | 2822 fps | 99.8% |
| Lovex S070 | <<locked>> | 92% | 55,941 psi | 90% | 2861 fps | 99.4% |
| Lovex S071ᴾ | <<locked>> | 100% | 44,759 psi | 72% | 2700 fps | 98.4% |
| Norma 201 | <<locked>> | 82% | 56,318 psi | 90% | 2808 fps | 100% |
| Norma 203B | <<locked>> | 84% | 55,825 psi | 90% | 2854 fps | 100% |
| Norma 204 | <<locked>> | 92% | 54,549 psi | 87% | 2881 fps | 97.9% |
| Norma MRP | <<locked>> | 98% | 52,924 psi | 85% | 2956 fps | 99.1% |
| Norma URP | <<locked>> | 92% | 54,679 psi | 88% | 2884 fps | 100% |
| Ramshot Big Game | <<locked>> | 82% | 52,910 psi | 85% | 2828 fps | 100% |
| Ramshot Grandᴾ | <<locked>> | 100% | 52,286 psi | 84% | 2920 fps | 96.9% |
| Ramshot Hunter | <<locked>> | 92% | 53,476 psi | 86% | 2884 fps | 99.6% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 46,673 psi | 75% | 2795 fps | 97.4% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,086 psi | 59% | 1808 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 84% | 53,824 psi | 86% | 2812 fps | 99.4% |
| ReloadSwiss RS 60 | <<locked>> | 86% | 53,737 psi | 86% | 2917 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 92% | 55,912 psi | 90% | 2923 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 92% | 54,447 psi | 87% | 2953 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 42,946 psi | 69% | 2808 fps | 97.3% |
| Rottweil R 902 | <<locked>> | 82% | 53,722 psi | 86% | 2762 fps | 100% |
| Rottweil R 903 | <<locked>> | 86% | 53,563 psi | 86% | 2808 fps | 100% |
| Rottweil R 904 | <<locked>> | 96% | 55,013 psi | 88% | 2854 fps | 97.1% |
| Rottweil R 905 | <<locked>> | 98% | 55,434 psi | 89% | 2913 fps | 98.4% |
| Rottweil R 907 | <<locked>> | 88% | 53,084 psi | 85% | 2799 fps | 98.6% |
| Shooters World Long Rifle | <<locked>> | 90% | 54,737 psi | 88% | 2822 fps | 99.8% |
| Shooters World Precision | <<locked>> | 84% | 55,071 psi | 88% | 2799 fps | 100% |
| Shooters World SW4350 | <<locked>> | 92% | 55,941 psi | 90% | 2861 fps | 99.4% |
| SNPE Vectan SP 11 | <<locked>> | 86% | 55,085 psi | 88% | 2867 fps | 100% |
| SNPE Vectan SP 9 | <<locked>> | 82% | 56,014 psi | 90% | 2838 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 86% | 54,621 psi | 88% | 2697 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 90% | 54,273 psi | 87% | 2772 fps | 99.1% |
| SNPE Vectan Tubal 8000 | <<locked>> | 98% | 54,940 psi | 88% | 2910 fps | 98.3% |
| Somchem S355 | <<locked>> | 86% | 53,737 psi | 86% | 2805 fps | 100% |
| Somchem S361 | <<locked>> | 94% | 53,272 psi | 85% | 2795 fps | 95.9% |
| Somchem S365 | <<locked>> | 94% | 53,954 psi | 87% | 2884 fps | 100% |
| Somchem S385 | <<locked>> | 98% | 56,115 psi | 90% | 2890 fps | 99% |
| Vihtavuori N135 | <<locked>> | 82% | 54,012 psi | 87% | 2723 fps | 100% |
| Vihtavuori N140 | <<locked>> | 82% | 54,302 psi | 87% | 2740 fps | 100% |
| Vihtavuori N150 | <<locked>> | 88% | 54,984 psi | 88% | 2782 fps | 100% |
| Vihtavuori N160 | <<locked>> | 90% | 53,359 psi | 86% | 2828 fps | 100% |
| Vihtavuori N165ᴾ | <<locked>> | 100% | 51,837 psi | 83% | 2808 fps | 98.1% |
| Vihtavuori N540 | <<locked>> | 84% | 55,912 psi | 90% | 2782 fps | 100% |
| Vihtavuori N550 | <<locked>> | 92% | 56,028 psi | 90% | 2884 fps | 100% |
| Vihtavuori N555 | <<locked>> | 98% | 53,055 psi | 85% | 2890 fps | 100% |
| Vihtavuori N560 | <<locked>> | 98% | 53,330 psi | 86% | 2943 fps | 96.3% |
| Winchester 6.5 StaBALL | <<locked>> | 90% | 52,707 psi | 85% | 2792 fps | 100% |
| Winchester 760 | <<locked>> | 90% | 54,839 psi | 88% | 2900 fps | 99.3% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 45,716 psi | 73% | 2923 fps | 100% |
| Winchester StaBALL Match | <<locked>> | 82% | 56,246 psi | 90% | 2844 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 98% | 52,649 psi | 84% | 2828 fps | 97.7% |
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% | 51,503 psi | 83% | 2690 fps | 100% |
| Accurate 2700 | <<locked>> | 80% | 49,298 psi | 79% | 2697 fps | 97.8% |
