Load Specifications
Load data in caliber .300 Weath. Mag. with .308 | 165gr | Sierra SBT GameKing bullet and 84 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Norma MRP, Vihtavuori N560 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.
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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 2700 | <<locked>> | 82% | 56,347 psi | 88% | 2963 fps | 99% |
| Accurate 3100 | <<locked>> | 98% | 55,579 psi | 87% | 3012 fps | 99.8% |
| Accurate 4064 | <<locked>> | 82% | 55,985 psi | 88% | 2943 fps | 100% |
| Accurate 4350 | <<locked>> | 90% | 57,232 psi | 90% | 3058 fps | 100% |
| ADI AR 2208 | <<locked>> | 84% | 55,608 psi | 87% | 2976 fps | 100% |
| ADI AR 2209 | <<locked>> | 94% | 54,375 psi | 85% | 3045 fps | 98.1% |
| ADI AR 2213 | <<locked>> | 98% | 55,883 psi | 88% | 3104 fps | 97.3% |
| Alliant Power Pro Varmint | <<locked>> | 94% | 54,723 psi | 86% | 3045 fps | 98.2% |
| Alliant Reloder- TS 15.5 | <<locked>> | 84% | 56,681 psi | 89% | 2999 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 82% | 56,840 psi | 89% | 3022 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 90% | 54,346 psi | 85% | 3061 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 86% | 55,550 psi | 87% | 3081 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 96% | 57,479 psi | 90% | 3094 fps | 98.7% |
| Alliant Reloder-22 | <<locked>> | 98% | 55,347 psi | 87% | 3100 fps | 98.5% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 55,956 psi | 88% | 3081 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 48,501 psi | 76% | 3012 fps | 99.7% |
| Alliant Reloder-26 | <<locked>> | 96% | 56,565 psi | 89% | 3173 fps | 100% |
| Bofors RP15ᴾ | <<locked>> | 100% | 54,070 psi | 85% | 3077 fps | 98.2% |
| Bofors RP3 | <<locked>> | 82% | 54,012 psi | 85% | 2963 fps | 100% |
| Bofors RP5 | <<locked>> | 98% | 55,347 psi | 87% | 3100 fps | 98.5% |
| Bofors RP7 | <<locked>> | 88% | 56,768 psi | 89% | 3005 fps | 99.1% |
| Hodgdon H1000ᴾ | <<locked>> | 100% | 48,066 psi | 75% | 2949 fps | 96.3% |
| Hodgdon H380 | <<locked>> | 82% | 54,331 psi | 85% | 2979 fps | 100% |
| Hodgdon H414 | <<locked>> | 88% | 55,550 psi | 87% | 3054 fps | 99.4% |
| Hodgdon H4350 | <<locked>> | 86% | 54,984 psi | 86% | 3012 fps | 98.5% |
| Hodgdon H4831 | <<locked>> | 96% | 55,898 psi | 88% | 3041 fps | 96.6% |
| Hodgdon H4831 SC | <<locked>> | 96% | 54,781 psi | 86% | 3025 fps | 96.4% |
| Hodgdon Hybrid 100V | <<locked>> | 92% | 54,694 psi | 86% | 2982 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 47,485 psi | 74% | 3051 fps | 97.7% |
| Hodgdon Superformance | <<locked>> | 88% | 55,898 psi | 88% | 3091 fps | 99.3% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,695 psi | 57% | 1900 fps | 100% |
| IMR 4064 | <<locked>> | 82% | 55,085 psi | 86% | 2959 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 82% | 57,508 psi | 90% | 2995 fps | 99.5% |
| IMR 4350 | <<locked>> | 90% | 54,534 psi | 85% | 2986 fps | 98.9% |
| IMR 4451 Enduron | <<locked>> | 86% | 54,984 psi | 86% | 2979 fps | 99.2% |
| IMR 4831 | <<locked>> | 92% | 57,624 psi | 90% | 3051 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 96% | 57,261 psi | 90% | 3031 fps | 97.1% |
| IMR 7828 SSCᴾ | <<locked>> | 100% | 57,130 psi | 90% | 3136 fps | 97.7% |
| Lovex S062 | <<locked>> | 82% | 55,521 psi | 87% | 2953 fps | 100% |
| Lovex S065 | <<locked>> | 88% | 55,288 psi | 87% | 2976 fps | 99.8% |
| Lovex S070 | <<locked>> | 90% | 56,666 psi | 89% | 3018 fps | 99.5% |
| Lovex S071ᴾ | <<locked>> | 100% | 49,342 psi | 77% | 2910 fps | 99.2% |
