Load Specifications
Load data in caliber .300 WSM with .308 | 155gr | Norma Kalahari bullet and 99 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Alliant Power Pro 2000-MR, Hodgdon Superformance and Alliant Reloder-17.
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 2015 | <<locked>> | 84% | 55,303 psi | 87% | 2881 fps | 100% |
| Accurate 2460 | <<locked>> | 82% | 57,595 psi | 90% | 2963 fps | 100% |
| Accurate 2495 | <<locked>> | 90% | 57,725 psi | 90% | 2953 fps | 100% |
| Accurate 2520 | <<locked>> | 84% | 54,273 psi | 85% | 2959 fps | 100% |
| Accurate 2700 | <<locked>> | 92% | 54,418 psi | 85% | 2904 fps | 96.5% |
| Accurate 4064 | <<locked>> | 92% | 57,638 psi | 90% | 3002 fps | 100% |
| Accurate 4350 | <<locked>> | 98% | 53,867 psi | 84% | 3031 fps | 99.4% |
| ADI AR 2206H | <<locked>> | 86% | 54,563 psi | 86% | 2986 fps | 99.9% |
| ADI AR 2208 | <<locked>> | 92% | 55,637 psi | 87% | 2982 fps | 99.7% |
| ADI Benchmark 8208 | <<locked>> | 86% | 57,014 psi | 89% | 2989 fps | 100% |
| Alliant AR-Comp | <<locked>> | 84% | 54,201 psi | 85% | 2910 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 88% | 54,143 psi | 85% | 3104 fps | 99.7% |
| Alliant Reloder- TS 15.5 | <<locked>> | 92% | 55,724 psi | 87% | 3009 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 90% | 56,130 psi | 88% | 3028 fps | 99.8% |
| Alliant Reloder-16ᴾ | <<locked>> | 100% | 55,071 psi | 86% | 3094 fps | 99.7% |
| Alliant Reloder-17 | <<locked>> | 96% | 56,550 psi | 89% | 3133 fps | 100% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 39,450 psi | 62% | 2812 fps | 98.4% |
| Alliant Reloder-26ᴾ | <<locked>> | 100% | 44,179 psi | 69% | 2976 fps | 97.7% |
| Baschieri & Pellagri 107 | <<locked>> | 86% | 54,317 psi | 85% | 2999 fps | 99.5% |
| Bofors RP3 | <<locked>> | 92% | 56,260 psi | 88% | 3022 fps | 100% |
| Bofors RP7 | <<locked>> | 96% | 56,260 psi | 88% | 2989 fps | 97.2% |
| Hodgdon Benchmark | <<locked>> | 84% | 55,187 psi | 86% | 2917 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 86% | 56,565 psi | 89% | 3018 fps | 100% |
| Hodgdon CFE223 | <<locked>> | 82% | 54,665 psi | 86% | 3061 fps | 99.7% |
| Hodgdon H322 | <<locked>> | 84% | 56,898 psi | 89% | 2969 fps | 100% |
| Hodgdon H380 | <<locked>> | 92% | 57,377 psi | 90% | 3038 fps | 99.4% |
| Hodgdon H414 | <<locked>> | 94% | 54,911 psi | 86% | 3054 fps | 97.6% |
| Hodgdon H4350 | <<locked>> | 98% | 55,361 psi | 87% | 3012 fps | 96.3% |
| Hodgdon H4895 | <<locked>> | 86% | 55,158 psi | 86% | 2999 fps | 100% |
| Hodgdon Hybrid 100Vᴾ | <<locked>> | 100% | 51,416 psi | 81% | 2963 fps | 99.9% |
| Hodgdon LEVERevolution | <<locked>> | 90% | 54,520 psi | 85% | 3028 fps | 100% |
| Hodgdon Superformance | <<locked>> | 96% | 53,838 psi | 84% | 3061 fps | 97% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 35,418 psi | 56% | 1837 fps | 100% |
| Hodgdon VARGET | <<locked>> | 90% | 55,230 psi | 87% | 2979 fps | 100% |
| IMR 3031 | <<locked>> | 90% | 56,855 psi | 89% | 3005 fps | 100% |
| IMR 4064 | <<locked>> | 94% | 57,522 psi | 90% | 3002 fps | 99.9% |
| IMR 4166 Enduron | <<locked>> | 94% | 56,927 psi | 89% | 2972 fps | 97.8% |
| IMR 4350ᴾ | <<locked>> | 100% | 56,637 psi | 89% | 3015 fps | 97.3% |
| IMR 4451 Enduron | <<locked>> | 94% | 54,694 psi | 86% | 2966 fps | 97.3% |
