Load Specifications
Load data in caliber .300 Weath. Mag. with .308 | 155gr | Sierra MatchKing bullet and 86 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.
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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 2495 | <<locked>> | 82% | 57,246 psi | 90% | 2999 fps | 100% |
| Accurate 2700 | <<locked>> | 82% | 54,636 psi | 86% | 3015 fps | 98.3% |
| Accurate 3100ᴾ | <<locked>> | 100% | 57,319 psi | 90% | 3123 fps | 99.7% |
| Accurate 4064 | <<locked>> | 82% | 54,186 psi | 85% | 3005 fps | 100% |
| Accurate 4350 | <<locked>> | 90% | 55,419 psi | 87% | 3120 fps | 100% |
| ADI AR 2208 | <<locked>> | 86% | 57,609 psi | 90% | 3094 fps | 100% |
| ADI AR 2209 | <<locked>> | 96% | 56,260 psi | 88% | 3159 fps | 97.9% |
| ADI AR 2213ᴾ | <<locked>> | 100% | 57,725 psi | 90% | 3215 fps | 97.1% |
| Alliant Power Pro 2000-MR | <<locked>> | 82% | 57,319 psi | 90% | 3222 fps | 100% |
| Alliant Reloder- TS 15.5 | <<locked>> | 84% | 55,085 psi | 86% | 3064 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 82% | 55,100 psi | 86% | 3084 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 92% | 55,912 psi | 88% | 3179 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 88% | 57,493 psi | 90% | 3202 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 96% | 55,608 psi | 87% | 3146 fps | 97.9% |
| Alliant Reloder-22ᴾ | <<locked>> | 100% | 56,927 psi | 89% | 3209 fps | 98.3% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 53,940 psi | 85% | 3140 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 46,615 psi | 73% | 3054 fps | 99.1% |
| Alliant Reloder-26 | <<locked>> | 96% | 54,157 psi | 85% | 3222 fps | 100% |
| Bofors RP15ᴾ | <<locked>> | 100% | 52,185 psi | 82% | 3123 fps | 97.3% |
| Bofors RP3 | <<locked>> | 84% | 55,985 psi | 88% | 3081 fps | 100% |
| Bofors RP5ᴾ | <<locked>> | 100% | 56,927 psi | 89% | 3209 fps | 98.3% |
| Bofors RP7 | <<locked>> | 88% | 55,201 psi | 87% | 3061 fps | 98.6% |
| Hodgdon H380 | <<locked>> | 84% | 56,333 psi | 88% | 3100 fps | 99.9% |
| Hodgdon H414 | <<locked>> | 90% | 57,522 psi | 90% | 3173 fps | 99.3% |
| Hodgdon H4350 | <<locked>> | 88% | 56,855 psi | 89% | 3127 fps | 98.3% |
| Hodgdon H4831 SC | <<locked>> | 98% | 56,652 psi | 89% | 3133 fps | 96.2% |
| Hodgdon Hybrid 100V | <<locked>> | 94% | 56,492 psi | 89% | 3097 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 82% | 57,580 psi | 90% | 3133 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 45,803 psi | 72% | 3084 fps | 96.4% |
| Hodgdon Superformance | <<locked>> | 88% | 53,838 psi | 84% | 3140 fps | 98.6% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,579 psi | 57% | 1959 fps | 100% |
| IMR 4064 | <<locked>> | 84% | 56,884 psi | 89% | 3074 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 82% | 55,941 psi | 88% | 3054 fps | 99% |
| IMR 4350 | <<locked>> | 92% | 56,304 psi | 88% | 3097 fps | 98.8% |
| IMR 4451 Enduron | <<locked>> | 88% | 56,811 psi | 89% | 3091 fps | 99.1% |
| IMR 4831 | <<locked>> | 92% | 55,811 psi | 87% | 3110 fps | 100% |
| IMR 4895 | <<locked>> | 82% | 56,536 psi | 89% | 3114 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 96% | 55,593 psi | 87% | 3084 fps | 96.2% |
| IMR 7828 SSCᴾ | <<locked>> | 100% | 55,230 psi | 87% | 3186 fps | 96.6% |
| Lovex S062 | <<locked>> | 84% | 57,290 psi | 90% | 3068 fps | 100% |
| Lovex S065 | <<locked>> | 90% | 57,014 psi | 89% | 3087 fps | 99.7% |
| Lovex S070 | <<locked>> | 90% | 55,129 psi | 86% | 3077 fps | 99.1% |
| Lovex S071ᴾ | <<locked>> | 100% | 47,543 psi | 75% | 2956 fps | 98.5% |