| Norma 203B | <<locked>> | 82% | 56,130 psi | 88% | 3009 fps | 100% |
| Norma 204 | <<locked>> | 90% | 55,477 psi | 87% | 3041 fps | 98.2% |
| Norma MRP | <<locked>> | 96% | 55,013 psi | 86% | 3127 fps | 99.4% |
| Norma URP | <<locked>> | 90% | 55,724 psi | 87% | 3041 fps | 100% |
| Ramshot Big Game | <<locked>> | 82% | 57,058 psi | 89% | 3035 fps | 100% |
| Ramshot Grand | <<locked>> | 98% | 53,838 psi | 84% | 3091 fps | 97.4% |
| Ramshot Hunter | <<locked>> | 90% | 54,665 psi | 86% | 3041 fps | 99.7% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 52,069 psi | 82% | 3028 fps | 98.6% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,362 psi | 59% | 1942 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 82% | 54,041 psi | 85% | 2963 fps | 99.5% |
| ReloadSwiss RS 60 | <<locked>> | 84% | 55,042 psi | 86% | 3074 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 90% | 57,276 psi | 90% | 3084 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 90% | 55,579 psi | 87% | 3110 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 47,805 psi | 75% | 3051 fps | 98.8% |
| Rottweil R 902 | <<locked>> | 82% | 57,392 psi | 90% | 2963 fps | 100% |
| Rottweil R 903 | <<locked>> | 84% | 54,302 psi | 85% | 2959 fps | 100% |
| Rottweil R 904 | <<locked>> | 94% | 56,057 psi | 88% | 3022 fps | 97.4% |
| Rottweil R 905 | <<locked>> | 96% | 56,898 psi | 89% | 3081 fps | 98.7% |
| Rottweil R 907 | <<locked>> | 88% | 56,768 psi | 89% | 3005 fps | 99.1% |
| Shooters World Long Rifle | <<locked>> | 88% | 55,288 psi | 87% | 2976 fps | 99.8% |
| Shooters World Precision | <<locked>> | 82% | 55,521 psi | 87% | 2953 fps | 100% |
| Shooters World SW4350 | <<locked>> | 90% | 56,666 psi | 89% | 3018 fps | 99.5% |
| SNPE Vectan SP 11 | <<locked>> | 84% | 55,709 psi | 87% | 3018 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 84% | 54,882 psi | 86% | 2844 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 88% | 54,665 psi | 86% | 2923 fps | 99.2% |
| SNPE Vectan Tubal 8000 | <<locked>> | 96% | 56,434 psi | 88% | 3074 fps | 98.6% |
| Somchem S355 | <<locked>> | 86% | 57,725 psi | 90% | 3012 fps | 100% |
| Somchem S361 | <<locked>> | 92% | 54,157 psi | 85% | 2949 fps | 96.3% |
| Somchem S365 | <<locked>> | 92% | 55,666 psi | 87% | 3045 fps | 100% |
| Somchem S385 | <<locked>> | 96% | 57,537 psi | 90% | 3054 fps | 99.2% |
| Vihtavuori N150 | <<locked>> | 86% | 55,303 psi | 87% | 2930 fps | 100% |
| Vihtavuori N160 | <<locked>> | 90% | 57,725 psi | 90% | 3035 fps | 100% |
| Vihtavuori N165ᴾ | <<locked>> | 100% | 57,058 psi | 89% | 3031 fps | 99% |
| Vihtavuori N540 | <<locked>> | 82% | 56,159 psi | 88% | 2930 fps | 100% |
| Vihtavuori N550 | <<locked>> | 90% | 57,043 psi | 89% | 3041 fps | 100% |
| Vihtavuori N555 | <<locked>> | 96% | 54,969 psi | 86% | 3058 fps | 100% |
| Vihtavuori N560 | <<locked>> | 96% | 55,071 psi | 86% | 3114 fps | 96.8% |
| Vihtavuori N565ᴾ | <<locked>> | 100% | 50,720 psi | 79% | 3018 fps | 96.1% |
| Winchester 6.5 StaBALL | <<locked>> | 90% | 57,508 psi | 90% | 2999 fps | 100% |
| Winchester 760 | <<locked>> | 88% | 55,767 psi | 87% | 3058 fps | 99.4% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 52,417 psi | 82% | 3156 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 98% | 57,653 psi | 90% | 3051 fps | 98.6% |
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 2700 | <<locked>> | 80% | 52,620 psi | 82% | 2900 fps | 98.4% |
| Accurate 3100 | <<locked>> | 84% | 34,563 psi | 54% | 2602 fps | 95.5% |
| Accurate 4064 | <<locked>> | 80% | 52,634 psi | 82% | 2894 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 40,611 psi | 64% | 2759 fps | 98.8% |