| IMR 4831ᴾ | <<locked>> | 100% | 48,559 psi | 76% | 2927 fps | 98.8% |
| IMR 4895 | <<locked>> | 90% | 57,580 psi | 90% | 3061 fps | 100% |
| IMR 8208 XBR | <<locked>> | 86% | 57,014 psi | 89% | 2989 fps | 100% |
| Lovex D073.5 | <<locked>> | 82% | 57,450 psi | 90% | 2972 fps | 100% |
| Lovex D073.6 | <<locked>> | 86% | 54,273 psi | 85% | 2959 fps | 100% |
| Lovex S060 | <<locked>> | 88% | 57,406 psi | 90% | 2959 fps | 100% |
| Lovex S062 | <<locked>> | 90% | 54,853 psi | 86% | 2963 fps | 100% |
| Lovex S065 | <<locked>> | 98% | 57,537 psi | 90% | 3015 fps | 98.9% |
| Lovex S070 | <<locked>> | 98% | 55,013 psi | 86% | 2992 fps | 97.7% |
| Norma 201 | <<locked>> | 88% | 56,608 psi | 89% | 2979 fps | 100% |
| Norma 202 | <<locked>> | 88% | 57,406 psi | 90% | 2982 fps | 100% |
| Norma 203B | <<locked>> | 90% | 55,303 psi | 87% | 3015 fps | 99.9% |
| Norma 204ᴾ | <<locked>> | 100% | 57,450 psi | 90% | 3068 fps | 96.1% |
| Norma URPᴾ | <<locked>> | 100% | 56,449 psi | 88% | 3074 fps | 99.6% |
| Ramshot Big Game | <<locked>> | 90% | 56,014 psi | 88% | 3041 fps | 99.9% |
| Ramshot Hunterᴾ | <<locked>> | 100% | 55,347 psi | 87% | 3068 fps | 98.4% |
| Ramshot TAC | <<locked>> | 86% | 57,319 psi | 90% | 3005 fps | 99% |
| Ramshot Wild Boar | <<locked>> | 86% | 57,101 psi | 89% | 3028 fps | 100% |
| Ramshot X-Terminator | <<locked>> | 82% | 54,375 psi | 85% | 2933 fps | 99.8% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 36,042 psi | 56% | 1883 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 82% | 56,391 psi | 88% | 2966 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 92% | 57,580 psi | 90% | 3015 fps | 98.4% |
| ReloadSwiss RS 52 | <<locked>> | 88% | 56,753 psi | 89% | 3100 fps | 99.8% |
| ReloadSwiss RS 60 | <<locked>> | 94% | 56,246 psi | 88% | 3133 fps | 100% |
| ReloadSwiss RS 62ᴾ | <<locked>> | 100% | 57,450 psi | 90% | 3114 fps | 99.6% |
| ReloadSwiss RS 70ᴾ | <<locked>> | 100% | 57,188 psi | 90% | 3143 fps | 99.4% |
| Rottweil R 901 | <<locked>> | 86% | 57,537 psi | 90% | 2959 fps | 100% |
| Rottweil R 902 | <<locked>> | 90% | 57,232 psi | 90% | 2979 fps | 100% |
| Rottweil R 903 | <<locked>> | 94% | 56,115 psi | 88% | 3012 fps | 100% |
| Rottweil R 907 | <<locked>> | 96% | 56,260 psi | 88% | 2989 fps | 97.2% |
| Shooters World Long Rifle | <<locked>> | 98% | 57,537 psi | 90% | 3015 fps | 98.9% |
| Shooters World Match Rifle | <<locked>> | 86% | 54,273 psi | 85% | 2959 fps | 100% |
| Shooters World Precision | <<locked>> | 90% | 54,853 psi | 86% | 2963 fps | 100% |
| Shooters World SW4350 | <<locked>> | 98% | 55,013 psi | 86% | 2992 fps | 97.7% |
| SNPE Vectan SP 11 | <<locked>> | 92% | 54,462 psi | 85% | 3025 fps | 99.9% |
| SNPE Vectan SP 7 | <<locked>> | 86% | 55,796 psi | 87% | 2982 fps | 99.2% |
| SNPE Vectan SP 9 | <<locked>> | 88% | 56,463 psi | 88% | 3005 fps | 99.9% |
| SNPE Vectan Tubal 3000 | <<locked>> | 86% | 54,824 psi | 86% | 2871 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 92% | 55,143 psi | 86% | 2867 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 96% | 54,592 psi | 86% | 2913 fps | 97.4% |
| Somchem S321 | <<locked>> | 82% | 54,795 psi | 86% | 2966 fps | 100% |
| Somchem S335 | <<locked>> | 88% | 57,493 psi | 90% | 2910 fps | 100% |
| Somchem S341 | <<locked>> | 86% | 55,405 psi | 87% | 2972 fps | 99.9% |
