Load Specifications
Load data in caliber .257 Weath. Mag. with .257 | 105gr | Reichenberg Spezial Jagd bullet and 70 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 Vihtavuori N560.
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% | 55,405 psi | 87% | 3261 fps | 100% |
| Accurate 4350 | <<locked>> | 84% | 56,159 psi | 88% | 3301 fps | 100% |
| Accurate MAGPRO | <<locked>> | 92% | 54,984 psi | 86% | 3366 fps | 97.1% |
| ADI AR 2209 | <<locked>> | 90% | 57,145 psi | 90% | 3363 fps | 99.5% |
| ADI AR 2213 | <<locked>> | 92% | 54,998 psi | 86% | 3366 fps | 98.6% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 53,229 psi | 83% | 3320 fps | 98.7% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 47,630 psi | 75% | 3271 fps | 99.8% |
| Alliant Reloder-16 | <<locked>> | 86% | 57,000 psi | 89% | 3363 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 90% | 56,550 psi | 89% | 3346 fps | 99.5% |
| Alliant Reloder-22 | <<locked>> | 92% | 55,274 psi | 87% | 3360 fps | 99.4% |
| Alliant Reloder-23 | <<locked>> | 94% | 56,550 psi | 89% | 3330 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 98% | 56,246 psi | 88% | 3396 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 90% | 57,450 psi | 90% | 3428 fps | 100% |
| Baschieri & Pellagri 109 | <<locked>> | 94% | 56,492 psi | 89% | 3314 fps | 96.4% |
| Bofors RP15 | <<locked>> | 94% | 54,476 psi | 85% | 3346 fps | 99.3% |
| Bofors RP30ᴾ | <<locked>> | 100% | 56,014 psi | 88% | 3396 fps | 99.2% |
| Bofors RP5 | <<locked>> | 92% | 55,274 psi | 87% | 3360 fps | 99.4% |
| Bofors RP7 | <<locked>> | 82% | 54,259 psi | 85% | 3238 fps | 99.6% |
| Hodgdon H1000ᴾ | <<locked>> | 100% | 54,737 psi | 86% | 3350 fps | 99.3% |
| Hodgdon H4350 | <<locked>> | 84% | 54,897 psi | 86% | 3284 fps | 99.4% |
| Hodgdon H4831 | <<locked>> | 94% | 54,346 psi | 85% | 3287 fps | 97.9% |
| Hodgdon H4831 SC | <<locked>> | 92% | 57,450 psi | 90% | 3343 fps | 98.4% |
| Hodgdon Hybrid 100V | <<locked>> | 88% | 57,305 psi | 90% | 3274 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 98% | 55,187 psi | 86% | 3481 fps | 99.9% |
| Hodgdon Superformance | <<locked>> | 82% | 54,534 psi | 85% | 3330 fps | 99.8% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,231 psi | 58% | 2136 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 82% | 57,101 psi | 89% | 3268 fps | 99.9% |
| IMR 4350 | <<locked>> | 86% | 56,260 psi | 88% | 3284 fps | 99.8% |
| IMR 4451 Enduron | <<locked>> | 82% | 55,637 psi | 87% | 3261 fps | 99.9% |
| IMR 4831 | <<locked>> | 90% | 57,667 psi | 90% | 3307 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 90% | 55,651 psi | 87% | 3281 fps | 98.3% |
| IMR 7828 SSC | <<locked>> | 92% | 57,087 psi | 89% | 3412 fps | 99% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 43,221 psi | 68% | 3159 fps | 96.4% |
| Lovex S065 | <<locked>> | 84% | 56,420 psi | 88% | 3261 fps | 100% |
| Lovex S070 | <<locked>> | 84% | 54,824 psi | 86% | 3258 fps | 99.9% |
| Lovex S071 | <<locked>> | 98% | 56,478 psi | 89% | 3278 fps | 100% |
