Load Specifications
Load data in caliber .257 Weath. Mag. with .257 | 115gr | Berger VLD Target bullet and 72 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Hodgdon Retumbo, ReloadSwiss RS 76 and Accurate High Country.
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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Max Load - Barrel Length: 26"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 3100 | <<locked>> | 92% | 57,145 psi | 90% | 3169 fps | 100% |
| Accurate 4350 | <<locked>> | 82% | 54,128 psi | 85% | 3140 fps | 100% |
| Accurate High Country | <<locked>> | 88% | 55,013 psi | 86% | 3271 fps | 99.2% |
| Accurate MAGPRO | <<locked>> | 90% | 55,956 psi | 88% | 3274 fps | 98.5% |
| ADI AR 2209 | <<locked>> | 88% | 55,085 psi | 86% | 3205 fps | 99.6% |
| ADI AR 2213 | <<locked>> | 92% | 56,797 psi | 89% | 3274 fps | 99.3% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 55,056 psi | 86% | 3238 fps | 99.4% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 49,472 psi | 78% | 3192 fps | 100% |
| Alliant Power Pro Varmint | <<locked>> | 88% | 55,245 psi | 87% | 3202 fps | 99.6% |
| Alliant Reloder-16 | <<locked>> | 84% | 55,259 psi | 87% | 3202 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 88% | 54,621 psi | 86% | 3192 fps | 99.6% |
| Alliant Reloder-22 | <<locked>> | 92% | 57,058 psi | 89% | 3268 fps | 99.8% |
| Alliant Reloder-23 | <<locked>> | 92% | 54,853 psi | 86% | 3176 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 96% | 54,708 psi | 86% | 3248 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 88% | 55,550 psi | 87% | 3271 fps | 100% |
| Alliant Reloder-33ᴾ | <<locked>> | 100% | 52,170 psi | 82% | 3251 fps | 96.2% |
| Baschieri & Pellagri 109 | <<locked>> | 92% | 54,360 psi | 85% | 3163 fps | 96.7% |
| Bofors RP15 | <<locked>> | 94% | 56,231 psi | 88% | 3255 fps | 99.8% |
| Bofors RP30 | <<locked>> | 98% | 54,549 psi | 85% | 3251 fps | 99.4% |
| Bofors RP5 | <<locked>> | 92% | 57,058 psi | 89% | 3268 fps | 99.8% |
| Bofors RP7 | <<locked>> | 82% | 55,956 psi | 88% | 3140 fps | 99.9% |
| Hodgdon H1000 | <<locked>> | 98% | 56,666 psi | 89% | 3264 fps | 99.8% |
| Hodgdon H414 | <<locked>> | 82% | 55,593 psi | 87% | 3196 fps | 100% |
| Hodgdon H4831 | <<locked>> | 90% | 56,405 psi | 88% | 3205 fps | 98.8% |
| Hodgdon H4831 SC | <<locked>> | 90% | 55,347 psi | 87% | 3186 fps | 98.7% |
| Hodgdon Hybrid 100V | <<locked>> | 86% | 55,535 psi | 87% | 3117 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 98% | 57,276 psi | 90% | 3392 fps | 100% |
| Hodgdon Superformance | <<locked>> | 82% | 56,420 psi | 88% | 3238 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,260 psi | 58% | 2037 fps | 100% |
| IMR 4350 | <<locked>> | 84% | 54,302 psi | 85% | 3127 fps | 99.9% |
| IMR 4451 Enduron | <<locked>> | 82% | 57,116 psi | 90% | 3163 fps | 100% |
| IMR 4831 | <<locked>> | 84% | 54,476 psi | 85% | 3130 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 90% | 57,159 psi | 90% | 3186 fps | 99% |
