Load Specifications
Load data in caliber .300 Weath. Mag. with .308 | 165gr | Geco STAR bullet and 89 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Alliant Reloder-26, Norma MRP and ReloadSwiss RS 70.
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% | 56,420 psi | 88% | 2900 fps | 100% |
| Accurate 2700 | <<locked>> | 82% | 54,404 psi | 85% | 2930 fps | 98.6% |
| Accurate 3100ᴾ | <<locked>> | 100% | 56,492 psi | 89% | 3028 fps | 99.8% |
| Accurate 4064 | <<locked>> | 84% | 56,971 psi | 89% | 2963 fps | 100% |
| Accurate 4350 | <<locked>> | 90% | 54,752 psi | 86% | 3025 fps | 100% |
| Accurate MAGPRO | <<locked>> | 98% | 55,419 psi | 87% | 3117 fps | 96.1% |
| ADI AR 2208 | <<locked>> | 86% | 57,392 psi | 90% | 3002 fps | 100% |
| ADI AR 2209 | <<locked>> | 96% | 56,086 psi | 88% | 3074 fps | 98.3% |
| ADI AR 2213ᴾ | <<locked>> | 100% | 57,392 psi | 90% | 3127 fps | 97.5% |
| Alliant Power Pro 2000-MR | <<locked>> | 82% | 57,174 psi | 90% | 3130 fps | 100% |
| Alliant Reloder- TS 15.5 | <<locked>> | 84% | 54,708 psi | 86% | 2969 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 82% | 54,679 psi | 86% | 2989 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 92% | 55,854 psi | 88% | 3087 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 88% | 57,305 psi | 90% | 3107 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 96% | 55,390 psi | 87% | 3058 fps | 98.2% |
| Alliant Reloder-22ᴾ | <<locked>> | 100% | 56,521 psi | 89% | 3120 fps | 98.6% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 53,519 psi | 84% | 3045 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 46,253 psi | 72% | 2966 fps | 99.4% |
| Alliant Reloder-26 | <<locked>> | 96% | 53,737 psi | 84% | 3130 fps | 100% |
| Bofors RP15ᴾ | <<locked>> | 100% | 51,822 psi | 81% | 3038 fps | 97.6% |
| Bofors RP3 | <<locked>> | 84% | 55,332 psi | 87% | 2982 fps | 100% |
| Bofors RP5ᴾ | <<locked>> | 100% | 56,521 psi | 89% | 3120 fps | 98.6% |
| Bofors RP7 | <<locked>> | 88% | 54,781 psi | 86% | 2969 fps | 98.8% |
| Hodgdon H380 | <<locked>> | 84% | 55,883 psi | 88% | 3005 fps | 100% |
| Hodgdon H414 | <<locked>> | 90% | 57,072 psi | 89% | 3081 fps | 99.5% |
| Hodgdon H4350 | <<locked>> | 88% | 56,536 psi | 89% | 3035 fps | 98.6% |
| Hodgdon H4831 | <<locked>> | 98% | 57,609 psi | 90% | 3068 fps | 96.9% |
| Hodgdon H4831 SC | <<locked>> | 98% | 56,405 psi | 88% | 3051 fps | 96.6% |
| Hodgdon Hybrid 100V | <<locked>> | 94% | 55,956 psi | 88% | 3005 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 82% | 57,232 psi | 90% | 3038 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 45,266 psi | 71% | 2999 fps | 96.9% |
| Hodgdon Superformance | <<locked>> | 88% | 53,679 psi | 84% | 3054 fps | 98.9% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,405 psi | 57% | 1890 fps | 100% |
| Hodgdon VARGET | <<locked>> | 82% | 57,595 psi | 90% | 3002 fps | 100% |
| IMR 4064 | <<locked>> | 84% | 56,753 psi | 89% | 2982 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 82% | 55,680 psi | 87% | 2966 fps | 99.3% |
| IMR 4350 | <<locked>> | 92% | 56,115 psi | 88% | 3009 fps | 99% |
| IMR 4451 Enduron | <<locked>> | 88% | 56,594 psi | 89% | 3002 fps | 99.3% |
| IMR 4831 | <<locked>> | 92% | 55,216 psi | 87% | 3015 fps | 100% |
| IMR 4895 | <<locked>> | 82% | 56,101 psi | 88% | 3018 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 96% | 55,390 psi | 87% | 2995 fps | 96.6% |
| IMR 7828 SSCᴾ | <<locked>> | 100% | 54,781 psi | 86% | 3097 fps | 97.1% |
| Lovex S062 | <<locked>> | 84% | 56,768 psi | 89% | 2972 fps | 100% |
| Lovex S065 | <<locked>> | 90% | 56,652 psi | 89% | 2995 fps | 99.9% |
| Lovex S070 | <<locked>> | 90% | 54,592 psi | 86% | 2986 fps | 99.3% |
