Load Specifications
Load data in caliber .300 Win. Mag. with .308 | 172gr | Speer Impact bullet and 96 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.
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% | 53,577 psi | 86% | 2766 fps | 100% |
| Accurate 2700 | <<locked>> | 88% | 56,014 psi | 90% | 2835 fps | 98.5% |
| Accurate 3100ᴾ | <<locked>> | 100% | 51,967 psi | 83% | 2861 fps | 99.2% |
| Accurate 4064 | <<locked>> | 84% | 53,969 psi | 87% | 2818 fps | 100% |
| Accurate 4350 | <<locked>> | 92% | 54,418 psi | 87% | 2920 fps | 100% |
| ADI AR 2206H | <<locked>> | 82% | 56,246 psi | 90% | 2890 fps | 100% |
| ADI AR 2208 | <<locked>> | 86% | 54,056 psi | 87% | 2848 fps | 100% |
| ADI AR 2209 | <<locked>> | 98% | 55,419 psi | 89% | 2959 fps | 97.8% |
| ADI AR 2213ᴾ | <<locked>> | 100% | 52,997 psi | 85% | 2946 fps | 96% |
| Alliant Power Pro 2000-MR | <<locked>> | 82% | 52,997 psi | 85% | 2966 fps | 100% |
| Alliant Reloder- TS 15.5 | <<locked>> | 86% | 54,694 psi | 88% | 2871 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 84% | 55,027 psi | 88% | 2894 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 94% | 54,998 psi | 88% | 2976 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 88% | 52,663 psi | 84% | 2946 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 98% | 54,679 psi | 88% | 2946 fps | 97.8% |
| Alliant Reloder-22ᴾ | <<locked>> | 100% | 51,677 psi | 83% | 2943 fps | 97.4% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 48,921 psi | 78% | 2887 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 42,525 psi | 68% | 2795 fps | 98.4% |
| Alliant Reloder-26ᴾ | <<locked>> | 100% | 56,043 psi | 90% | 3077 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 82% | 56,188 psi | 90% | 2910 fps | 100% |
| Bofors RP15ᴾ | <<locked>> | 100% | 47,369 psi | 76% | 2861 fps | 96.3% |
| Bofors RP3 | <<locked>> | 86% | 55,564 psi | 89% | 2887 fps | 100% |
| Bofors RP5ᴾ | <<locked>> | 100% | 51,677 psi | 83% | 2943 fps | 97.4% |
| Bofors RP7 | <<locked>> | 90% | 54,984 psi | 88% | 2871 fps | 98.6% |
| Hodgdon H380 | <<locked>> | 86% | 56,057 psi | 90% | 2904 fps | 99.9% |
| Hodgdon H414 | <<locked>> | 88% | 54,172 psi | 87% | 2933 fps | 99% |
| Hodgdon H4350 | <<locked>> | 92% | 54,737 psi | 88% | 2904 fps | 98% |
| Hodgdon H4831 SCᴾ | <<locked>> | 100% | 55,651 psi | 89% | 2933 fps | 96% |
| Hodgdon Hybrid 100V | <<locked>> | 96% | 55,390 psi | 89% | 2900 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 84% | 53,867 psi | 86% | 2890 fps | 100% |
| Hodgdon Superformance | <<locked>> | 90% | 52,982 psi | 85% | 2949 fps | 98.6% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,289 psi | 58% | 1791 fps | 100% |
| Hodgdon VARGET | <<locked>> | 84% | 53,621 psi | 86% | 2838 fps | 100% |
| IMR 3031 | <<locked>> | 84% | 56,231 psi | 90% | 2861 fps | 100% |
| IMR 4064 | <<locked>> | 86% | 53,069 psi | 85% | 2825 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 88% | 55,288 psi | 89% | 2851 fps | 99% |
| IMR 4350 | <<locked>> | 94% | 55,796 psi | 89% | 2900 fps | 98.7% |
| IMR 4451 Enduron | <<locked>> | 88% | 53,287 psi | 85% | 2844 fps | 98.7% |