| IMR 7828 SSC | <<locked>> | 92% | 54,897 psi | 86% | 3255 fps | 99.2% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 44,991 psi | 71% | 3091 fps | 97.8% |
| Lovex S065 | <<locked>> | 82% | 54,723 psi | 86% | 3107 fps | 100% |
| Lovex S070 | <<locked>> | 84% | 56,521 psi | 89% | 3159 fps | 100% |
| Lovex S071 | <<locked>> | 96% | 55,013 psi | 86% | 3133 fps | 100% |
| Norma 204 | <<locked>> | 84% | 55,477 psi | 87% | 3186 fps | 99.6% |
| Norma 217ᴾ | <<locked>> | 100% | 45,527 psi | 71% | 3120 fps | 99.5% |
| Norma MRP | <<locked>> | 90% | 57,319 psi | 90% | 3294 fps | 100% |
| Norma URP | <<locked>> | 84% | 56,217 psi | 88% | 3179 fps | 100% |
| Ramshot Grand | <<locked>> | 92% | 55,941 psi | 88% | 3278 fps | 99.5% |
| Ramshot Hunter | <<locked>> | 84% | 55,259 psi | 87% | 3186 fps | 100% |
| Ramshot Magnum | <<locked>> | 94% | 54,418 psi | 85% | 3202 fps | 99.9% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,232 psi | 60% | 2087 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 82% | 54,389 psi | 85% | 3163 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 84% | 56,739 psi | 89% | 3255 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 96% | 54,360 psi | 85% | 3320 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 98% | 53,621 psi | 84% | 3268 fps | 98.4% |
| Rottweil R 904 | <<locked>> | 88% | 56,101 psi | 88% | 3173 fps | 99.2% |
| Rottweil R 905 | <<locked>> | 88% | 54,404 psi | 85% | 3182 fps | 99.7% |
| Rottweil R 907 | <<locked>> | 82% | 55,956 psi | 88% | 3140 fps | 99.9% |
| Shooters World Long Rifle | <<locked>> | 82% | 54,723 psi | 86% | 3107 fps | 100% |
| Shooters World SW4350 | <<locked>> | 84% | 56,521 psi | 89% | 3159 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 84% | 57,392 psi | 90% | 3114 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 90% | 57,696 psi | 90% | 3241 fps | 99.9% |
| Somchem S361 | <<locked>> | 88% | 57,740 psi | 90% | 3163 fps | 99% |
| Somchem S365 | <<locked>> | 86% | 57,203 psi | 90% | 3182 fps | 100% |
| Somchem S385 | <<locked>> | 88% | 54,766 psi | 86% | 3153 fps | 99.9% |
| Vihtavuori N160 | <<locked>> | 82% | 54,114 psi | 85% | 3110 fps | 100% |
| Vihtavuori N165 | <<locked>> | 92% | 54,404 psi | 85% | 3130 fps | 99.8% |
| Vihtavuori N550 | <<locked>> | 84% | 57,072 psi | 89% | 3173 fps | 100% |
| Vihtavuori N555 | <<locked>> | 90% | 57,043 psi | 89% | 3209 fps | 100% |
| Vihtavuori N560 | <<locked>> | 90% | 56,869 psi | 89% | 3291 fps | 99.1% |
| Vihtavuori N565 | <<locked>> | 96% | 57,276 psi | 90% | 3274 fps | 99.3% |
| Vihtavuori N568 | <<locked>> | 98% | 54,331 psi | 85% | 3271 fps | 98% |
| Vihtavuori N570ᴾ | <<locked>> | 100% | 55,259 psi | 87% | 3330 fps | 96.5% |
| Winchester 6.5 StaBALL | <<locked>> | 84% | 57,435 psi | 90% | 3114 fps | 100% |
| Winchester 760 | <<locked>> | 82% | 55,854 psi | 88% | 3202 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 92% | 53,476 psi | 84% | 3264 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 90% | 54,665 psi | 86% | 3146 fps | 99.6% |
Recommended = one of the top powders for this cartridge and bullet combination.
