Load Specifications
Load data in caliber .300 WSM with .308 | 135gr | Sierra HPBT MatchKing bullet and 98 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, ReloadSwiss RS 60 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>> | 86% | 56,782 psi | 89% | 3120 fps | 100% |
| Accurate 2460 | <<locked>> | 82% | 55,288 psi | 87% | 3140 fps | 100% |
| Accurate 2495 | <<locked>> | 90% | 55,230 psi | 87% | 3133 fps | 100% |
| Accurate 2520 | <<locked>> | 86% | 55,666 psi | 87% | 3192 fps | 100% |
| Accurate 2520 | <<locked>> | 86% | 55,666 psi | 87% | 3192 fps | 100% |
| Accurate 4064 | <<locked>> | 92% | 55,216 psi | 87% | 3182 fps | 100% |
| Accurate 4350ᴾ | <<locked>> | 100% | 54,984 psi | 86% | 3255 fps | 98.9% |
| ADI AR 2206H | <<locked>> | 88% | 55,869 psi | 88% | 3215 fps | 99.6% |
| ADI AR 2208 | <<locked>> | 94% | 56,942 psi | 89% | 3212 fps | 99.4% |
| ADI Benchmark 8208 | <<locked>> | 86% | 54,897 psi | 86% | 3166 fps | 99.9% |
| Alliant AR-Comp | <<locked>> | 86% | 55,448 psi | 87% | 3150 fps | 100% |
| Alliant Power Pro 1200-R | <<locked>> | 82% | 56,724 psi | 89% | 3287 fps | 99.9% |
| Alliant Power Pro 2000-MR | <<locked>> | 90% | 55,521 psi | 87% | 3337 fps | 99.3% |
| Alliant Reloder- TS 15.5 | <<locked>> | 94% | 56,695 psi | 89% | 3235 fps | 99.9% |
| Alliant Reloder-10x | <<locked>> | 82% | 56,130 psi | 88% | 3123 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 92% | 57,450 psi | 90% | 3258 fps | 99.5% |
| Alliant Reloder-16ᴾ | <<locked>> | 100% | 52,881 psi | 83% | 3258 fps | 98.9% |
| Alliant Reloder-17 | <<locked>> | 96% | 54,056 psi | 85% | 3301 fps | 99.8% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 37,710 psi | 59% | 2943 fps | 96.7% |
| Baschieri & Pellagri 107 | <<locked>> | 88% | 55,811 psi | 87% | 3225 fps | 99.1% |
| Bofors RP3 | <<locked>> | 94% | 57,537 psi | 90% | 3251 fps | 100% |
| Hodgdon Benchmark | <<locked>> | 86% | 56,739 psi | 89% | 3153 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 86% | 54,172 psi | 85% | 3192 fps | 100% |
| Hodgdon CFE223 | <<locked>> | 84% | 56,144 psi | 88% | 3297 fps | 99.4% |
| Hodgdon H322 | <<locked>> | 84% | 54,650 psi | 86% | 3153 fps | 100% |
| Hodgdon H380 | <<locked>> | 92% | 54,998 psi | 86% | 3202 fps | 98.4% |
| Hodgdon H414 | <<locked>> | 96% | 56,130 psi | 88% | 3274 fps | 96.8% |
| Hodgdon H4895 | <<locked>> | 88% | 56,434 psi | 88% | 3228 fps | 99.8% |
| Hodgdon Hybrid 100Vᴾ | <<locked>> | 100% | 49,197 psi | 77% | 3123 fps | 99.3% |
| Hodgdon LEVERevolution | <<locked>> | 92% | 55,782 psi | 87% | 3261 fps | 99.9% |
| Hodgdon Superformance | <<locked>> | 98% | 55,477 psi | 87% | 3281 fps | 96.1% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 35,128 psi | 55% | 1988 fps | 100% |
| Hodgdon VARGET | <<locked>> | 92% | 56,492 psi | 89% | 3212 fps | 99.8% |
| IMR 3031 | <<locked>> | 90% | 54,563 psi | 86% | 3192 fps | 100% |
| IMR 4064 | <<locked>> | 94% | 55,608 psi | 87% | 3182 fps | 99.4% |
| IMR 4166 Enduron | <<locked>> | 94% | 55,027 psi | 86% | 3140 fps | 96.4% |
| IMR 4198 | <<locked>> | 82% | 56,014 psi | 88% | 3081 fps | 100% |
| IMR 4451 Enduron | <<locked>> | 96% | 56,101 psi | 88% | 3189 fps | 96.5% |
| IMR 4831ᴾ | <<locked>> | 100% | 46,253 psi | 72% | 3077 fps | 97.5% |
| IMR 4895 | <<locked>> | 90% | 55,303 psi | 87% | 3235 fps | 99.6% |
