Load Specifications
Load data in caliber .300 Weath. Mag. with .308 | 171gr | Viper Bullets Bush Gold bullet and 83 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Alliant Reloder-26, Accurate High Country and Norma MRP.
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 2700 | <<locked>> | 82% | 57,725 psi | 90% | 2940 fps | 99.3% |
| Accurate 3100 | <<locked>> | 98% | 57,653 psi | 90% | 2995 fps | 99.9% |
| Accurate 4350 | <<locked>> | 88% | 55,637 psi | 87% | 2986 fps | 100% |
| Accurate High Country | <<locked>> | 94% | 55,259 psi | 87% | 3087 fps | 97.9% |
| Accurate MAGPRO | <<locked>> | 96% | 56,188 psi | 88% | 3087 fps | 96.8% |
| ADI AR 2208 | <<locked>> | 84% | 57,232 psi | 90% | 2953 fps | 100% |
| ADI AR 2209 | <<locked>> | 94% | 56,449 psi | 88% | 3038 fps | 98.8% |
| ADI AR 2213 | <<locked>> | 96% | 53,983 psi | 85% | 3028 fps | 97.4% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 39,972 psi | 63% | 2795 fps | 97% |
| Alliant Power Pro Varmint | <<locked>> | 94% | 56,565 psi | 89% | 3031 fps | 98.8% |
| Alliant Power Pro Varmint | <<locked>> | 94% | 56,565 psi | 89% | 3031 fps | 98.8% |
| Alliant Reloder- TS 15.5 | <<locked>> | 82% | 54,781 psi | 86% | 2920 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 90% | 56,347 psi | 88% | 3045 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 86% | 57,653 psi | 90% | 3061 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 94% | 55,825 psi | 87% | 3022 fps | 98.7% |
| Alliant Reloder-22 | <<locked>> | 98% | 57,377 psi | 90% | 3087 fps | 99% |
| Alliant Reloder-23 | <<locked>> | 98% | 54,520 psi | 85% | 3009 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 50,314 psi | 79% | 2999 fps | 99.9% |
| Alliant Reloder-26 | <<locked>> | 94% | 54,969 psi | 86% | 3097 fps | 100% |
| Bofors RP15ᴾ | <<locked>> | 100% | 56,289 psi | 88% | 3068 fps | 98.8% |
| Bofors RP3 | <<locked>> | 82% | 55,796 psi | 87% | 2940 fps | 100% |
| Bofors RP30ᴾ | <<locked>> | 100% | 46,369 psi | 73% | 2920 fps | 96.3% |
| Bofors RP5 | <<locked>> | 98% | 57,377 psi | 90% | 3087 fps | 99% |
| Bofors RP7 | <<locked>> | 86% | 54,998 psi | 86% | 2933 fps | 99.2% |
| Hodgdon H1000ᴾ | <<locked>> | 100% | 49,719 psi | 78% | 2943 fps | 97.3% |
| Hodgdon H380 | <<locked>> | 82% | 55,854 psi | 88% | 2956 fps | 100% |
| Hodgdon H414 | <<locked>> | 88% | 57,435 psi | 90% | 3038 fps | 99.7% |
| Hodgdon H4350 | <<locked>> | 86% | 56,695 psi | 89% | 2995 fps | 99% |
| Hodgdon H4831 | <<locked>> | 94% | 53,998 psi | 85% | 2969 fps | 96.7% |
| Hodgdon H4831 SC | <<locked>> | 96% | 56,637 psi | 89% | 3012 fps | 97.2% |
| Hodgdon Hybrid 100V | <<locked>> | 92% | 56,652 psi | 89% | 2963 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 49,284 psi | 77% | 3048 fps | 98.6% |
| Hodgdon Superformance | <<locked>> | 86% | 53,925 psi | 85% | 3012 fps | 99.3% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,738 psi | 58% | 1867 fps | 100% |
| IMR 4064 | <<locked>> | 82% | 56,724 psi | 89% | 2933 fps | 100% |
| IMR 4350 | <<locked>> | 90% | 56,217 psi | 88% | 2969 fps | 99.3% |
| IMR 4451 Enduron | <<locked>> | 86% | 56,333 psi | 88% | 2956 fps | 99.5% |
| IMR 4831 | <<locked>> | 90% | 55,825 psi | 87% | 2976 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 94% | 55,535 psi | 87% | 2959 fps | 97.2% |
| IMR 7828 SSC | <<locked>> | 98% | 55,463 psi | 87% | 3068 fps | 97.8% |
| Lovex S062 | <<locked>> | 82% | 56,971 psi | 89% | 2927 fps | 100% |
| Lovex S065 | <<locked>> | 88% | 56,942 psi | 89% | 2956 fps | 100% |