| Norma 204 | <<locked>> | 86% | 57,319 psi | 90% | 3343 fps | 99.4% |
| Norma 217ᴾ | <<locked>> | 100% | 43,366 psi | 68% | 3186 fps | 98.6% |
| Norma MRP | <<locked>> | 90% | 55,042 psi | 86% | 3379 fps | 99.9% |
| Norma URP | <<locked>> | 84% | 54,375 psi | 85% | 3278 fps | 100% |
| Ramshot Grand | <<locked>> | 90% | 57,130 psi | 90% | 3419 fps | 99.2% |
| Ramshot Hunter | <<locked>> | 86% | 56,942 psi | 89% | 3343 fps | 100% |
| Ramshot Magnum | <<locked>> | 92% | 54,244 psi | 85% | 3317 fps | 99.7% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,942 psi | 59% | 2182 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 84% | 56,333 psi | 88% | 3323 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 84% | 54,520 psi | 85% | 3350 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 98% | 56,260 psi | 88% | 3474 fps | 100% |
| ReloadSwiss RS 80ᴾ | <<locked>> | 100% | 55,622 psi | 87% | 3415 fps | 98.1% |
| Rottweil R 904 | <<locked>> | 88% | 54,433 psi | 85% | 3268 fps | 98.5% |
| Rottweil R 905 | <<locked>> | 90% | 56,086 psi | 88% | 3333 fps | 99.5% |
| Rottweil R 907 | <<locked>> | 82% | 54,259 psi | 85% | 3238 fps | 99.6% |
| Shooters World Long Rifle | <<locked>> | 84% | 56,420 psi | 88% | 3261 fps | 100% |
| Shooters World SW4350 | <<locked>> | 84% | 54,824 psi | 86% | 3258 fps | 99.9% |
| SNPE Vectan Tubal 7000 | <<locked>> | 84% | 55,695 psi | 87% | 3209 fps | 99.9% |
| SNPE Vectan Tubal 8000 | <<locked>> | 90% | 55,651 psi | 87% | 3330 fps | 99.4% |
| Somchem S361 | <<locked>> | 88% | 55,912 psi | 88% | 3251 fps | 98.2% |
| Somchem S365 | <<locked>> | 86% | 55,245 psi | 87% | 3281 fps | 100% |
| Somchem S385 | <<locked>> | 90% | 56,579 psi | 89% | 3304 fps | 99.8% |
| Unknown powder | <<locked>> | 82% | 54,389 psi | 85% | 3281 fps | 100% |
| Vihtavuori N150 | <<locked>> | 86% | 57,363 psi | 90% | 3215 fps | 100% |
| Vihtavuori N160 | <<locked>> | 82% | 54,592 psi | 86% | 3241 fps | 100% |
| Vihtavuori N165 | <<locked>> | 94% | 54,549 psi | 85% | 3251 fps | 99.6% |
| Vihtavuori N550 | <<locked>> | 82% | 55,303 psi | 87% | 3294 fps | 100% |
| Vihtavuori N555 | <<locked>> | 90% | 54,984 psi | 86% | 3304 fps | 100% |
| Vihtavuori N560 | <<locked>> | 92% | 55,535 psi | 87% | 3389 fps | 98.3% |
| Vihtavuori N565 | <<locked>> | 96% | 55,085 psi | 86% | 3353 fps | 98.5% |
| Vihtavuori N568ᴾ | <<locked>> | 100% | 56,246 psi | 88% | 3419 fps | 97.7% |
| Winchester 6.5 StaBALL | <<locked>> | 84% | 55,724 psi | 87% | 3215 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 94% | 55,187 psi | 86% | 3419 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 88% | 54,085 psi | 85% | 3255 fps | 99.2% |
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% | 36,695 psi | 57% | 2884 fps | 97.7% |
| Accurate 4350 | <<locked>> | 80% | 48,921 psi | 77% | 3173 fps | 100% |
| Accurate MAGPRO | <<locked>> | 88% | 47,601 psi | 75% | 3219 fps | 95.2% |
| ADI AR 2209 | <<locked>> | 80% | 40,683 psi | 64% | 3028 fps | 96.3% |