Start Load - Barrel Length: 26"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 3100 | <<locked>> | 80% | 38,058 psi | 60% | 2808 fps | 98.7% |
| Accurate 4350 | <<locked>> | 80% | 50,575 psi | 79% | 3081 fps | 100% |
| Accurate High Country | 58.6 gr | 80% | 41,568 psi | 65% | 2995 fps | 96.4% |
| Accurate MAGPRO | <<locked>> | 82% | 42,192 psi | 66% | 2995 fps | 95.2% |
| ADI AR 2209 | <<locked>> | 80% | 42,032 psi | 66% | 2949 fps | 97.5% |
| ADI AR 2213 | <<locked>> | 82% | 40,364 psi | 63% | 2940 fps | 95.8% |
| ADI AR 2217 | <<locked>> | 90% | 39,218 psi | 61% | 2907 fps | 95.8% |
| ADI AR 2225 | <<locked>> | 86% | 31,096 psi | 49% | 2730 fps | 95.5% |
| Alliant Power Pro Varmint | <<locked>> | 80% | 42,438 psi | 67% | 2949 fps | 97.6% |
| Alliant Reloder-16 | <<locked>> | 80% | 48,443 psi | 76% | 3087 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 42,061 psi | 66% | 2943 fps | 97.6% |
| Alliant Reloder-22 | <<locked>> | 80% | 37,942 psi | 59% | 2881 fps | 96.5% |
| Alliant Reloder-23 | <<locked>> | 80% | 36,709 psi | 58% | 2835 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 31,734 psi | 50% | 2746 fps | 97.6% |
| Alliant Reloder-26 | <<locked>> | 80% | 40,828 psi | 64% | 2999 fps | 99.9% |
| Alliant Reloder-33 | <<locked>> | 98% | 48,428 psi | 76% | 3176 fps | 95.1% |
| Baschieri & Pellagri 109 | <<locked>> | 88% | 48,080 psi | 75% | 3038 fps | 95.1% |
| Bofors RP15 | <<locked>> | 80% | 35,346 psi | 55% | 2808 fps | 95.3% |
| Bofors RP30 | <<locked>> | 88% | 38,551 psi | 60% | 2920 fps | 95.9% |
| Bofors RP5 | <<locked>> | 80% | 37,942 psi | 59% | 2881 fps | 96.5% |
| Bofors RP7 | <<locked>> | 80% | 52,475 psi | 82% | 3081 fps | 99.8% |
| Hodgdon H1000 | <<locked>> | 86% | 37,275 psi | 58% | 2861 fps | 95.7% |
| Hodgdon H414 | <<locked>> | 80% | 52,112 psi | 82% | 3136 fps | 99.9% |
| Hodgdon H4831 | <<locked>> | 80% | 40,103 psi | 63% | 2881 fps | 95% |
| Hodgdon H4831 SC | <<locked>> | 82% | 42,308 psi | 66% | 2930 fps | 95.8% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 45,571 psi | 71% | 2953 fps | 100% |
| Hodgdon Retumbo | 57.8 gr | 82% | 33,098 psi | 52% | 2831 fps | 95% |
| Hodgdon Superformance | <<locked>> | 80% | 52,301 psi | 82% | 3169 fps | 99.9% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,963 psi | 44% | 1824 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 47,776 psi | 75% | 3005 fps | 99.4% |
| IMR 4451 Enduron | <<locked>> | 80% | 53,882 psi | 84% | 3107 fps | 99.9% |
| IMR 4831 | <<locked>> | 80% | 48,022 psi | 75% | 3022 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 41,568 psi | 65% | 2877 fps | 95.7% |
| IMR 7828 SSC | <<locked>> | 82% | 38,914 psi | 61% | 2913 fps | 95.3% |
| IMR 8133 Enduron | <<locked>> | 96% | 39,291 psi | 62% | 2956 fps | 96% |
| Lovex S065 | <<locked>> | 80% | 51,372 psi | 81% | 3051 fps | 100% |
| Lovex S070 | <<locked>> | 80% | 49,748 psi | 78% | 3045 fps | 99.8% |
| Lovex S071 | <<locked>> | 80% | 32,851 psi | 51% | 2674 fps | 97.2% |
| Norma 204 | <<locked>> | 80% | 48,356 psi | 76% | 3058 fps | 98.7% |
| Norma 217 | <<locked>> | 90% | 32,213 psi | 50% | 2789 fps | 95.4% |
| Norma MRP | <<locked>> | 80% | 40,147 psi | 63% | 2959 fps | 98.4% |