| Lovex S071ᴾ | <<locked>> | 100% | 46,775 psi | 73% | 2867 fps | 98.7% |
| Norma 203B | <<locked>> | 84% | 57,725 psi | 90% | 3035 fps | 100% |
| Norma 204 | <<locked>> | 92% | 57,203 psi | 90% | 3068 fps | 98.3% |
| Norma MRP | <<locked>> | 98% | 56,362 psi | 88% | 3146 fps | 99.4% |
| Norma URP | <<locked>> | 92% | 57,188 psi | 90% | 3064 fps | 100% |
| Ramshot Big Game | <<locked>> | 82% | 54,998 psi | 86% | 3002 fps | 100% |
| Ramshot Grandᴾ | <<locked>> | 100% | 55,448 psi | 87% | 3117 fps | 97.6% |
| Ramshot Hunter | <<locked>> | 92% | 56,159 psi | 88% | 3068 fps | 99.7% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 49,501 psi | 78% | 2979 fps | 98% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 36,999 psi | 58% | 1932 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 84% | 55,651 psi | 87% | 2986 fps | 99.6% |
| ReloadSwiss RS 60 | <<locked>> | 86% | 56,507 psi | 89% | 3097 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 90% | 54,824 psi | 86% | 3045 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 92% | 57,261 psi | 90% | 3136 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 45,455 psi | 71% | 2999 fps | 98.1% |
| Rottweil R 902 | <<locked>> | 82% | 55,085 psi | 86% | 2930 fps | 100% |
| Rottweil R 903 | <<locked>> | 86% | 55,651 psi | 87% | 2986 fps | 100% |
| Rottweil R 904 | <<locked>> | 96% | 57,624 psi | 90% | 3041 fps | 97.6% |
| Rottweil R 905 | <<locked>> | 96% | 54,592 psi | 86% | 3041 fps | 98.2% |
| Rottweil R 907 | <<locked>> | 88% | 54,781 psi | 86% | 2969 fps | 98.8% |
| Shooters World Long Rifle | <<locked>> | 90% | 56,652 psi | 89% | 2995 fps | 99.9% |
| Shooters World Precision | <<locked>> | 84% | 56,768 psi | 89% | 2972 fps | 100% |
| Shooters World SW4350 | <<locked>> | 90% | 54,592 psi | 86% | 2986 fps | 99.3% |
| SNPE Vectan SP 11 | <<locked>> | 86% | 57,421 psi | 90% | 3045 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 86% | 56,434 psi | 88% | 2864 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 90% | 56,217 psi | 88% | 2949 fps | 99.3% |
| SNPE Vectan Tubal 8000 | <<locked>> | 96% | 54,128 psi | 85% | 3038 fps | 98.2% |
| Somchem S355 | <<locked>> | 86% | 55,492 psi | 87% | 2976 fps | 100% |
| Somchem S361 | <<locked>> | 94% | 55,782 psi | 87% | 2976 fps | 96.5% |
| Somchem S365 | <<locked>> | 94% | 56,797 psi | 89% | 3064 fps | 100% |
| Somchem S385 | <<locked>> | 96% | 55,056 psi | 86% | 3015 fps | 98.9% |
| Vihtavuori N135 | <<locked>> | 82% | 55,666 psi | 87% | 2890 fps | 100% |
| Vihtavuori N140 | <<locked>> | 82% | 55,927 psi | 88% | 2907 fps | 100% |
| Vihtavuori N150 | <<locked>> | 88% | 57,000 psi | 89% | 2953 fps | 100% |
| Vihtavuori N160 | <<locked>> | 90% | 55,666 psi | 87% | 3005 fps | 100% |
| Vihtavuori N165ᴾ | <<locked>> | 100% | 54,462 psi | 85% | 2992 fps | 98.5% |
| Vihtavuori N540 | <<locked>> | 82% | 54,157 psi | 85% | 2900 fps | 100% |
| Vihtavuori N550 | <<locked>> | 90% | 54,766 psi | 86% | 3009 fps | 100% |
| Vihtavuori N555 | <<locked>> | 98% | 55,666 psi | 87% | 3068 fps | 100% |
| Vihtavuori N560 | <<locked>> | 98% | 56,492 psi | 89% | 3136 fps | 97% |
| Winchester 6.5 StaBALL | <<locked>> | 90% | 55,448 psi | 87% | 2969 fps | 100% |
| Winchester 760 | <<locked>> | 90% | 57,334 psi | 90% | 3084 fps | 99.5% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 49,226 psi | 77% | 3110 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 98% | 55,332 psi | 87% | 3012 fps | 98.1% |
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% | 52,808 psi | 83% | 2851 fps | 100% |
| Accurate 2700 | <<locked>> | 80% | 50,894 psi | 80% | 2867 fps | 98.1% |
| Accurate 3100 | <<locked>> | 86% | 34,606 psi | 54% | 2605 fps | 95.4% |