| ADI AR 2213 | <<locked>> | 84% | 41,597 psi | 65% | 3081 fps | 95.2% |
| ADI AR 2217 | <<locked>> | 92% | 40,335 psi | 63% | 3035 fps | 95.1% |
| ADI AR 2225 | <<locked>> | 90% | 34,171 psi | 54% | 2923 fps | 96% |
| Alliant Reloder-16 | <<locked>> | 80% | 46,702 psi | 73% | 3179 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 40,727 psi | 64% | 3022 fps | 96.4% |
| Alliant Reloder-22 | <<locked>> | 82% | 39,247 psi | 62% | 3022 fps | 96% |
| Alliant Reloder-23 | <<locked>> | 80% | 35,172 psi | 55% | 2910 fps | 99.7% |
| Alliant Reloder-25 | <<locked>> | 80% | 30,618 psi | 48% | 2805 fps | 96% |
| Alliant Reloder-26 | <<locked>> | 80% | 39,073 psi | 61% | 3071 fps | 99.4% |
| Baschieri & Pellagri 109 | <<locked>> | 92% | 53,098 psi | 83% | 3248 fps | 95.6% |
| Bofors RP15 | <<locked>> | 84% | 38,943 psi | 61% | 3012 fps | 95.7% |
| Bofors RP30 | <<locked>> | 90% | 39,639 psi | 62% | 3054 fps | 95.3% |
| Bofors RP5 | <<locked>> | 82% | 39,247 psi | 62% | 3022 fps | 96% |
| Bofors RP7 | <<locked>> | 80% | 50,966 psi | 80% | 3176 fps | 99.3% |
| Hodgdon H1000 | <<locked>> | 90% | 38,769 psi | 61% | 3002 fps | 95.3% |
| Hodgdon H4350 | <<locked>> | 80% | 48,399 psi | 76% | 3159 fps | 98.5% |
| Hodgdon H4831 | <<locked>> | 88% | 44,657 psi | 70% | 3091 fps | 95.6% |
| Hodgdon H4831 SC | <<locked>> | 84% | 43,598 psi | 68% | 3068 fps | 95.2% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 44,005 psi | 69% | 3045 fps | 100% |
| Hodgdon Retumbo | 62.6 gr | 86% | 36,593 psi | 57% | 3038 fps | 95.6% |
| Hodgdon Superformance | <<locked>> | 80% | 50,604 psi | 79% | 3258 fps | 99.5% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,847 psi | 44% | 1913 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 80% | 53,650 psi | 84% | 3205 fps | 99.8% |
| IMR 4350 | <<locked>> | 80% | 46,456 psi | 73% | 3097 fps | 98.7% |
| IMR 4451 Enduron | <<locked>> | 80% | 52,315 psi | 82% | 3202 fps | 99.6% |
| IMR 4831 | <<locked>> | 80% | 42,003 psi | 66% | 3018 fps | 99.8% |
| IMR 4955 Enduron | <<locked>> | 82% | 43,047 psi | 67% | 3022 fps | 95.3% |
| IMR 7828 SSC | <<locked>> | 84% | 42,844 psi | 67% | 3120 fps | 95.8% |
| IMR 8133 Enduron | <<locked>> | 98% | 40,379 psi | 63% | 3091 fps | 95.4% |
| Lovex S065 | <<locked>> | 80% | 49,864 psi | 78% | 3146 fps | 99.9% |
| Lovex S070 | <<locked>> | 80% | 48,211 psi | 76% | 3133 fps | 99.4% |
| Lovex S071 | <<locked>> | 80% | 31,488 psi | 49% | 2740 fps | 95.7% |
| Norma 204 | <<locked>> | 80% | 46,818 psi | 73% | 3143 fps | 97.8% |
| Norma 217 | <<locked>> | 94% | 35,331 psi | 55% | 2979 fps | 95.9% |
| Norma MRP | <<locked>> | 80% | 38,464 psi | 60% | 3028 fps | 97.2% |
| Norma URP | <<locked>> | 80% | 47,558 psi | 75% | 3153 fps | 100% |
| Ramshot Grand | <<locked>> | 82% | 41,771 psi | 65% | 3107 fps | 95.9% |
| Ramshot Hunter | <<locked>> | 80% | 46,688 psi | 73% | 3153 fps | 99.5% |