| IMR 4831 | <<locked>> | 98% | 55,593 psi | 89% | 2923 fps | 100% |
| IMR 4895 | <<locked>> | 82% | 52,866 psi | 85% | 2867 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 98% | 54,911 psi | 88% | 2887 fps | 96% |
| IMR 7828 SSCᴾ | <<locked>> | 100% | 54,520 psi | 87% | 2986 fps | 96.5% |
| Lovex S060 | <<locked>> | 82% | 55,085 psi | 88% | 2815 fps | 100% |
| Lovex S062 | <<locked>> | 84% | 53,664 psi | 86% | 2825 fps | 100% |
| Lovex S065 | <<locked>> | 90% | 53,330 psi | 86% | 2841 fps | 99.5% |
| Lovex S070 | <<locked>> | 92% | 54,389 psi | 87% | 2881 fps | 99% |
| Lovex S071ᴾ | <<locked>> | 100% | 43,163 psi | 69% | 2710 fps | 97.8% |
| Norma 201 | <<locked>> | 82% | 55,158 psi | 88% | 2838 fps | 100% |
| Norma 202 | <<locked>> | 82% | 55,767 psi | 89% | 2835 fps | 100% |
| Norma 203B | <<locked>> | 84% | 54,317 psi | 87% | 2877 fps | 100% |
| Norma 204 | <<locked>> | 92% | 52,924 psi | 85% | 2894 fps | 97.3% |
| Norma MRPᴾ | <<locked>> | 100% | 55,027 psi | 88% | 3031 fps | 99.1% |
| Norma URP | <<locked>> | 92% | 53,040 psi | 85% | 2900 fps | 99.9% |
| Ramshot Big Game | <<locked>> | 84% | 54,911 psi | 88% | 2904 fps | 100% |
| Ramshot Grand | <<locked>> | 98% | 54,331 psi | 87% | 2992 fps | 96.8% |
| Ramshot Hunter | <<locked>> | 94% | 55,390 psi | 89% | 2956 fps | 99.6% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 50,894 psi | 82% | 2907 fps | 97.9% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 36,985 psi | 59% | 1837 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 86% | 55,898 psi | 90% | 2887 fps | 99.4% |
| ReloadSwiss RS 52 | <<locked>> | 82% | 55,999 psi | 90% | 2963 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 88% | 55,985 psi | 90% | 2995 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 92% | 54,056 psi | 87% | 2940 fps | 99.9% |
| ReloadSwiss RS 70 | <<locked>> | 92% | 52,721 psi | 85% | 2969 fps | 99.9% |
| Rottweil R 902 | <<locked>> | 84% | 55,680 psi | 89% | 2838 fps | 100% |
| Rottweil R 903 | <<locked>> | 88% | 55,651 psi | 89% | 2884 fps | 100% |
| Rottweil R 904 | <<locked>> | 96% | 53,722 psi | 86% | 2874 fps | 96.4% |
| Rottweil R 905 | <<locked>> | 98% | 53,650 psi | 86% | 2930 fps | 97.8% |
| Rottweil R 907 | <<locked>> | 90% | 54,984 psi | 88% | 2871 fps | 98.6% |
| Shooters World Long Rifle | <<locked>> | 90% | 53,330 psi | 86% | 2841 fps | 99.5% |
| Shooters World Precision | <<locked>> | 84% | 53,664 psi | 86% | 2825 fps | 100% |
| Shooters World SW4350 | <<locked>> | 92% | 54,389 psi | 87% | 2881 fps | 99% |
| SNPE Vectan SP 11 | <<locked>> | 86% | 53,490 psi | 86% | 2887 fps | 100% |
| SNPE Vectan SP 9 | <<locked>> | 82% | 54,853 psi | 88% | 2867 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 82% | 55,854 psi | 90% | 2766 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 86% | 53,490 psi | 86% | 2726 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 90% | 53,113 psi | 85% | 2795 fps | 98.7% |
| SNPE Vectan Tubal 8000 | <<locked>> | 98% | 53,171 psi | 85% | 2923 fps | 97.7% |
| Somchem S335 | <<locked>> | 82% | 55,709 psi | 89% | 2766 fps | 100% |
| Somchem S355 | <<locked>> | 88% | 55,608 psi | 89% | 2881 fps | 100% |