| Accurate 4064 | <<locked>> | 80% | 50,082 psi | 78% | 2858 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 38,392 psi | 60% | 2713 fps | 98.3% |
| Accurate MAGPRO | <<locked>> | 96% | 51,372 psi | 81% | 3048 fps | 95.1% |
| ADI AR 2208 | <<locked>> | 80% | 47,456 psi | 74% | 2838 fps | 99.9% |
| ADI AR 2209 | <<locked>> | 88% | 42,859 psi | 67% | 2822 fps | 95.2% |
| ADI AR 2213 | <<locked>> | 96% | 49,995 psi | 78% | 2995 fps | 95.8% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 53,243 psi | 83% | 3068 fps | 100% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 48,124 psi | 75% | 2864 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 51,300 psi | 80% | 2933 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 80% | 37,463 psi | 59% | 2730 fps | 98.4% |
| Alliant Reloder-17 | <<locked>> | 80% | 42,801 psi | 67% | 2864 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 88% | 42,424 psi | 66% | 2812 fps | 95.1% |
| Alliant Reloder-22 | <<locked>> | 92% | 42,873 psi | 67% | 2864 fps | 95.5% |
| Alliant Reloder-23 | <<locked>> | 80% | 27,296 psi | 43% | 2461 fps | 95.9% |
| Alliant Reloder-25 | <<locked>> | 90% | 33,272 psi | 52% | 2651 fps | 95.3% |
| Alliant Reloder-26 | 72 gr | 82% | 31,531 psi | 49% | 2641 fps | 95.4% |
| Bofors RP15 | <<locked>> | 94% | 42,279 psi | 66% | 2848 fps | 95.1% |
| Bofors RP3 | <<locked>> | 80% | 48,341 psi | 76% | 2871 fps | 100% |
| Bofors RP5 | <<locked>> | 92% | 42,873 psi | 67% | 2864 fps | 95.5% |
| Bofors RP7 | <<locked>> | 80% | 42,380 psi | 66% | 2736 fps | 96.3% |
| Hodgdon H380 | <<locked>> | 80% | 48,689 psi | 76% | 2884 fps | 99.6% |
| Hodgdon H414 | <<locked>> | 80% | 40,553 psi | 64% | 2766 fps | 96.4% |
| Hodgdon H4350 | <<locked>> | 80% | 43,468 psi | 68% | 2795 fps | 95.8% |
| Hodgdon H4831 | <<locked>> | 94% | 50,183 psi | 79% | 2940 fps | 95.1% |
| Hodgdon H4831 SC | <<locked>> | 96% | 52,533 psi | 82% | 2986 fps | 95.8% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 35,012 psi | 55% | 2618 fps | 98.9% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 53,447 psi | 84% | 2982 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 98% | 42,221 psi | 66% | 2930 fps | 95.8% |
| Hodgdon Superformance | <<locked>> | 80% | 39,581 psi | 62% | 2776 fps | 95.6% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,151 psi | 43% | 1686 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 54,070 psi | 85% | 2949 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 49,937 psi | 78% | 2874 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 80% | 52,301 psi | 82% | 2910 fps | 98.9% |
| IMR 4350 | <<locked>> | 82% | 40,727 psi | 64% | 2720 fps | 95.8% |
| IMR 4451 Enduron | <<locked>> | 80% | 43,888 psi | 69% | 2772 fps | 97.2% |
| IMR 4831 | <<locked>> | 80% | 36,970 psi | 58% | 2667 fps | 98% |
| IMR 4895 | <<locked>> | 80% | 52,634 psi | 82% | 2963 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 92% | 48,631 psi | 76% | 2877 fps | 95% |
| IMR 7828 SSC | <<locked>> | 96% | 47,718 psi | 75% | 2963 fps | 95.2% |
| Lovex S062 | <<locked>> | 80% | 50,009 psi | 78% | 2864 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 41,321 psi | 65% | 2717 fps | 97.8% |
| Lovex S070 | <<locked>> | 80% | 39,494 psi | 62% | 2694 fps | 96.3% |
| Lovex S071 | <<locked>> | 90% | 33,591 psi | 53% | 2582 fps | 95% |
| Norma 203B | <<locked>> | 80% | 50,618 psi | 79% | 2920 fps | 100% |
| Norma 204 | <<locked>> | 84% | 43,250 psi | 68% | 2812 fps | 95.2% |
| Norma MRP | 75 gr | 88% | 39,305 psi | 62% | 2815 fps | 95.8% |
| Norma URP | <<locked>> | 80% | 38,290 psi | 60% | 2713 fps | 98.1% |
| Ramshot Big Game | <<locked>> | 80% | 51,358 psi | 80% | 2946 fps | 100% |
| Ramshot Grand | <<locked>> | 96% | 47,761 psi | 75% | 2976 fps | 95.7% |