| Accurate 3100 | <<locked>> | 86% | 33,446 psi | 54% | 2461 fps | 95.2% |
| Accurate 4064 | <<locked>> | 80% | 48,805 psi | 78% | 2697 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 37,260 psi | 60% | 2566 fps | 98.2% |
| Accurate High Country | <<locked>> | 94% | 47,703 psi | 76% | 2861 fps | 95.7% |
| Accurate MAGPRO | <<locked>> | 98% | 51,996 psi | 83% | 2923 fps | 95.3% |
| ADI AR 2208 | <<locked>> | 80% | 46,108 psi | 74% | 2671 fps | 99.8% |
| ADI AR 2209 | <<locked>> | 90% | 43,859 psi | 70% | 2710 fps | 95.6% |
| ADI AR 2213 | <<locked>> | 96% | 47,834 psi | 77% | 2812 fps | 95.1% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 50,807 psi | 81% | 2884 fps | 100% |
| Alliant Power Pro Varmint | <<locked>> | 90% | 44,048 psi | 71% | 2713 fps | 95.7% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 46,514 psi | 75% | 2697 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 49,763 psi | 80% | 2766 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 80% | 36,332 psi | 58% | 2572 fps | 98.2% |
| Alliant Reloder-17 | <<locked>> | 80% | 41,089 psi | 66% | 2697 fps | 99.9% |
| Alliant Reloder-19 | <<locked>> | 90% | 43,540 psi | 70% | 2707 fps | 95.7% |
| Alliant Reloder-22 | <<locked>> | 92% | 41,060 psi | 66% | 2697 fps | 95% |
| Alliant Reloder-23 | <<locked>> | 80% | 26,600 psi | 43% | 2326 fps | 95.8% |
| Alliant Reloder-25 | <<locked>> | 92% | 34,171 psi | 55% | 2556 fps | 96% |
| Alliant Reloder-26 | 63.7 gr | 82% | 30,400 psi | 49% | 2493 fps | 95.1% |
| Bofors RP15 | <<locked>> | 96% | 43,163 psi | 69% | 2740 fps | 95.5% |
| Bofors RP3 | <<locked>> | 80% | 46,876 psi | 75% | 2707 fps | 100% |
| Bofors RP5 | <<locked>> | 92% | 41,060 psi | 66% | 2697 fps | 95% |
| Bofors RP7 | <<locked>> | 80% | 41,278 psi | 66% | 2579 fps | 96.1% |
| Hodgdon H380 | <<locked>> | 80% | 47,181 psi | 76% | 2717 fps | 99.5% |
| Hodgdon H414 | <<locked>> | 80% | 39,175 psi | 63% | 2608 fps | 96.1% |
| Hodgdon H4350 | <<locked>> | 80% | 42,105 psi | 68% | 2631 fps | 95.5% |
| Hodgdon H4831 | <<locked>> | 96% | 51,155 psi | 82% | 2818 fps | 95.4% |
| Hodgdon H4831 SC | <<locked>> | 96% | 50,227 psi | 81% | 2802 fps | 95.2% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 33,837 psi | 54% | 2470 fps | 98.8% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 51,416 psi | 82% | 2805 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 98% | 40,451 psi | 65% | 2753 fps | 95.1% |
| Hodgdon Superformance | 64 gr | 80% | 37,985 psi | 61% | 2612 fps | 95.2% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,267 psi | 44% | 1578 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 52,417 psi | 84% | 2776 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 48,501 psi | 78% | 2703 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 80% | 50,604 psi | 81% | 2730 fps | 98.6% |
| IMR 4350 | <<locked>> | 82% | 39,378 psi | 63% | 2559 fps | 95.5% |
| IMR 4451 Enduron | <<locked>> | 80% | 42,699 psi | 68% | 2608 fps | 97% |
| IMR 4831 | <<locked>> | 80% | 35,795 psi | 57% | 2516 fps | 97.8% |
| IMR 4895 | <<locked>> | 80% | 51,068 psi | 82% | 2792 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 94% | 49,763 psi | 80% | 2759 fps | 95.3% |
| IMR 7828 SSC | <<locked>> | 98% | 48,762 psi | 78% | 2844 fps | 95.6% |
| Lovex S060 | <<locked>> | 80% | 53,055 psi | 85% | 2743 fps | 100% |
| Lovex S062 | <<locked>> | 80% | 48,718 psi | 78% | 2700 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 40,205 psi | 64% | 2559 fps | 97.7% |
| Lovex S070 | <<locked>> | 80% | 38,363 psi | 62% | 2539 fps | 96.1% |
| Lovex S071 | <<locked>> | 92% | 34,563 psi | 55% | 2487 fps | 95.6% |
| Norma 201 | <<locked>> | 80% | 52,997 psi | 85% | 2759 fps | 100% |
| Norma 203B | <<locked>> | 80% | 49,139 psi | 79% | 2753 fps | 100% |
| Norma 204 | <<locked>> | 86% | 44,454 psi | 71% | 2700 fps | 95.7% |
| Norma MRP | <<locked>> | 88% | 37,536 psi | 60% | 2648 fps | 95.3% |