| Somchem S361 | <<locked>> | 96% | 55,463 psi | 89% | 2867 fps | 95.9% |
| Somchem S365 | <<locked>> | 96% | 55,898 psi | 90% | 2959 fps | 100% |
| Somchem S385 | <<locked>> | 98% | 54,636 psi | 88% | 2910 fps | 98.6% |
| Unknown powder | <<locked>> | 90% | 53,693 psi | 86% | 2907 fps | 99.8% |
| Vihtavuori N133 | <<locked>> | 84% | 55,854 psi | 90% | 2746 fps | 100% |
| Vihtavuori N135 | <<locked>> | 84% | 56,028 psi | 90% | 2799 fps | 100% |
| Vihtavuori N140 | <<locked>> | 84% | 55,550 psi | 89% | 2805 fps | 100% |
| Vihtavuori N150 | <<locked>> | 92% | 53,737 psi | 86% | 2812 fps | 100% |
| Vihtavuori N160 | <<locked>> | 90% | 54,288 psi | 87% | 2881 fps | 99.9% |
| Vihtavuori N165ᴾ | <<locked>> | 100% | 48,370 psi | 78% | 2792 fps | 97.1% |
| Vihtavuori N540 | <<locked>> | 84% | 55,129 psi | 88% | 2828 fps | 100% |
| Vihtavuori N550 | <<locked>> | 90% | 54,534 psi | 87% | 2923 fps | 99.9% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 54,607 psi | 88% | 2963 fps | 100% |
| Winchester 6.5 StaBALL | <<locked>> | 92% | 54,926 psi | 88% | 2867 fps | 100% |
| Winchester 760 | <<locked>> | 88% | 54,172 psi | 87% | 2933 fps | 99% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 44,106 psi | 71% | 2933 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 96% | 52,678 psi | 84% | 2871 fps | 97.3% |
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% | 50,053 psi | 80% | 2713 fps | 100% |
| Accurate 2700 | <<locked>> | 80% | 43,192 psi | 69% | 2615 fps | 96% |
| Accurate 3100 | <<locked>> | 88% | 34,606 psi | 55% | 2526 fps | 95.2% |
| Accurate 4064 | <<locked>> | 80% | 47,355 psi | 76% | 2720 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 35,955 psi | 58% | 2575 fps | 97.4% |
| ADI AR 2206H | <<locked>> | 80% | 52,881 psi | 85% | 2841 fps | 100% |
| ADI AR 2208 | <<locked>> | 80% | 44,933 psi | 72% | 2694 fps | 99.5% |
| ADI AR 2209 | <<locked>> | 92% | 45,542 psi | 73% | 2782 fps | 95.6% |
| ADI AR 2213 | <<locked>> | 98% | 49,748 psi | 80% | 2887 fps | 95.2% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 49,472 psi | 79% | 2904 fps | 99.9% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 45,411 psi | 73% | 2720 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 48,428 psi | 78% | 2785 fps | 99.9% |
| Alliant Reloder-16 | 56.2 gr | 80% | 35,259 psi | 57% | 2585 fps | 97.5% |
| Alliant Reloder-17 | <<locked>> | 80% | 39,769 psi | 64% | 2713 fps | 99.7% |
| Alliant Reloder-19 | <<locked>> | 92% | 45,150 psi | 72% | 2776 fps | 95.7% |
| Alliant Reloder-22 | <<locked>> | 96% | 45,281 psi | 73% | 2825 fps | 95.9% |
| Alliant Reloder-23 | <<locked>> | 82% | 27,543 psi | 44% | 2392 fps | 95.8% |
| Alliant Reloder-25 | <<locked>> | 94% | 35,215 psi | 56% | 2618 fps | 95.9% |
| Alliant Reloder-26 | 65.1 gr | 84% | 31,401 psi | 50% | 2559 fps | 95.1% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 52,678 psi | 84% | 2858 fps | 99.9% |
| Bofors RP15 | <<locked>> | 98% | 44,425 psi | 71% | 2805 fps | 95.4% |
| Bofors RP3 | <<locked>> | 80% | 45,513 psi | 73% | 2726 fps | 100% |
| Bofors RP5 | <<locked>> | 96% | 45,281 psi | 73% | 2825 fps | 95.9% |