| Lovex S070 | <<locked>> | 88% | 54,984 psi | 86% | 2946 fps | 99.6% |
| Lovex S071ᴾ | <<locked>> | 100% | 51,256 psi | 80% | 2900 fps | 99.6% |
| Norma 204 | <<locked>> | 90% | 57,305 psi | 90% | 3025 fps | 98.7% |
| Norma MRP | <<locked>> | 96% | 57,174 psi | 90% | 3110 fps | 99.7% |
| Norma URP | <<locked>> | 90% | 57,609 psi | 90% | 3022 fps | 100% |
| Ramshot Grand | <<locked>> | 98% | 56,159 psi | 88% | 3087 fps | 98.2% |
| Ramshot Hunter | <<locked>> | 90% | 56,536 psi | 89% | 3025 fps | 99.9% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 54,186 psi | 85% | 3018 fps | 99.2% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,608 psi | 59% | 1913 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 82% | 55,637 psi | 87% | 2943 fps | 99.8% |
| ReloadSwiss RS 60 | <<locked>> | 84% | 57,217 psi | 90% | 3051 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 88% | 55,506 psi | 87% | 3009 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 90% | 57,624 psi | 90% | 3094 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 49,690 psi | 78% | 3048 fps | 99.4% |
| Rottweil R 903 | <<locked>> | 84% | 56,101 psi | 88% | 2940 fps | 100% |
| Rottweil R 904 | <<locked>> | 92% | 54,157 psi | 85% | 2946 fps | 97.5% |
| Rottweil R 905 | <<locked>> | 94% | 55,245 psi | 87% | 3009 fps | 98.7% |
| Rottweil R 907 | <<locked>> | 86% | 54,998 psi | 86% | 2933 fps | 99.2% |
| Shooters World Long Rifle | <<locked>> | 88% | 56,942 psi | 89% | 2956 fps | 100% |
| Shooters World Precision | <<locked>> | 82% | 56,971 psi | 89% | 2927 fps | 100% |
| Shooters World SW4350 | <<locked>> | 88% | 54,984 psi | 86% | 2946 fps | 99.6% |
| SNPE Vectan SP 11 | <<locked>> | 84% | 57,537 psi | 90% | 2995 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 84% | 56,231 psi | 88% | 2815 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 88% | 56,289 psi | 88% | 2907 fps | 99.6% |
| SNPE Vectan Tubal 8000 | <<locked>> | 94% | 54,781 psi | 86% | 3005 fps | 98.7% |
| Somchem S355 | <<locked>> | 84% | 55,796 psi | 87% | 2933 fps | 100% |
| Somchem S361 | <<locked>> | 92% | 55,811 psi | 87% | 2936 fps | 97% |
| Somchem S365 | <<locked>> | 90% | 53,940 psi | 85% | 2969 fps | 100% |
| Somchem S385 | <<locked>> | 94% | 55,724 psi | 87% | 2982 fps | 99.3% |
| Vihtavuori N150 | <<locked>> | 86% | 57,029 psi | 89% | 2904 fps | 100% |
| Vihtavuori N160 | <<locked>> | 88% | 56,014 psi | 88% | 2963 fps | 100% |
| Vihtavuori N165 | <<locked>> | 98% | 55,201 psi | 87% | 2959 fps | 99% |
| Vihtavuori N540 | <<locked>> | 82% | 57,580 psi | 90% | 2900 fps | 100% |
| Vihtavuori N550 | <<locked>> | 88% | 55,245 psi | 87% | 2966 fps | 100% |
| Vihtavuori N555 | <<locked>> | 96% | 57,087 psi | 89% | 3038 fps | 100% |
| Vihtavuori N560 | <<locked>> | 96% | 57,145 psi | 90% | 3100 fps | 97.6% |
| Vihtavuori N565ᴾ | <<locked>> | 100% | 52,968 psi | 83% | 3012 fps | 97% |
| Winchester 6.5 StaBALL | <<locked>> | 88% | 55,637 psi | 87% | 2923 fps | 100% |
| Winchester 760 | <<locked>> | 88% | 57,667 psi | 90% | 3041 fps | 99.7% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 55,172 psi | 86% | 3143 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 96% | 55,898 psi | 88% | 2979 fps | 98.7% |
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 2700 | <<locked>> | 80% | 54,157 psi | 85% | 2884 fps | 99% |
| Accurate 3100 | <<locked>> | 82% | 33,591 psi | 53% | 2536 fps | 95.6% |
| Accurate 4350 | <<locked>> | 80% | 42,264 psi | 66% | 2749 fps | 99.3% |