| Norma URP | <<locked>> | 80% | 49,255 psi | 77% | 3061 fps | 100% |
| Ramshot Grand | <<locked>> | 82% | 38,580 psi | 60% | 2920 fps | 95.7% |
| Ramshot Hunter | <<locked>> | 80% | 48,312 psi | 76% | 3064 fps | 99.9% |
| Ramshot Magnum | <<locked>> | 80% | 32,097 psi | 50% | 2720 fps | 95% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,703 psi | 45% | 1870 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 50,676 psi | 79% | 3104 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 48,994 psi | 77% | 3127 fps | 100% |
| ReloadSwiss RS 76 | 61.9 gr | 82% | 32,358 psi | 51% | 2802 fps | 96% |
| ReloadSwiss RS 80 | <<locked>> | 92% | 42,467 psi | 67% | 3041 fps | 95.6% |
| Rottweil R 904 | <<locked>> | 80% | 43,163 psi | 68% | 2923 fps | 96.8% |
| Rottweil R 905 | <<locked>> | 80% | 41,524 psi | 65% | 2930 fps | 97.6% |
| Rottweil R 907 | <<locked>> | 80% | 52,475 psi | 82% | 3081 fps | 99.8% |
| Shooters World Long Rifle | <<locked>> | 80% | 51,372 psi | 81% | 3051 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 49,748 psi | 78% | 3045 fps | 99.8% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 50,212 psi | 79% | 2995 fps | 99.8% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 41,191 psi | 65% | 2923 fps | 97.5% |
| Somchem S361 | <<locked>> | 80% | 44,135 psi | 69% | 2910 fps | 96.3% |
| Somchem S365 | <<locked>> | 80% | 46,615 psi | 73% | 3012 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 42,003 psi | 66% | 2907 fps | 98.4% |
| Vihtavuori N160 | <<locked>> | 80% | 50,676 psi | 79% | 3054 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 36,521 psi | 57% | 2769 fps | 96.6% |
| Vihtavuori N550 | <<locked>> | 80% | 49,995 psi | 78% | 3058 fps | 100% |
| Vihtavuori N555 | <<locked>> | 80% | 41,017 psi | 64% | 2920 fps | 100% |
| Vihtavuori N560 | <<locked>> | 80% | 40,103 psi | 63% | 2949 fps | 95.2% |
| Vihtavuori N565 | <<locked>> | 86% | 40,683 psi | 64% | 2943 fps | 95.7% |
| Vihtavuori N568 | <<locked>> | 92% | 43,743 psi | 69% | 3058 fps | 95.3% |
| Vihtavuori N570 | <<locked>> | 98% | 51,285 psi | 80% | 3255 fps | 95.5% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 50,053 psi | 78% | 3005 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 52,112 psi | 82% | 3136 fps | 99.9% |
| Winchester StaBALL HD | <<locked>> | 80% | 33,547 psi | 53% | 2874 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 38,551 psi | 60% | 2828 fps | 96.6% |
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 72 powders for .257 Weath. Mag. loaded with the .257 | 115gr | Berger VLD Target. Hodgdon Retumbo delivers the highest muzzle velocity at 3,392 fps; across all powders the maximum-charge window runs from 2,037 fps to 3,392 fps. ADI AR 2217 gives the best case fill at 100 %, and 72 of the 72 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 115.0 gr projectile in 0.257" calls for a 1:9.5 twist; slower twists will usually not stabilise this weight. ADI AR 2217, ADI AR 2225, Alliant Reloder-33 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. Hodgdon Retumbo, ReloadSwiss RS 76, Accurate High Country rank at the top here: for .257 Weath. Mag. with the .257 | 115gr | Berger VLD Target 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.