| Bofors RP7 | <<locked>> | 80% | 40,190 psi | 64% | 2595 fps | 95.3% |
| Hodgdon H380 | <<locked>> | 80% | 46,064 psi | 74% | 2740 fps | 99.1% |
| Hodgdon H414 | <<locked>> | 80% | 41,191 psi | 66% | 2694 fps | 96.3% |
| Hodgdon H4350 | <<locked>> | 84% | 42,786 psi | 69% | 2684 fps | 95.3% |
| Hodgdon H4831 SC | <<locked>> | 98% | 52,199 psi | 84% | 2877 fps | 95.2% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 32,735 psi | 52% | 2480 fps | 98.1% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 47,311 psi | 76% | 2785 fps | 100% |
| Hodgdon Superformance | <<locked>> | 82% | 39,711 psi | 64% | 2690 fps | 95.3% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,035 psi | 43% | 1601 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 47,369 psi | 76% | 2736 fps | 100% |
| IMR 3031 | <<locked>> | 80% | 49,588 psi | 80% | 2766 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 44,164 psi | 71% | 2671 fps | 99.6% |
| IMR 4166 Enduron | <<locked>> | 80% | 43,497 psi | 70% | 2638 fps | 96.9% |
| IMR 4350 | <<locked>> | 84% | 40,886 psi | 66% | 2631 fps | 95.5% |
| IMR 4451 Enduron | <<locked>> | 80% | 41,626 psi | 67% | 2628 fps | 96.2% |
| IMR 4831 | <<locked>> | 80% | 31,546 psi | 51% | 2451 fps | 95.9% |
| IMR 4895 | <<locked>> | 80% | 49,661 psi | 80% | 2815 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 96% | 51,706 psi | 83% | 2831 fps | 95.3% |
| IMR 7828 SSC | <<locked>> | 98% | 50,850 psi | 82% | 2920 fps | 95.6% |
| Lovex S060 | <<locked>> | 80% | 51,837 psi | 83% | 2766 fps | 100% |
| Lovex S062 | <<locked>> | 80% | 47,413 psi | 76% | 2723 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 39,102 psi | 63% | 2575 fps | 97% |
| Lovex S070 | <<locked>> | 80% | 37,434 psi | 60% | 2556 fps | 95.3% |
| Lovex S071 | <<locked>> | 94% | 35,621 psi | 57% | 2549 fps | 95.6% |
| Norma 201 | <<locked>> | 80% | 51,619 psi | 83% | 2785 fps | 100% |
| Norma 202 | <<locked>> | 80% | 52,446 psi | 84% | 2785 fps | 100% |
| Norma 203B | <<locked>> | 80% | 47,776 psi | 77% | 2772 fps | 100% |
| Norma 204 | <<locked>> | 88% | 46,180 psi | 74% | 2776 fps | 95.7% |
| Norma MRP | <<locked>> | 90% | 38,812 psi | 62% | 2717 fps | 95.3% |
| Norma URP | <<locked>> | 80% | 35,911 psi | 58% | 2572 fps | 97.3% |
| Ramshot Big Game | <<locked>> | 80% | 48,095 psi | 77% | 2795 fps | 99.9% |
| Ramshot Grand | <<locked>> | 96% | 50,299 psi | 81% | 2920 fps | 95.8% |
| Ramshot Hunter | <<locked>> | 80% | 34,824 psi | 56% | 2552 fps | 95% |
| Ramshot Magnum | <<locked>> | 96% | 43,598 psi | 70% | 2769 fps | 96% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,543 psi | 44% | 1640 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 46,006 psi | 74% | 2720 fps | 98% |
| ReloadSwiss RS 52 | <<locked>> | 80% | 52,286 psi | 84% | 2904 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 42,279 psi | 68% | 2769 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 35,752 psi | 57% | 2592 fps | 97% |
| ReloadSwiss RS 70 | 61.5 gr | 80% | 34,896 psi | 56% | 2595 fps | 96.2% |
| Rottweil R 902 | <<locked>> | 80% | 49,211 psi | 79% | 2736 fps | 100% |