| Norma 203B | <<locked>> | 82% | 54,389 psi | 85% | 3068 fps | 100% |
| Norma 204 | <<locked>> | 92% | 57,493 psi | 90% | 3153 fps | 98% |
| Norma MRP | <<locked>> | 98% | 56,710 psi | 89% | 3238 fps | 99.2% |
| Norma URP | <<locked>> | 92% | 57,508 psi | 90% | 3156 fps | 100% |
| Ramshot Big Game | <<locked>> | 82% | 55,274 psi | 87% | 3094 fps | 100% |
| Ramshot Grandᴾ | <<locked>> | 100% | 55,709 psi | 87% | 3205 fps | 97.1% |
| Ramshot Hunter | <<locked>> | 92% | 56,463 psi | 88% | 3156 fps | 99.6% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 50,009 psi | 78% | 3068 fps | 97.6% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,173 psi | 58% | 2001 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 84% | 56,144 psi | 88% | 3081 fps | 99.4% |
| ReloadSwiss RS 60 | <<locked>> | 86% | 57,000 psi | 89% | 3196 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 90% | 55,303 psi | 87% | 3136 fps | 99.9% |
| ReloadSwiss RS 70 | <<locked>> | 92% | 57,580 psi | 90% | 3228 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 45,948 psi | 72% | 3081 fps | 97.6% |
| Rottweil R 902 | <<locked>> | 82% | 55,811 psi | 87% | 3031 fps | 100% |
| Rottweil R 903 | <<locked>> | 86% | 56,086 psi | 88% | 3077 fps | 100% |
| Rottweil R 904 | <<locked>> | 94% | 54,215 psi | 85% | 3068 fps | 96.4% |
| Rottweil R 905 | <<locked>> | 96% | 54,897 psi | 86% | 3130 fps | 97.9% |
| Rottweil R 907 | <<locked>> | 88% | 55,201 psi | 87% | 3061 fps | 98.6% |
| Shooters World Long Rifle | <<locked>> | 90% | 57,014 psi | 89% | 3087 fps | 99.7% |
| Shooters World Precision | <<locked>> | 84% | 57,290 psi | 90% | 3068 fps | 100% |
| Shooters World SW4350 | <<locked>> | 90% | 55,129 psi | 86% | 3077 fps | 99.1% |
| SNPE Vectan SP 11 | <<locked>> | 84% | 53,983 psi | 85% | 3081 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 86% | 56,797 psi | 89% | 2959 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 90% | 56,681 psi | 89% | 3035 fps | 99.1% |
| SNPE Vectan Tubal 8000 | <<locked>> | 96% | 54,418 psi | 85% | 3127 fps | 97.8% |
| Somchem S355 | <<locked>> | 86% | 55,854 psi | 88% | 3071 fps | 100% |
| Somchem S361 | <<locked>> | 94% | 56,072 psi | 88% | 3058 fps | 96% |
| Somchem S365 | <<locked>> | 94% | 57,246 psi | 90% | 3159 fps | 100% |
| Somchem S385 | <<locked>> | 96% | 55,637 psi | 87% | 3107 fps | 98.6% |
| Vihtavuori N135 | <<locked>> | 82% | 56,159 psi | 88% | 2986 fps | 100% |
| Vihtavuori N140 | <<locked>> | 82% | 56,347 psi | 88% | 3002 fps | 100% |
| Vihtavuori N150 | <<locked>> | 88% | 57,377 psi | 90% | 3045 fps | 100% |
| Vihtavuori N160 | <<locked>> | 90% | 56,057 psi | 88% | 3097 fps | 100% |
| Vihtavuori N165ᴾ | <<locked>> | 100% | 55,013 psi | 86% | 3081 fps | 98.3% |
| Vihtavuori N540 | <<locked>> | 82% | 54,491 psi | 85% | 2992 fps | 100% |
| Vihtavuori N550 | <<locked>> | 90% | 55,100 psi | 86% | 3097 fps | 99.9% |
| Vihtavuori N555 | <<locked>> | 98% | 56,376 psi | 88% | 3166 fps | 100% |
| Vihtavuori N560 | <<locked>> | 98% | 56,855 psi | 89% | 3225 fps | 96.6% |
| Winchester 6.5 StaBALL | <<locked>> | 90% | 55,608 psi | 87% | 3054 fps | 100% |
| Winchester 760 | <<locked>> | 90% | 57,522 psi | 90% | 3173 fps | 99.3% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 49,487 psi | 78% | 3199 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 98% | 55,796 psi | 87% | 3100 fps | 97.8% |
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 2495 | <<locked>> | 80% | 53,795 psi | 84% | 2949 fps | 100% |
| Accurate 2700 | <<locked>> | 80% | 51,227 psi | 80% | 2956 fps | 97.7% |