| IMR 8208 XBR | <<locked>> | 86% | 54,897 psi | 86% | 3166 fps | 99.9% |
| Lovex D073.5 | <<locked>> | 82% | 55,158 psi | 86% | 3150 fps | 100% |
| Lovex D073.6 | <<locked>> | 88% | 55,666 psi | 87% | 3192 fps | 100% |
| Lovex S060 | <<locked>> | 88% | 55,434 psi | 87% | 3140 fps | 99.6% |
| Lovex S062 | <<locked>> | 92% | 56,217 psi | 88% | 3192 fps | 100% |
| Lovex S065 | <<locked>> | 98% | 55,288 psi | 87% | 3179 fps | 97.8% |
| Lovex S070ᴾ | <<locked>> | 100% | 56,376 psi | 88% | 3215 fps | 97% |
| Norma 201 | <<locked>> | 88% | 54,462 psi | 85% | 3156 fps | 99.9% |
| Norma 202 | <<locked>> | 88% | 55,158 psi | 86% | 3163 fps | 100% |
| Norma 203B | <<locked>> | 92% | 56,608 psi | 89% | 3245 fps | 99.7% |
| Norma URPᴾ | <<locked>> | 100% | 54,143 psi | 85% | 3241 fps | 98.7% |
| Ramshot Big Game | <<locked>> | 92% | 57,392 psi | 90% | 3271 fps | 99.7% |
| Ramshot Hunterᴾ | <<locked>> | 100% | 52,997 psi | 83% | 3228 fps | 97.1% |
| Ramshot TAC | <<locked>> | 86% | 55,303 psi | 87% | 3176 fps | 98% |
| Ramshot Wild Boar | <<locked>> | 86% | 54,766 psi | 86% | 3199 fps | 99.5% |
| Ramshot X-Terminator | <<locked>> | 84% | 56,043 psi | 88% | 3166 fps | 99.5% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 35,621 psi | 56% | 2037 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 82% | 54,288 psi | 85% | 3146 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 92% | 55,376 psi | 87% | 3182 fps | 97.2% |
| ReloadSwiss RS 52 | <<locked>> | 88% | 54,157 psi | 85% | 3271 fps | 99.2% |
| ReloadSwiss RS 60 | <<locked>> | 96% | 57,638 psi | 90% | 3369 fps | 100% |
| ReloadSwiss RS 62ᴾ | <<locked>> | 100% | 54,781 psi | 86% | 3274 fps | 98.7% |
| ReloadSwiss RS 70ᴾ | <<locked>> | 100% | 54,766 psi | 86% | 3301 fps | 98.4% |
| Rottweil R 901 | <<locked>> | 86% | 55,593 psi | 87% | 3150 fps | 100% |
| Rottweil R 902 | <<locked>> | 90% | 55,013 psi | 86% | 3156 fps | 99.9% |
| Rottweil R 903 | <<locked>> | 96% | 57,363 psi | 90% | 3241 fps | 99.9% |
| Shooters World Long Rifle | <<locked>> | 98% | 55,288 psi | 87% | 3179 fps | 97.8% |
| Shooters World Match Rifle | <<locked>> | 88% | 55,666 psi | 87% | 3192 fps | 100% |
| Shooters World Precision | <<locked>> | 92% | 56,217 psi | 88% | 3192 fps | 100% |
| Shooters World SW4350ᴾ | <<locked>> | 100% | 56,376 psi | 88% | 3215 fps | 97% |
| Shooters World Tactical Rifle | <<locked>> | 82% | 57,580 psi | 90% | 3169 fps | 99.9% |
| SNPE Vectan SP 11 | <<locked>> | 94% | 55,651 psi | 87% | 3248 fps | 99.6% |
| SNPE Vectan SP 3 | <<locked>> | 82% | 57,014 psi | 89% | 3150 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 88% | 57,493 psi | 90% | 3212 fps | 98.7% |
| SNPE Vectan SP 9 | <<locked>> | 88% | 54,288 psi | 85% | 3179 fps | 99.5% |
| SNPE Vectan Tubal 3000 | <<locked>> | 88% | 56,115 psi | 88% | 3100 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 94% | 56,289 psi | 88% | 3094 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 98% | 56,057 psi | 88% | 3130 fps | 96.6% |
| Somchem S321 | <<locked>> | 84% | 56,333 psi | 88% | 3202 fps | 100% |
| Somchem S335 | <<locked>> | 88% | 55,434 psi | 87% | 3094 fps | 100% |
| Somchem S341 | <<locked>> | 88% | 56,956 psi | 89% | 3202 fps | 99.6% |
| Somchem S355 | <<locked>> | 96% | 57,682 psi | 90% | 3241 fps | 99.9% |
| Somchem S365ᴾ | <<locked>> | 100% | 48,530 psi | 76% | 3186 fps | 99.9% |