| Rottweil R 903 | <<locked>> | 80% | 42,946 psi | 69% | 2674 fps | 99.9% |
| Rottweil R 904 | <<locked>> | 94% | 50,227 psi | 81% | 2815 fps | 95.6% |
| Rottweil R 905 | <<locked>> | 92% | 43,947 psi | 70% | 2756 fps | 95.5% |
| Rottweil R 907 | <<locked>> | 80% | 40,190 psi | 64% | 2595 fps | 95.3% |
| Shooters World Long Rifle | <<locked>> | 80% | 39,102 psi | 63% | 2575 fps | 97% |
| Shooters World Precision | <<locked>> | 80% | 47,413 psi | 76% | 2723 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 37,434 psi | 60% | 2556 fps | 95.3% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 43,976 psi | 71% | 2726 fps | 99.7% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 51,387 psi | 82% | 2812 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 52,634 psi | 84% | 2720 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 44,425 psi | 71% | 2589 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 38,290 psi | 61% | 2520 fps | 95.4% |
| SNPE Vectan Tubal 8000 | <<locked>> | 92% | 43,540 psi | 70% | 2749 fps | 95.3% |
| Somchem S335 | <<locked>> | 80% | 52,214 psi | 84% | 2717 fps | 100% |
| Somchem S355 | <<locked>> | 80% | 43,178 psi | 69% | 2671 fps | 99.8% |
| Somchem S361 | <<locked>> | 94% | 51,764 psi | 83% | 2808 fps | 95% |
| Somchem S365 | <<locked>> | 80% | 32,372 psi | 52% | 2530 fps | 99.2% |
| Somchem S385 | <<locked>> | 88% | 39,349 psi | 63% | 2628 fps | 95% |
| Unknown powder | <<locked>> | 80% | 38,682 psi | 62% | 2628 fps | 97.5% |
| Vihtavuori N133 | <<locked>> | 80% | 49,719 psi | 80% | 2661 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 49,545 psi | 79% | 2707 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 49,081 psi | 79% | 2710 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 37,057 psi | 59% | 2520 fps | 99.8% |
| Vihtavuori N160 | <<locked>> | 80% | 38,798 psi | 62% | 2602 fps | 98% |
| Vihtavuori N165 | <<locked>> | 96% | 42,525 psi | 68% | 2684 fps | 95.6% |
| Vihtavuori N540 | <<locked>> | 80% | 48,617 psi | 78% | 2730 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 39,407 psi | 63% | 2648 fps | 98.1% |
| Vihtavuori N555 | <<locked>> | 80% | 28,224 psi | 45% | 2411 fps | 95% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 36,521 psi | 59% | 2546 fps | 99.3% |
| Winchester 760 | <<locked>> | 80% | 41,191 psi | 66% | 2694 fps | 96.3% |
| Winchester StaBALL HD | <<locked>> | 84% | 25,933 psi | 42% | 2415 fps | 95.3% |
| Winchester Supreme 780 | <<locked>> | 92% | 45,701 psi | 73% | 2749 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 96 powders for .300 Win. Mag. loaded with the .308 | 172gr | Speer Impact. Alliant Reloder-26 delivers the highest muzzle velocity at 3,077 fps; across all powders the maximum-charge window runs from 1,791 fps to 3,077 fps. Accurate 3100 gives the best case fill at 100 %, and 96 of the 96 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 172.0 gr projectile in 0.308" calls for a 1:11.5 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-16, Alliant Reloder-26 rank at the top here: for .300 Win. Mag. with the .308 | 172gr | Speer Impact 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.