| Accurate High Country | 76.7 gr | 88% | 44,817 psi | 70% | 2890 fps | 95.3% |
| Accurate MAGPRO | <<locked>> | 92% | 48,849 psi | 77% | 2956 fps | 95% |
| ADI AR 2208 | <<locked>> | 80% | 50,459 psi | 79% | 2844 fps | 100% |
| ADI AR 2209 | <<locked>> | 84% | 40,379 psi | 63% | 2726 fps | 95% |
| ADI AR 2213 | <<locked>> | 92% | 47,123 psi | 74% | 2900 fps | 95.6% |
| ADI AR 2225 | <<locked>> | 98% | 37,608 psi | 59% | 2736 fps | 96.1% |
| Alliant Power Pro Varmint | <<locked>> | 84% | 40,698 psi | 64% | 2730 fps | 95.1% |
| Alliant Power Pro Varmint | <<locked>> | 84% | 40,698 psi | 64% | 2730 fps | 95.1% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 51,503 psi | 81% | 2871 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 80% | 40,524 psi | 64% | 2756 fps | 99.4% |
| Alliant Reloder-17 | <<locked>> | 80% | 46,702 psi | 73% | 2887 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 84% | 40,292 psi | 63% | 2723 fps | 95% |
| Alliant Reloder-22 | <<locked>> | 88% | 41,017 psi | 64% | 2779 fps | 95.5% |
| Alliant Reloder-23 | <<locked>> | 80% | 30,023 psi | 47% | 2503 fps | 97.8% |
| Alliant Reloder-25 | <<locked>> | 86% | 31,981 psi | 50% | 2575 fps | 95.4% |
| Alliant Reloder-26 | 71.8 gr | 80% | 32,518 psi | 51% | 2628 fps | 96.6% |
| Bofors RP15 | <<locked>> | 90% | 40,480 psi | 63% | 2766 fps | 95.1% |
| Bofors RP3 | <<locked>> | 80% | 52,257 psi | 82% | 2887 fps | 100% |
| Bofors RP30 | <<locked>> | 98% | 43,236 psi | 68% | 2858 fps | 95.3% |
| Bofors RP5 | <<locked>> | 88% | 41,017 psi | 64% | 2779 fps | 95.5% |
| Bofors RP7 | <<locked>> | 80% | 45,585 psi | 71% | 2762 fps | 97.7% |
| Hodgdon H1000 | <<locked>> | 96% | 43,323 psi | 68% | 2812 fps | 95.4% |
| Hodgdon H380 | <<locked>> | 80% | 52,315 psi | 82% | 2900 fps | 100% |
| Hodgdon H414 | <<locked>> | 80% | 43,947 psi | 69% | 2795 fps | 97.8% |
| Hodgdon H4350 | <<locked>> | 80% | 46,659 psi | 73% | 2818 fps | 97.2% |
| Hodgdon H4831 | <<locked>> | 90% | 47,137 psi | 74% | 2844 fps | 95% |
| Hodgdon H4831 SC | <<locked>> | 92% | 49,443 psi | 77% | 2887 fps | 95.6% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 38,218 psi | 60% | 2644 fps | 99.7% |
| Hodgdon Retumbo | <<locked>> | 94% | 40,495 psi | 63% | 2848 fps | 95.8% |
| Hodgdon Superformance | <<locked>> | 80% | 43,047 psi | 67% | 2812 fps | 97.3% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,528 psi | 43% | 1670 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 53,113 psi | 83% | 2881 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 40,988 psi | 64% | 2684 fps | 96.5% |
| IMR 4451 Enduron | <<locked>> | 80% | 46,891 psi | 73% | 2789 fps | 98.3% |
| IMR 4831 | <<locked>> | 80% | 40,422 psi | 63% | 2700 fps | 99.1% |
| IMR 4955 Enduron | <<locked>> | 90% | 48,849 psi | 77% | 2844 fps | 95.7% |
| IMR 7828 SSC | <<locked>> | 92% | 45,150 psi | 71% | 2871 fps | 95.1% |
| Lovex S062 | <<locked>> | 80% | 53,621 psi | 84% | 2874 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 44,382 psi | 70% | 2736 fps | 98.9% |
| Lovex S070 | <<locked>> | 80% | 42,772 psi | 67% | 2723 fps | 97.7% |
| Lovex S071 | <<locked>> | 86% | 32,750 psi | 51% | 2513 fps | 95.2% |
| Norma 204 | <<locked>> | 80% | 40,814 psi | 64% | 2717 fps | 95% |
| Norma MRP | 73.2 gr | 84% | 37,492 psi | 59% | 2726 fps | 95.7% |
| Norma URP | <<locked>> | 80% | 41,684 psi | 65% | 2743 fps | 99.2% |
| Ramshot Grand | <<locked>> | 92% | 45,150 psi | 71% | 2884 fps | 95.6% |
| Ramshot Hunter | <<locked>> | 80% | 40,538 psi | 64% | 2730 fps | 97.7% |