| ADI AR 2208 | <<locked>> | 80% | 49,197 psi | 77% | 2867 fps | 100% |
| ADI AR 2209 | <<locked>> | 88% | 44,672 psi | 70% | 2861 fps | 95.9% |
| ADI AR 2213 | <<locked>> | 94% | 48,733 psi | 76% | 2972 fps | 95.6% |
| Alliant Power Pro Varmint | <<locked>> | 86% | 41,989 psi | 66% | 2802 fps | 95.1% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 50,096 psi | 79% | 2894 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 53,229 psi | 83% | 2966 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 80% | 39,218 psi | 61% | 2769 fps | 98.9% |
| Alliant Reloder-17 | <<locked>> | 80% | 44,918 psi | 70% | 2904 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 86% | 41,597 psi | 65% | 2795 fps | 95% |
| Alliant Reloder-22 | <<locked>> | 90% | 42,264 psi | 66% | 2848 fps | 95.4% |
| Alliant Reloder-23 | <<locked>> | 80% | 28,993 psi | 45% | 2513 fps | 96.9% |
| Alliant Reloder-25 | <<locked>> | 88% | 32,895 psi | 52% | 2638 fps | 95.3% |
| Alliant Reloder-26 | 71.4 gr | 80% | 31,154 psi | 49% | 2628 fps | 95.3% |
| Bofors RP15 | <<locked>> | 92% | 41,684 psi | 65% | 2835 fps | 95% |
| Bofors RP3 | <<locked>> | 80% | 50,705 psi | 79% | 2910 fps | 100% |
| Bofors RP5 | <<locked>> | 90% | 42,264 psi | 66% | 2848 fps | 95.4% |
| Bofors RP7 | <<locked>> | 80% | 44,179 psi | 69% | 2776 fps | 96.9% |
| Hodgdon H1000 | <<locked>> | 98% | 44,831 psi | 70% | 2881 fps | 95.3% |
| Hodgdon H380 | <<locked>> | 80% | 50,850 psi | 80% | 2920 fps | 99.8% |
| Hodgdon H414 | <<locked>> | 80% | 42,540 psi | 67% | 2808 fps | 97.1% |
| Hodgdon H4350 | <<locked>> | 80% | 45,339 psi | 71% | 2835 fps | 96.5% |
| Hodgdon H4831 | <<locked>> | 94% | 52,199 psi | 82% | 2979 fps | 95.8% |
| Hodgdon H4831 SC | <<locked>> | 94% | 51,155 psi | 80% | 2963 fps | 95.6% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 36,898 psi | 58% | 2657 fps | 99.3% |
| Hodgdon Retumbo | <<locked>> | 96% | 41,713 psi | 65% | 2917 fps | 95.7% |
| Hodgdon Superformance | <<locked>> | 80% | 41,597 psi | 65% | 2825 fps | 96.5% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,427 psi | 43% | 1696 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 51,721 psi | 81% | 2904 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 80% | 53,954 psi | 85% | 2940 fps | 99.1% |
| IMR 4350 | <<locked>> | 80% | 39,827 psi | 62% | 2700 fps | 95.7% |
| IMR 4451 Enduron | <<locked>> | 80% | 45,498 psi | 71% | 2802 fps | 97.7% |
| IMR 4831 | <<locked>> | 80% | 38,914 psi | 61% | 2710 fps | 98.5% |
| IMR 4955 Enduron | <<locked>> | 92% | 50,517 psi | 79% | 2913 fps | 95.6% |
| IMR 7828 SSC | <<locked>> | 94% | 46,644 psi | 73% | 2943 fps | 95.1% |
| Lovex S062 | <<locked>> | 80% | 52,025 psi | 82% | 2897 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 43,178 psi | 68% | 2756 fps | 98.4% |
| Lovex S070 | <<locked>> | 80% | 41,394 psi | 65% | 2733 fps | 96.9% |
| Lovex S071 | <<locked>> | 88% | 33,562 psi | 53% | 2575 fps | 95.1% |
| Norma 203B | <<locked>> | 80% | 52,591 psi | 82% | 2949 fps | 100% |
| Norma 204 | <<locked>> | 82% | 42,177 psi | 66% | 2789 fps | 95% |
| Norma MRP | 74.5 gr | 86% | 38,580 psi | 60% | 2795 fps | 95.7% |
| Norma URP | <<locked>> | 80% | 40,205 psi | 63% | 2753 fps | 98.6% |
| Ramshot Big Game | <<locked>> | 80% | 53,447 psi | 84% | 2979 fps | 100% |
| Ramshot Grand | <<locked>> | 94% | 46,673 psi | 73% | 2956 fps | 95.5% |
| Ramshot Hunter | <<locked>> | 80% | 39,059 psi | 61% | 2740 fps | 96.9% |