| Ramshot Magnum | <<locked>> | 82% | 36,593 psi | 57% | 2946 fps | 96.1% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,529 psi | 45% | 1962 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 48,834 psi | 77% | 3192 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 47,021 psi | 74% | 3212 fps | 100% |
| ReloadSwiss RS 76 | 65.4 gr | 84% | 33,446 psi | 52% | 2930 fps | 95.4% |
| ReloadSwiss RS 80 | <<locked>> | 94% | 44,005 psi | 69% | 3182 fps | 95.1% |
| Rottweil R 904 | <<locked>> | 80% | 41,945 psi | 66% | 3005 fps | 95.5% |
| Rottweil R 905 | <<locked>> | 80% | 39,958 psi | 63% | 3002 fps | 96.3% |
| Rottweil R 907 | <<locked>> | 80% | 50,966 psi | 80% | 3176 fps | 99.3% |
| Shooters World Long Rifle | <<locked>> | 80% | 49,864 psi | 78% | 3146 fps | 99.9% |
| Shooters World SW4350 | <<locked>> | 80% | 48,211 psi | 76% | 3133 fps | 99.4% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 48,907 psi | 77% | 3087 fps | 99.4% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 39,624 psi | 62% | 2995 fps | 96.1% |
| Somchem S361 | <<locked>> | 80% | 42,656 psi | 67% | 2986 fps | 95% |
| Somchem S365 | <<locked>> | 80% | 44,991 psi | 71% | 3107 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 40,611 psi | 64% | 2986 fps | 97.4% |
| Unknown powder | <<locked>> | 80% | 50,995 psi | 80% | 3219 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 47,616 psi | 75% | 3058 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 51,242 psi | 80% | 3182 fps | 100% |
| Vihtavuori N165 | <<locked>> | 82% | 36,622 psi | 57% | 2877 fps | 95.7% |
| Vihtavuori N550 | <<locked>> | 80% | 51,750 psi | 81% | 3232 fps | 100% |
| Vihtavuori N555 | <<locked>> | 80% | 39,378 psi | 62% | 2999 fps | 99.7% |
| Vihtavuori N560 | 63.6 gr | 86% | 45,223 psi | 71% | 3179 fps | 95.9% |
| Vihtavuori N565 | <<locked>> | 88% | 41,843 psi | 66% | 3077 fps | 95.2% |
| Vihtavuori N568 | <<locked>> | 96% | 48,428 psi | 76% | 3268 fps | 95.9% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 48,486 psi | 76% | 3100 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 80% | 31,662 psi | 50% | 2936 fps | 99.9% |
| Winchester Supreme 780 | <<locked>> | 80% | 40,553 psi | 64% | 2979 fps | 96.4% |
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 75 powders for .257 Weath. Mag. loaded with the .257 | 105gr | Reichenberg Spezial Jagd. Hodgdon Retumbo delivers the highest muzzle velocity at 3,481 fps; across all powders the maximum-charge window runs from 2,136 fps to 3,481 fps. ADI AR 2217 gives the best case fill at 100 %, and 75 of the 75 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 105.0 gr projectile in 0.257" calls for a 1:11.5 twist; slower twists will usually not stabilise this weight. ADI AR 2217, ADI AR 2218, ADI AR 2225 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, Vihtavuori N560 rank at the top here: for .257 Weath. Mag. with the .257 | 105gr | Reichenberg Spezial Jagd they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, ADI AR 2218, Alliant Reloder-33, IMR 7977 Enduron 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.