| Ramshot Magnum | <<locked>> | 90% | 37,434 psi | 59% | 2687 fps | 95% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,036 psi | 44% | 1709 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 52,243 psi | 82% | 2887 fps | 99.5% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 49,545 psi | 78% | 2936 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 42,090 psi | 66% | 2769 fps | 99.1% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 40,393 psi | 63% | 2776 fps | 98.7% |
| ReloadSwiss RS 76 | <<locked>> | 92% | 37,449 psi | 59% | 2762 fps | 95.8% |
| Rottweil R 903 | <<locked>> | 80% | 49,313 psi | 77% | 2835 fps | 100% |
| Rottweil R 904 | <<locked>> | 86% | 44,788 psi | 70% | 2772 fps | 95.2% |
| Rottweil R 905 | <<locked>> | 84% | 39,566 psi | 62% | 2707 fps | 95% |
| Rottweil R 907 | <<locked>> | 80% | 45,585 psi | 71% | 2762 fps | 97.7% |
| Shooters World Long Rifle | <<locked>> | 80% | 44,382 psi | 70% | 2736 fps | 98.9% |
| Shooters World Precision | <<locked>> | 80% | 53,621 psi | 84% | 2874 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 42,772 psi | 67% | 2723 fps | 97.7% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 50,546 psi | 79% | 2887 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 49,821 psi | 78% | 2723 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 43,410 psi | 68% | 2680 fps | 97.7% |
| SNPE Vectan Tubal 8000 | <<locked>> | 86% | 42,003 psi | 66% | 2766 fps | 95.8% |
| Somchem S355 | <<locked>> | 80% | 49,153 psi | 77% | 2828 fps | 100% |
| Somchem S361 | <<locked>> | 88% | 48,979 psi | 77% | 2818 fps | 95.5% |
| Somchem S365 | <<locked>> | 80% | 38,305 psi | 60% | 2697 fps | 100% |
| Somchem S385 | <<locked>> | 82% | 37,608 psi | 59% | 2631 fps | 95.3% |
| Vihtavuori N150 | <<locked>> | 80% | 47,137 psi | 74% | 2753 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 43,062 psi | 67% | 2740 fps | 99.4% |
| Vihtavuori N165 | <<locked>> | 88% | 39,740 psi | 62% | 2674 fps | 95.6% |
| Vihtavuori N540 | <<locked>> | 80% | 54,070 psi | 85% | 2851 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 42,395 psi | 66% | 2736 fps | 99.2% |
| Vihtavuori N555 | <<locked>> | 80% | 33,663 psi | 53% | 2585 fps | 97.9% |
| Vihtavuori N560 | <<locked>> | 90% | 46,485 psi | 73% | 2907 fps | 95% |
| Vihtavuori N565 | <<locked>> | 96% | 46,050 psi | 72% | 2884 fps | 95.3% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 42,119 psi | 66% | 2703 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 44,092 psi | 69% | 2799 fps | 97.8% |
| Winchester StaBALL HD | <<locked>> | 80% | 26,687 psi | 42% | 2490 fps | 97.2% |
| Winchester Supreme 780 | <<locked>> | 88% | 42,192 psi | 66% | 2730 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 83 powders for .300 Weath. Mag. loaded with the .308 | 171gr | Viper Bullets Bush Gold. Winchester StaBALL HD delivers the highest muzzle velocity at 3,143 fps; across all powders the maximum-charge window runs from 1,867 fps to 3,143 fps. ADI AR 2225 gives the best case fill at 100 %, and 83 of the 83 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (440 MPa), the top charges use 58–90 %, leaving at least 10 % headroom. The 171.0 gr projectile in 0.308" calls for a 1:15.0 twist; slower twists will usually not stabilise this weight. ADI AR 2225, 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. Alliant Reloder-26, Accurate High Country, Norma MRP rank at the top here: for .300 Weath. Mag. with the .308 | 171gr | Viper Bullets Bush Gold 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.