| Ramshot Magnum | <<locked>> | 94% | 41,597 psi | 65% | 2822 fps | 96% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,934 psi | 44% | 1736 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 50,647 psi | 79% | 2904 fps | 99.1% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 47,659 psi | 75% | 2956 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 40,466 psi | 63% | 2779 fps | 98.6% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 39,073 psi | 61% | 2789 fps | 98.1% |
| ReloadSwiss RS 76 | <<locked>> | 94% | 38,508 psi | 60% | 2828 fps | 95.7% |
| Rottweil R 902 | <<locked>> | 80% | 53,925 psi | 85% | 2913 fps | 100% |
| Rottweil R 903 | <<locked>> | 80% | 47,630 psi | 75% | 2851 fps | 100% |
| Rottweil R 904 | <<locked>> | 88% | 46,311 psi | 73% | 2844 fps | 95.1% |
| Rottweil R 905 | <<locked>> | 86% | 40,828 psi | 64% | 2779 fps | 95% |
| Rottweil R 907 | <<locked>> | 80% | 44,179 psi | 69% | 2776 fps | 96.9% |
| Shooters World Long Rifle | <<locked>> | 80% | 43,178 psi | 68% | 2756 fps | 98.4% |
| Shooters World Precision | <<locked>> | 80% | 52,025 psi | 82% | 2897 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 41,394 psi | 65% | 2733 fps | 96.9% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 48,878 psi | 77% | 2907 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 48,385 psi | 76% | 2746 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 42,264 psi | 66% | 2697 fps | 97.1% |
| SNPE Vectan Tubal 8000 | <<locked>> | 88% | 43,178 psi | 68% | 2831 fps | 95.7% |
| Somchem S355 | <<locked>> | 80% | 47,776 psi | 75% | 2848 fps | 100% |
| Somchem S361 | <<locked>> | 90% | 50,589 psi | 79% | 2890 fps | 95.4% |
| Somchem S365 | <<locked>> | 80% | 36,869 psi | 58% | 2710 fps | 99.9% |
| Somchem S385 | <<locked>> | 84% | 38,769 psi | 61% | 2700 fps | 95.2% |
| Vihtavuori N150 | <<locked>> | 80% | 45,643 psi | 72% | 2772 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 41,553 psi | 65% | 2753 fps | 98.9% |
| Vihtavuori N165 | <<locked>> | 90% | 40,799 psi | 64% | 2736 fps | 95.5% |
| Vihtavuori N540 | <<locked>> | 80% | 52,721 psi | 83% | 2877 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 41,118 psi | 64% | 2756 fps | 98.7% |
| Vihtavuori N555 | <<locked>> | 80% | 32,227 psi | 51% | 2592 fps | 97% |
| Vihtavuori N560 | 79.7 gr | 92% | 47,877 psi | 75% | 2979 fps | 95% |
| Vihtavuori N565 | <<locked>> | 98% | 47,355 psi | 74% | 2953 fps | 95.2% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 40,698 psi | 64% | 2720 fps | 99.9% |
| Winchester 760 | <<locked>> | 80% | 42,540 psi | 67% | 2808 fps | 97.1% |
| Winchester StaBALL HD | <<locked>> | 80% | 25,657 psi | 40% | 2480 fps | 95.7% |
| Winchester Supreme 780 | <<locked>> | 90% | 43,801 psi | 69% | 2805 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 84 powders for .300 Weath. Mag. loaded with the .308 | 165gr | Sierra SBT GameKing. Alliant Reloder-26 delivers the highest muzzle velocity at 3,173 fps; across all powders the maximum-charge window runs from 1,900 fps to 3,173 fps. Alliant Reloder-23 gives the best case fill at 100 %, and 84 of the 84 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (440 MPa), the top charges use 57–90 %, leaving at least 10 % headroom. The 165.0 gr projectile in 0.308" calls for a 1:13.5 twist; slower twists will usually not stabilise this weight. Alliant Reloder-23, Alliant Reloder-25, Bofors RP15 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. Norma MRP, Vihtavuori N560, Alliant Reloder-26 rank at the top here: for .300 Weath. Mag. with the .308 | 165gr | Sierra SBT GameKing 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.