| Unknown powder | <<locked>> | 98% | 55,172 psi | 86% | 3248 fps | 98.3% |
| Vihtavuori N130 | <<locked>> | 84% | 54,665 psi | 86% | 3051 fps | 100% |
| Vihtavuori N133 | <<locked>> | 90% | 55,521 psi | 87% | 3077 fps | 100% |
| Vihtavuori N135 | <<locked>> | 90% | 54,679 psi | 86% | 3127 fps | 100% |
| Vihtavuori N140 | <<locked>> | 90% | 54,897 psi | 86% | 3130 fps | 100% |
| Vihtavuori N150ᴾ | <<locked>> | 100% | 55,463 psi | 87% | 3166 fps | 100% |
| Vihtavuori N160 | <<locked>> | 98% | 56,101 psi | 88% | 3222 fps | 98.9% |
| Vihtavuori N530 | <<locked>> | 84% | 54,534 psi | 85% | 3173 fps | 99.9% |
| Vihtavuori N540 | <<locked>> | 90% | 54,650 psi | 86% | 3156 fps | 100% |
| Vihtavuori N550 | <<locked>> | 98% | 56,086 psi | 88% | 3271 fps | 98.8% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 41,031 psi | 64% | 3031 fps | 96.8% |
| Winchester 6.5 StaBALLᴾ | <<locked>> | 100% | 57,696 psi | 90% | 3222 fps | 100% |
| Winchester 748 | <<locked>> | 84% | 55,999 psi | 88% | 3228 fps | 100% |
| Winchester 760 | <<locked>> | 96% | 56,130 psi | 88% | 3274 fps | 96.8% |
| Winchester StaBALL Match | <<locked>> | 82% | 55,535 psi | 87% | 3209 fps | 99.8% |
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% | 46,992 psi | 74% | 2963 fps | 100% |
| Accurate 2460 | <<locked>> | 80% | 51,619 psi | 81% | 3084 fps | 100% |
| Accurate 2495 | <<locked>> | 80% | 39,639 psi | 62% | 2864 fps | 100% |
| Accurate 2520 | <<locked>> | 80% | 45,063 psi | 71% | 3009 fps | 99.8% |
| Accurate 2520 | <<locked>> | 80% | 45,063 psi | 71% | 3009 fps | 99.8% |
| Accurate 4064 | <<locked>> | 80% | 37,449 psi | 59% | 2848 fps | 99.5% |
| Accurate 4350 | <<locked>> | 90% | 38,696 psi | 61% | 2930 fps | 95.2% |
| ADI AR 2206H | <<locked>> | 80% | 43,366 psi | 68% | 2976 fps | 97.8% |
| ADI AR 2208 | <<locked>> | 80% | 36,811 psi | 58% | 2802 fps | 95.1% |
| ADI Benchmark 8208 | <<locked>> | 80% | 45,440 psi | 71% | 2992 fps | 99.1% |
| Alliant AR-Comp | <<locked>> | 80% | 45,324 psi | 71% | 2989 fps | 100% |
| Alliant Power Pro 1200-R | <<locked>> | 80% | 53,084 psi | 83% | 3225 fps | 99.6% |
| Alliant Power Pro 2000-MR | 60 gr | 80% | 39,276 psi | 62% | 2986 fps | 95.6% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 36,260 psi | 57% | 2825 fps | 96.8% |
| Alliant Reloder-10x | <<locked>> | 80% | 52,823 psi | 83% | 3074 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 39,131 psi | 61% | 2897 fps | 96.1% |
| Alliant Reloder-16 | <<locked>> | 90% | 38,769 psi | 61% | 2946 fps | 95.2% |
| Alliant Reloder-17 | 60.6 gr | 82% | 33,620 psi | 53% | 2835 fps | 95% |
| Alliant Reloder-23 | <<locked>> | 98% | 35,418 psi | 56% | 2881 fps | 95.8% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 42,438 psi | 67% | 2969 fps | 96.5% |
| Bofors RP3 | <<locked>> | 80% | 35,969 psi | 56% | 2828 fps | 96.8% |
| Hodgdon Benchmark | <<locked>> | 80% | 47,152 psi | 74% | 2986 fps | 99.6% |
| Hodgdon BL-C2 | <<locked>> | 80% | 44,106 psi | 69% | 3005 fps | 99.3% |
| Hodgdon CFE223 | <<locked>> | 80% | 48,573 psi | 76% | 3163 fps | 98.4% |
| Hodgdon H322 | <<locked>> | 80% | 48,066 psi | 75% | 3045 fps | 100% |
| Hodgdon H380 | <<locked>> | 84% | 42,206 psi | 66% | 2956 fps | 95.7% |
| Hodgdon H414 | <<locked>> | 92% | 48,776 psi | 76% | 3140 fps | 95.1% |