| Somchem S355 | <<locked>> | 94% | 56,304 psi | 88% | 3012 fps | 100% |
| Somchem S365ᴾ | <<locked>> | 100% | 50,923 psi | 80% | 3022 fps | 100% |
| Unknown powder | <<locked>> | 98% | 57,653 psi | 90% | 3084 fps | 99.3% |
| Vihtavuori N130 | <<locked>> | 84% | 56,666 psi | 89% | 2864 fps | 100% |
| Vihtavuori N133 | <<locked>> | 90% | 57,740 psi | 90% | 2894 fps | 100% |
| Vihtavuori N135 | <<locked>> | 90% | 56,971 psi | 89% | 2940 fps | 100% |
| Vihtavuori N140 | <<locked>> | 90% | 57,087 psi | 89% | 2949 fps | 100% |
| Vihtavuori N150ᴾ | <<locked>> | 100% | 57,667 psi | 90% | 2989 fps | 100% |
| Vihtavuori N160 | <<locked>> | 96% | 54,592 psi | 86% | 2999 fps | 99.3% |
| Vihtavuori N530 | <<locked>> | 84% | 56,811 psi | 89% | 2995 fps | 100% |
| Vihtavuori N540 | <<locked>> | 90% | 56,840 psi | 89% | 2979 fps | 100% |
| Vihtavuori N550 | <<locked>> | 96% | 54,940 psi | 86% | 3048 fps | 99.3% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 43,395 psi | 68% | 2894 fps | 98.4% |
| Winchester 6.5 StaBALL | <<locked>> | 98% | 56,072 psi | 88% | 2995 fps | 100% |
| Winchester 748 | <<locked>> | 82% | 54,549 psi | 85% | 2992 fps | 100% |
| Winchester 760 | <<locked>> | 94% | 54,911 psi | 86% | 3054 fps | 97.6% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 35,375 psi | 55% | 2805 fps | 98.2% |
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 2015 | <<locked>> | 80% | 48,965 psi | 77% | 2789 fps | 100% |
| Accurate 2460 | <<locked>> | 80% | 53,853 psi | 84% | 2910 fps | 100% |
| Accurate 2495 | <<locked>> | 80% | 41,785 psi | 65% | 2710 fps | 100% |
| Accurate 2520 | <<locked>> | 80% | 47,268 psi | 74% | 2848 fps | 100% |
| Accurate 2700 | <<locked>> | 88% | 47,674 psi | 75% | 2789 fps | 95% |
| Accurate 4064 | <<locked>> | 80% | 39,508 psi | 62% | 2700 fps | 100% |
| Accurate 4350 | <<locked>> | 86% | 35,592 psi | 56% | 2677 fps | 95.4% |
| ADI AR 2206H | <<locked>> | 80% | 45,121 psi | 71% | 2818 fps | 99% |
| ADI AR 2208 | <<locked>> | 80% | 38,464 psi | 60% | 2661 fps | 97% |
| ADI Benchmark 8208 | <<locked>> | 80% | 47,181 psi | 74% | 2828 fps | 99.8% |
| Alliant AR-Comp | <<locked>> | 80% | 47,645 psi | 75% | 2815 fps | 100% |
| Alliant Power Pro 2000-MR | 56.5 gr | 80% | 41,162 psi | 65% | 2848 fps | 97.6% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 37,971 psi | 60% | 2680 fps | 98.3% |
| Alliant Reloder-15 | <<locked>> | 80% | 40,814 psi | 64% | 2749 fps | 97.8% |
| Alliant Reloder-16 | <<locked>> | 86% | 35,679 psi | 56% | 2687 fps | 95.5% |
| Alliant Reloder-17 | 55.6 gr | 80% | 32,866 psi | 52% | 2641 fps | 96.3% |
| Alliant Reloder-23 | <<locked>> | 92% | 30,792 psi | 48% | 2582 fps | 95.1% |
| Alliant Reloder-26 | <<locked>> | 96% | 38,464 psi | 60% | 2841 fps | 95.8% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 44,295 psi | 69% | 2818 fps | 98% |
| Bofors RP3 | <<locked>> | 80% | 37,768 psi | 59% | 2687 fps | 98.4% |
| Bofors RP7 | <<locked>> | 90% | 46,659 psi | 73% | 2822 fps | 95% |
| Hodgdon Benchmark | <<locked>> | 80% | 48,892 psi | 77% | 2815 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 80% | 46,224 psi | 72% | 2851 fps | 99.9% |
| Hodgdon CFE223 | <<locked>> | 80% | 51,024 psi | 80% | 3002 fps | 99.4% |
| Hodgdon H322 | <<locked>> | 80% | 50,241 psi | 79% | 2867 fps | 100% |