| Accurate 3100 | <<locked>> | 86% | 35,418 psi | 56% | 2694 fps | 95.1% |
| Accurate 4064 | <<locked>> | 80% | 50,995 psi | 80% | 2956 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 39,247 psi | 62% | 2808 fps | 98% |
| ADI AR 2208 | <<locked>> | 80% | 47,805 psi | 75% | 2927 fps | 99.7% |
| ADI AR 2209 | <<locked>> | 90% | 46,180 psi | 72% | 2972 fps | 95.6% |
| ADI AR 2213 | <<locked>> | 96% | 50,430 psi | 79% | 3081 fps | 95.3% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 53,316 psi | 84% | 3159 fps | 100% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 48,559 psi | 76% | 2956 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 51,822 psi | 81% | 3028 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 80% | 37,884 psi | 59% | 2815 fps | 98.1% |
| Alliant Reloder-17 | <<locked>> | 80% | 43,308 psi | 68% | 2953 fps | 99.9% |
| Alliant Reloder-19 | <<locked>> | 90% | 45,847 psi | 72% | 2963 fps | 95.7% |
| Alliant Reloder-22 | <<locked>> | 92% | 43,395 psi | 68% | 2953 fps | 95% |
| Alliant Reloder-23 | <<locked>> | 80% | 27,920 psi | 44% | 2546 fps | 95.5% |
| Alliant Reloder-25 | <<locked>> | 92% | 35,984 psi | 56% | 2795 fps | 96% |
| Alliant Reloder-26 | 74.2 gr | 82% | 32,140 psi | 50% | 2726 fps | 95% |
| Bofors RP15 | <<locked>> | 96% | 45,629 psi | 72% | 2999 fps | 95.6% |
| Bofors RP3 | <<locked>> | 80% | 49,037 psi | 77% | 2966 fps | 100% |
| Bofors RP5 | <<locked>> | 92% | 43,395 psi | 68% | 2953 fps | 95% |
| Bofors RP7 | <<locked>> | 80% | 42,888 psi | 67% | 2825 fps | 95.9% |
| Hodgdon H380 | <<locked>> | 80% | 49,240 psi | 77% | 2976 fps | 99.4% |
| Hodgdon H414 | <<locked>> | 80% | 41,002 psi | 64% | 2854 fps | 95.9% |
| Hodgdon H4350 | <<locked>> | 80% | 43,918 psi | 69% | 2881 fps | 95.4% |
| Hodgdon H4831 SC | <<locked>> | 96% | 52,910 psi | 83% | 3071 fps | 95.3% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 35,534 psi | 56% | 2703 fps | 98.6% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 53,940 psi | 85% | 3077 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 98% | 42,902 psi | 67% | 3018 fps | 95.3% |
| Hodgdon Superformance | <<locked>> | 80% | 40,132 psi | 63% | 2864 fps | 95.2% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,296 psi | 43% | 1752 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 50,299 psi | 79% | 2966 fps | 99.9% |
| IMR 4166 Enduron | <<locked>> | 80% | 52,504 psi | 82% | 2995 fps | 98.6% |
| IMR 4350 | <<locked>> | 82% | 41,147 psi | 64% | 2802 fps | 95.4% |
| IMR 4451 Enduron | <<locked>> | 80% | 44,382 psi | 70% | 2861 fps | 96.8% |
| IMR 4831 | <<locked>> | 80% | 37,536 psi | 59% | 2753 fps | 97.7% |
| IMR 4895 | <<locked>> | 80% | 53,185 psi | 83% | 3058 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 94% | 52,156 psi | 82% | 3022 fps | 95.3% |
| IMR 7828 SSC | <<locked>> | 98% | 51,605 psi | 81% | 3117 fps | 95.8% |
| Lovex S062 | <<locked>> | 80% | 50,531 psi | 79% | 2959 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 41,843 psi | 66% | 2805 fps | 97.5% |
| Lovex S070 | <<locked>> | 80% | 40,074 psi | 63% | 2782 fps | 95.9% |
| Lovex S071 | <<locked>> | 92% | 36,767 psi | 58% | 2730 fps | 95.6% |
| Norma 203B | <<locked>> | 80% | 51,184 psi | 80% | 3015 fps | 100% |
| Norma 204 | <<locked>> | 86% | 46,847 psi | 73% | 2963 fps | 95.7% |
| Norma MRP | 77.3 gr | 88% | 39,784 psi | 62% | 2897 fps | 95.3% |
| Norma URP | <<locked>> | 80% | 38,769 psi | 61% | 2799 fps | 97.8% |
| Ramshot Big Game | <<locked>> | 80% | 51,561 psi | 81% | 3035 fps | 100% |