| Norma URP | <<locked>> | 80% | 36,927 psi | 59% | 2556 fps | 98% |
| Ramshot Big Game | <<locked>> | 80% | 49,284 psi | 79% | 2769 fps | 100% |
| Ramshot Grand | <<locked>> | 98% | 48,675 psi | 78% | 2854 fps | 95.9% |
| Ramshot Hunter | <<locked>> | 80% | 35,926 psi | 58% | 2543 fps | 96% |
| Ramshot Magnum | <<locked>> | 96% | 40,422 psi | 65% | 2667 fps | 95.5% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,644 psi | 44% | 1614 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 47,268 psi | 76% | 2700 fps | 98.6% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 43,642 psi | 70% | 2753 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 36,869 psi | 59% | 2579 fps | 97.8% |
| ReloadSwiss RS 70 | 61.5 gr | 80% | 35,824 psi | 57% | 2582 fps | 97.1% |
| ReloadSwiss RS 76 | <<locked>> | 98% | 39,958 psi | 64% | 2736 fps | 96.2% |
| Rottweil R 902 | <<locked>> | 80% | 50,517 psi | 81% | 2713 fps | 100% |
| Rottweil R 903 | <<locked>> | 80% | 44,063 psi | 71% | 2651 fps | 100% |
| Rottweil R 904 | <<locked>> | 92% | 48,573 psi | 78% | 2746 fps | 95.6% |
| Rottweil R 905 | <<locked>> | 90% | 42,583 psi | 68% | 2687 fps | 95.6% |
| Rottweil R 907 | <<locked>> | 80% | 41,278 psi | 66% | 2579 fps | 96.1% |
| Shooters World Long Rifle | <<locked>> | 80% | 40,205 psi | 64% | 2559 fps | 97.7% |
| Shooters World Precision | <<locked>> | 80% | 48,718 psi | 78% | 2700 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 38,363 psi | 62% | 2539 fps | 96.1% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 45,353 psi | 73% | 2710 fps | 99.9% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 52,765 psi | 85% | 2789 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 45,397 psi | 73% | 2562 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 39,363 psi | 63% | 2507 fps | 96.2% |
| SNPE Vectan Tubal 8000 | <<locked>> | 90% | 42,192 psi | 68% | 2680 fps | 95.4% |
| Somchem S355 | <<locked>> | 80% | 44,411 psi | 71% | 2651 fps | 100% |
| Somchem S361 | <<locked>> | 92% | 49,951 psi | 80% | 2740 fps | 95.1% |
| Somchem S365 | <<locked>> | 80% | 33,547 psi | 54% | 2516 fps | 99.6% |
| Somchem S385 | <<locked>> | 86% | 38,000 psi | 61% | 2559 fps | 95% |
| Vihtavuori N135 | <<locked>> | 80% | 50,662 psi | 81% | 2677 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 50,821 psi | 81% | 2690 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 42,380 psi | 68% | 2582 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 38,450 psi | 62% | 2559 fps | 98.3% |
| Vihtavuori N165 | <<locked>> | 92% | 39,769 psi | 64% | 2589 fps | 95.1% |
| Vihtavuori N540 | <<locked>> | 80% | 49,124 psi | 79% | 2684 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 37,826 psi | 61% | 2559 fps | 98% |
| Vihtavuori N555 | <<locked>> | 80% | 29,182 psi | 47% | 2402 fps | 95.9% |
| Vihtavuori N560 | <<locked>> | 96% | 49,806 psi | 80% | 2881 fps | 95.5% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 37,608 psi | 60% | 2530 fps | 99.6% |
| Winchester 760 | <<locked>> | 80% | 39,175 psi | 63% | 2608 fps | 96.1% |
| Winchester StaBALL HD | <<locked>> | 82% | 25,005 psi | 40% | 2349 fps | 95.3% |
| Winchester StaBALL Match | <<locked>> | 80% | 52,663 psi | 84% | 2795 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 92% | 42,612 psi | 68% | 2651 fps | 95.3% |
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 Win. Mag. loaded with the .308 | 178gr | Hornady ELD-X. Alliant Reloder-26 delivers the highest muzzle velocity at 3,005 fps; across all powders the maximum-charge window runs from 1,765 fps to 3,005 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 178.0 gr projectile in 0.308" calls for a 1:11.5 twist; slower twists will usually not stabilise this weight. Accurate 3100, Accurate MAGPRO, ADI AR 2213 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 Win. Mag. with the .308 | 178gr | Hornady ELD-X 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.