| Hodgdon H380 | <<locked>> | 80% | 38,638 psi | 61% | 2690 fps | 95.8% |
| Hodgdon H414 | <<locked>> | 88% | 44,715 psi | 70% | 2871 fps | 95.2% |
| Hodgdon H4350 | <<locked>> | 96% | 52,025 psi | 82% | 2956 fps | 95.6% |
| Hodgdon H4895 | <<locked>> | 80% | 45,513 psi | 71% | 2828 fps | 99.4% |
| Hodgdon Hybrid 100V | <<locked>> | 84% | 30,690 psi | 48% | 2523 fps | 95.4% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 39,247 psi | 62% | 2749 fps | 98.7% |
| Hodgdon Superformance | 67.6 gr | 92% | 46,702 psi | 73% | 2930 fps | 95.1% |
| Hodgdon TrailBoss | <<locked>> | 80% | 26,484 psi | 42% | 1644 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 40,538 psi | 64% | 2713 fps | 98.5% |
| IMR 3031 | <<locked>> | 80% | 41,597 psi | 65% | 2759 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 37,652 psi | 59% | 2638 fps | 97% |
| IMR 4166 Enduron | <<locked>> | 86% | 45,005 psi | 71% | 2762 fps | 95.2% |
| IMR 4350 | <<locked>> | 94% | 47,036 psi | 74% | 2851 fps | 95.1% |
| IMR 4451 Enduron | <<locked>> | 88% | 45,571 psi | 71% | 2802 fps | 95.2% |
| IMR 4831 | <<locked>> | 90% | 35,244 psi | 55% | 2651 fps | 95.4% |
| IMR 4895 | <<locked>> | 80% | 41,800 psi | 66% | 2779 fps | 98.5% |
| IMR 8208 XBR | <<locked>> | 80% | 47,181 psi | 74% | 2828 fps | 99.8% |
| Lovex D073.5 | <<locked>> | 80% | 53,679 psi | 84% | 2917 fps | 100% |
| Lovex D073.6 | <<locked>> | 80% | 44,324 psi | 69% | 2799 fps | 100% |
| Lovex S060 | <<locked>> | 80% | 45,165 psi | 71% | 2753 fps | 99% |
| Lovex S062 | <<locked>> | 80% | 40,306 psi | 63% | 2703 fps | 99.1% |
| Lovex S065 | <<locked>> | 86% | 39,784 psi | 62% | 2687 fps | 95.2% |
| Lovex S070 | <<locked>> | 92% | 45,687 psi | 72% | 2831 fps | 95.7% |
| Norma 201 | <<locked>> | 80% | 44,324 psi | 69% | 2772 fps | 99.6% |
| Norma 202 | <<locked>> | 80% | 44,425 psi | 70% | 2776 fps | 100% |
| Norma 203B | <<locked>> | 80% | 40,234 psi | 63% | 2736 fps | 98.1% |
| Norma 204 | <<locked>> | 98% | 53,867 psi | 84% | 3009 fps | 95.3% |
| Norma URP | <<locked>> | 86% | 35,853 psi | 56% | 2677 fps | 95.3% |
| Ramshot Big Game | <<locked>> | 80% | 39,885 psi | 63% | 2749 fps | 97.9% |
| Ramshot Hunter | <<locked>> | 92% | 42,714 psi | 67% | 2835 fps | 95.6% |
| Ramshot TAC | <<locked>> | 80% | 47,239 psi | 74% | 2831 fps | 97.4% |
| Ramshot Wild Boar | <<locked>> | 80% | 46,615 psi | 73% | 2851 fps | 99.2% |
| Ramshot X-Terminator | <<locked>> | 80% | 50,981 psi | 80% | 2881 fps | 99.6% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 26,745 psi | 42% | 1683 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 80% | 52,750 psi | 83% | 2910 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 84% | 44,425 psi | 70% | 2785 fps | 95.8% |
| ReloadSwiss RS 52 | <<locked>> | 80% | 42,931 psi | 67% | 2854 fps | 98.2% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 34,969 psi | 55% | 2713 fps | 99.2% |
| ReloadSwiss RS 62 | <<locked>> | 88% | 37,855 psi | 59% | 2753 fps | 95.9% |
| ReloadSwiss RS 70 | <<locked>> | 90% | 40,524 psi | 64% | 2822 fps | 95.9% |
| Rottweil R 901 | <<locked>> | 80% | 48,298 psi | 76% | 2815 fps | 100% |
| Rottweil R 902 | <<locked>> | 80% | 42,090 psi | 66% | 2720 fps | 99.3% |
| Rottweil R 903 | <<locked>> | 80% | 35,433 psi | 56% | 2625 fps | 97.5% |