| Ramshot Grand | <<locked>> | 96% | 48,138 psi | 75% | 3061 fps | 95.2% |
| Ramshot Hunter | <<locked>> | 80% | 37,724 psi | 59% | 2782 fps | 95.8% |
| Ramshot Magnum | <<locked>> | 96% | 43,018 psi | 67% | 2923 fps | 95.7% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,746 psi | 43% | 1791 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 49,255 psi | 77% | 2956 fps | 98.5% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 46,006 psi | 72% | 3012 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 38,986 psi | 61% | 2825 fps | 97.7% |
| ReloadSwiss RS 70 | 71.7 gr | 80% | 37,608 psi | 59% | 2825 fps | 96.9% |
| ReloadSwiss RS 76 | <<locked>> | 96% | 39,842 psi | 62% | 2930 fps | 95.3% |
| Rottweil R 902 | <<locked>> | 80% | 52,272 psi | 82% | 2972 fps | 100% |
| Rottweil R 903 | <<locked>> | 80% | 46,064 psi | 72% | 2907 fps | 100% |
| Rottweil R 904 | <<locked>> | 92% | 50,952 psi | 80% | 3012 fps | 95.7% |
| Rottweil R 905 | <<locked>> | 90% | 44,947 psi | 70% | 2943 fps | 95.6% |
| Rottweil R 907 | <<locked>> | 80% | 42,888 psi | 67% | 2825 fps | 95.9% |
| Shooters World Long Rifle | <<locked>> | 80% | 41,843 psi | 66% | 2805 fps | 97.5% |
| Shooters World Precision | <<locked>> | 80% | 50,531 psi | 79% | 2959 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 40,074 psi | 63% | 2782 fps | 95.9% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 47,413 psi | 74% | 2966 fps | 99.9% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 47,108 psi | 74% | 2808 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 40,973 psi | 64% | 2743 fps | 96.1% |
| SNPE Vectan Tubal 8000 | <<locked>> | 90% | 44,570 psi | 70% | 2936 fps | 95.4% |
| Somchem S355 | <<locked>> | 80% | 46,325 psi | 73% | 2907 fps | 99.9% |
| Somchem S361 | <<locked>> | 92% | 52,431 psi | 82% | 2995 fps | 95.2% |
| Somchem S365 | <<locked>> | 80% | 35,331 psi | 55% | 2753 fps | 99.5% |
| Somchem S385 | <<locked>> | 88% | 42,743 psi | 67% | 2864 fps | 95.8% |
| Vihtavuori N135 | <<locked>> | 80% | 52,736 psi | 83% | 2936 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 52,852 psi | 83% | 2949 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 44,222 psi | 69% | 2831 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 40,277 psi | 63% | 2802 fps | 98.2% |
| Vihtavuori N165 | <<locked>> | 92% | 42,177 psi | 66% | 2841 fps | 95.2% |
| Vihtavuori N540 | <<locked>> | 80% | 51,140 psi | 80% | 2943 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 39,668 psi | 62% | 2799 fps | 97.9% |
| Vihtavuori N555 | <<locked>> | 80% | 30,879 psi | 48% | 2628 fps | 95.7% |
| Vihtavuori N560 | <<locked>> | 96% | 52,924 psi | 83% | 3156 fps | 95.7% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 39,378 psi | 62% | 2766 fps | 99.6% |
| Winchester 760 | <<locked>> | 80% | 41,176 psi | 65% | 2858 fps | 96% |
| Winchester StaBALL HD | <<locked>> | 82% | 26,397 psi | 41% | 2569 fps | 95.1% |
| Winchester Supreme 780 | <<locked>> | 92% | 45,150 psi | 71% | 2907 fps | 95.4% |
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 94 powders for .300 Weath. Mag. loaded with the .308 | 155gr | Sierra MatchKing. Norma MRP delivers the highest muzzle velocity at 3,238 fps; across all powders the maximum-charge window runs from 1,959 fps to 3,238 fps. Accurate 3100 gives the best case fill at 100 %, and 94 of the 94 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 155.0 gr projectile in 0.308" calls for a 1:14.5 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 | 155gr | Sierra MatchKing 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.