| Ramshot Hunter | <<locked>> | 80% | 37,115 psi | 58% | 2697 fps | 96.2% |
| Ramshot Magnum | <<locked>> | 94% | 39,436 psi | 62% | 2772 fps | 95% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,586 psi | 43% | 1726 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 48,689 psi | 76% | 2867 fps | 98.7% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 45,527 psi | 71% | 2920 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 38,319 psi | 60% | 2733 fps | 98% |
| ReloadSwiss RS 70 | 69.6 gr | 80% | 37,231 psi | 58% | 2743 fps | 97.4% |
| ReloadSwiss RS 76 | <<locked>> | 96% | 39,117 psi | 61% | 2841 fps | 95.7% |
| Rottweil R 902 | <<locked>> | 80% | 51,866 psi | 81% | 2884 fps | 100% |
| Rottweil R 903 | <<locked>> | 80% | 45,469 psi | 71% | 2815 fps | 100% |
| Rottweil R 904 | <<locked>> | 90% | 47,282 psi | 74% | 2861 fps | 95.3% |
| Rottweil R 905 | <<locked>> | 88% | 41,539 psi | 65% | 2795 fps | 95.1% |
| Rottweil R 907 | <<locked>> | 80% | 42,380 psi | 66% | 2736 fps | 96.3% |
| Shooters World Long Rifle | <<locked>> | 80% | 41,321 psi | 65% | 2717 fps | 97.8% |
| Shooters World Precision | <<locked>> | 80% | 50,009 psi | 78% | 2864 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 39,494 psi | 62% | 2694 fps | 96.3% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 46,833 psi | 73% | 2871 fps | 99.9% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 46,804 psi | 73% | 2723 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 40,495 psi | 63% | 2661 fps | 96.5% |
| SNPE Vectan Tubal 8000 | <<locked>> | 90% | 44,063 psi | 69% | 2851 fps | 95.8% |
| Somchem S355 | <<locked>> | 80% | 45,774 psi | 72% | 2815 fps | 100% |
| Somchem S361 | <<locked>> | 92% | 51,996 psi | 81% | 2913 fps | 95.6% |
| Somchem S365 | <<locked>> | 80% | 34,824 psi | 55% | 2667 fps | 99.7% |
| Somchem S385 | <<locked>> | 86% | 39,436 psi | 62% | 2717 fps | 95.3% |
| Vihtavuori N135 | <<locked>> | 80% | 52,359 psi | 82% | 2844 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 52,489 psi | 82% | 2858 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 43,758 psi | 69% | 2740 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 39,697 psi | 62% | 2713 fps | 98.5% |
| Vihtavuori N165 | <<locked>> | 92% | 41,597 psi | 65% | 2756 fps | 95.6% |
| Vihtavuori N540 | <<locked>> | 80% | 50,662 psi | 79% | 2848 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 39,088 psi | 61% | 2710 fps | 98.1% |
| Vihtavuori N555 | <<locked>> | 80% | 30,168 psi | 47% | 2539 fps | 96% |
| Vihtavuori N560 | <<locked>> | 94% | 49,081 psi | 77% | 3002 fps | 95.2% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 38,928 psi | 61% | 2684 fps | 99.7% |
| Winchester 760 | <<locked>> | 80% | 40,698 psi | 64% | 2772 fps | 96.4% |
| Winchester StaBALL HD | <<locked>> | 82% | 25,672 psi | 40% | 2484 fps | 95.5% |
| Winchester Supreme 780 | <<locked>> | 92% | 44,672 psi | 70% | 2825 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 95 powders for .300 Weath. Mag. loaded with the .308 | 165gr | Geco STAR. Norma MRP delivers the highest muzzle velocity at 3,146 fps; across all powders the maximum-charge window runs from 1,890 fps to 3,146 fps. Accurate 3100 gives the best case fill at 100 %, and 95 of the 95 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 1:13.0 twist; slower twists will usually not stabilise this weight. Accurate 3100, ADI AR 2213, ADI AR 2217 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, Norma MRP, ReloadSwiss RS 70 rank at the top here: for .300 Weath. Mag. with the .308 | 165gr | Geco STAR they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, ADI AR 2217, ADI AR 2225, Baschieri & Pellagri 109 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.