| Rottweil R 907 | <<locked>> | 90% | 46,659 psi | 73% | 2822 fps | 95% |
| Shooters World Long Rifle | <<locked>> | 86% | 39,784 psi | 62% | 2687 fps | 95.2% |
| Shooters World Match Rifle | <<locked>> | 80% | 44,324 psi | 69% | 2799 fps | 100% |
| Shooters World Precision | <<locked>> | 80% | 40,306 psi | 63% | 2703 fps | 99.1% |
| Shooters World SW4350 | <<locked>> | 92% | 45,687 psi | 72% | 2831 fps | 95.7% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 36,376 psi | 57% | 2677 fps | 97% |
| SNPE Vectan SP 7 | <<locked>> | 80% | 45,571 psi | 71% | 2805 fps | 97.6% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 43,569 psi | 68% | 2782 fps | 98.7% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 45,455 psi | 71% | 2723 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 37,855 psi | 59% | 2582 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 90% | 44,846 psi | 70% | 2746 fps | 95.2% |
| Somchem S321 | <<locked>> | 80% | 51,053 psi | 80% | 2910 fps | 100% |
| Somchem S335 | <<locked>> | 80% | 45,252 psi | 71% | 2726 fps | 100% |
| Somchem S341 | <<locked>> | 80% | 45,136 psi | 71% | 2802 fps | 98.9% |
| Somchem S355 | <<locked>> | 80% | 36,405 psi | 57% | 2638 fps | 97.6% |
| Somchem S365 | <<locked>> | 82% | 28,079 psi | 44% | 2503 fps | 95.7% |
| Unknown powder | <<locked>> | 86% | 39,001 psi | 61% | 2740 fps | 95.7% |
| Vihtavuori N130 | <<locked>> | 80% | 50,459 psi | 79% | 2776 fps | 100% |
| Vihtavuori N133 | <<locked>> | 80% | 42,859 psi | 67% | 2667 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 41,553 psi | 65% | 2703 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 41,684 psi | 65% | 2703 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 30,966 psi | 49% | 2480 fps | 97.2% |
| Vihtavuori N160 | <<locked>> | 84% | 36,550 psi | 57% | 2657 fps | 95.5% |
| Vihtavuori N530 | <<locked>> | 80% | 49,734 psi | 78% | 2884 fps | 100% |
| Vihtavuori N540 | <<locked>> | 80% | 41,321 psi | 65% | 2723 fps | 100% |
| Vihtavuori N550 | <<locked>> | 84% | 37,072 psi | 58% | 2700 fps | 95.6% |
| Vihtavuori N555 | <<locked>> | 92% | 33,257 psi | 52% | 2664 fps | 95.3% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 30,589 psi | 48% | 2484 fps | 95.5% |
| Winchester 748 | <<locked>> | 80% | 50,720 psi | 79% | 2933 fps | 100% |
| Winchester 760 | <<locked>> | 88% | 44,715 psi | 70% | 2871 fps | 95.2% |
| Winchester StaBALL HD | <<locked>> | 96% | 31,125 psi | 49% | 2667 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 99 powders for .300 WSM loaded with the .308 | 155gr | Norma Kalahari. ReloadSwiss RS 70 delivers the highest muzzle velocity at 3,143 fps; across all powders the maximum-charge window runs from 1,837 fps to 3,143 fps. Alliant Reloder-16 gives the best case fill at 100 %, and 99 of the 99 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (440 MPa), the top charges use 55–90 %, leaving at least 10 % headroom. The 155.0 gr projectile in 0.308" calls for a 1:12.5 twist; slower twists will usually not stabilise this weight. Alliant Reloder-16, Alliant Reloder-23, Alliant Reloder-26 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. Alliant Power Pro 2000-MR, Hodgdon Superformance, Alliant Reloder-17 rank at the top here: for .300 WSM with the .308 | 155gr | Norma Kalahari 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.