| Hodgdon H4895 | <<locked>> | 80% | 43,787 psi | 69% | 2992 fps | 98.4% |
| Hodgdon Hybrid 100V | <<locked>> | 88% | 33,373 psi | 52% | 2769 fps | 95.1% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 37,333 psi | 59% | 2890 fps | 97.2% |
| Hodgdon Superformance | <<locked>> | 96% | 51,764 psi | 81% | 3212 fps | 95.2% |
| Hodgdon TrailBoss | <<locked>> | 80% | 26,179 psi | 41% | 1781 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 38,798 psi | 61% | 2864 fps | 97.1% |
| IMR 3031 | <<locked>> | 80% | 39,508 psi | 62% | 2920 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 35,984 psi | 56% | 2776 fps | 95.1% |
| IMR 4166 Enduron | <<locked>> | 92% | 51,924 psi | 81% | 3087 fps | 95.7% |
| IMR 4198 | <<locked>> | 80% | 52,721 psi | 83% | 3031 fps | 100% |
| IMR 4451 Enduron | <<locked>> | 92% | 49,559 psi | 78% | 3068 fps | 95% |
| IMR 4831 | <<locked>> | 94% | 38,087 psi | 60% | 2900 fps | 95.1% |
| IMR 4895 | <<locked>> | 80% | 40,089 psi | 63% | 2933 fps | 97.1% |
| IMR 8208 XBR | <<locked>> | 80% | 45,440 psi | 71% | 2992 fps | 99.1% |
| Lovex D073.5 | <<locked>> | 80% | 51,532 psi | 81% | 3091 fps | 100% |
| Lovex D073.6 | <<locked>> | 80% | 42,395 psi | 66% | 2956 fps | 99.6% |
| Lovex S060 | <<locked>> | 80% | 43,381 psi | 68% | 2910 fps | 97.9% |
| Lovex S062 | <<locked>> | 80% | 38,464 psi | 60% | 2848 fps | 97.9% |
| Lovex S065 | <<locked>> | 90% | 43,192 psi | 68% | 2946 fps | 95% |
| Lovex S070 | <<locked>> | 96% | 49,647 psi | 78% | 3094 fps | 95.5% |
| Norma 201 | <<locked>> | 80% | 42,366 psi | 66% | 2927 fps | 98.7% |
| Norma 202 | <<locked>> | 80% | 42,598 psi | 67% | 2940 fps | 99.9% |
| Norma 203B | <<locked>> | 80% | 38,522 psi | 60% | 2887 fps | 96.6% |
| Norma URP | <<locked>> | 90% | 38,856 psi | 61% | 2933 fps | 95.1% |
| Ramshot Big Game | <<locked>> | 80% | 37,898 psi | 59% | 2887 fps | 96.1% |
| Ramshot Hunter | <<locked>> | 96% | 46,398 psi | 73% | 3097 fps | 95.4% |
| Ramshot TAC | <<locked>> | 80% | 45,426 psi | 71% | 2989 fps | 95.8% |
| Ramshot Wild Boar | <<locked>> | 80% | 44,788 psi | 70% | 3012 fps | 98.1% |
| Ramshot X-Terminator | <<locked>> | 80% | 49,168 psi | 77% | 3045 fps | 98.8% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 26,527 psi | 42% | 1824 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 80% | 50,952 psi | 80% | 3091 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 88% | 48,646 psi | 76% | 3058 fps | 95.7% |
| ReloadSwiss RS 52 | <<locked>> | 80% | 40,857 psi | 64% | 3005 fps | 96.6% |
| ReloadSwiss RS 60 | 59.1 gr | 80% | 33,431 psi | 52% | 2844 fps | 97.6% |
| ReloadSwiss RS 62 | <<locked>> | 92% | 41,321 psi | 65% | 3015 fps | 95.7% |
| ReloadSwiss RS 70 | <<locked>> | 94% | 44,483 psi | 70% | 3091 fps | 95.8% |
| Rottweil R 901 | <<locked>> | 80% | 46,209 psi | 72% | 2986 fps | 100% |
| Rottweil R 902 | <<locked>> | 80% | 40,277 psi | 63% | 2871 fps | 98.2% |
| Rottweil R 903 | <<locked>> | 80% | 33,678 psi | 53% | 2759 fps | 95.7% |
| Shooters World Long Rifle | <<locked>> | 90% | 43,192 psi | 68% | 2946 fps | 95% |
| Shooters World Match Rifle | <<locked>> | 80% | 42,395 psi | 66% | 2956 fps | 99.6% |
| Shooters World Precision | <<locked>> | 80% | 38,464 psi | 60% | 2848 fps | 97.9% |
| Shooters World SW4350 | <<locked>> | 96% | 49,647 psi | 78% | 3094 fps | 95.5% |
| Shooters World Tactical Rifle | <<locked>> | 80% | 53,751 psi | 84% | 3110 fps | 99.8% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 34,780 psi | 55% | 2815 fps | 95% |
| SNPE Vectan SP 3 | <<locked>> | 80% | 53,606 psi | 84% | 3097 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 80% | 43,700 psi | 68% | 2959 fps | 96% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 41,887 psi | 66% | 2940 fps | 97.5% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 43,816 psi | 69% | 2890 fps | 99.9% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 36,332 psi | 57% | 2736 fps | 99.7% |
| SNPE Vectan Tubal 7000 | <<locked>> | 94% | 49,182 psi | 77% | 3012 fps | 95.1% |
| Somchem S321 | <<locked>> | 80% | 49,037 psi | 77% | 3077 fps | 99.7% |
| Somchem S335 | <<locked>> | 80% | 43,381 psi | 68% | 2890 fps | 100% |
| Somchem S341 | <<locked>> | 80% | 43,250 psi | 68% | 2953 fps | 97.7% |
| Somchem S355 | <<locked>> | 80% | 34,621 psi | 54% | 2772 fps | 95.8% |
| Somchem S365 | <<locked>> | 86% | 30,560 psi | 48% | 2749 fps | 95.4% |
| Unknown powder | <<locked>> | 90% | 42,395 psi | 66% | 3002 fps | 95.5% |
| Vihtavuori N130 | <<locked>> | 80% | 48,573 psi | 76% | 2956 fps | 100% |
| Vihtavuori N133 | <<locked>> | 80% | 41,249 psi | 65% | 2835 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 39,653 psi | 62% | 2864 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 39,929 psi | 63% | 2861 fps | 99.8% |
| Vihtavuori N150 | <<locked>> | 80% | 29,559 psi | 46% | 2612 fps | 95.3% |
| Vihtavuori N160 | <<locked>> | 88% | 39,914 psi | 63% | 2913 fps | 95.3% |
| Vihtavuori N530 | <<locked>> | 80% | 47,834 psi | 75% | 3054 fps | 99.5% |
| Vihtavuori N540 | <<locked>> | 80% | 39,595 psi | 62% | 2877 fps | 99.6% |
| Vihtavuori N550 | <<locked>> | 88% | 40,248 psi | 63% | 2959 fps | 95.3% |
| Vihtavuori N555 | <<locked>> | 98% | 38,348 psi | 60% | 2969 fps | 95.9% |
| Winchester 6.5 StaBALL | <<locked>> | 84% | 33,605 psi | 53% | 2730 fps | 95.4% |
| Winchester 748 | <<locked>> | 80% | 48,530 psi | 76% | 3100 fps | 99.9% |
| Winchester 760 | <<locked>> | 92% | 48,776 psi | 76% | 3140 fps | 95.1% |
| Winchester StaBALL Match | <<locked>> | 80% | 51,634 psi | 81% | 3146 fps | 99.5% |
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 114 powders for .300 WSM loaded with the .308 | 135gr | Sierra HPBT MatchKing. ReloadSwiss RS 60 delivers the highest muzzle velocity at 3,369 fps; across all powders the maximum-charge window runs from 1,988 fps to 3,369 fps. Accurate 3100 gives the best case fill at 100 %, and 114 of the 114 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (440 MPa), the top charges use 53–90 %, leaving at least 10 % headroom. The 135.0 gr projectile in 0.308" calls for a 1:15.0 twist; slower twists will usually not stabilise this weight. Accurate 3100, Accurate 4350, ADI AR 2209 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, ReloadSwiss RS 60, Alliant Reloder-17 rank at the top here: for .300 WSM with the .308 | 135gr | Sierra HPBT MatchKing they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, Accurate 3100, ADI AR 2209, Alliant Reloder-19 burn incompletely and react more sensitively to barrel length and temperature. Always begin at the start load and work up in small increments while checking case and primer for pressure signs.