Load Specifications
Load data in caliber .257 Weath. Mag. with .257 | 110gr | Nosler AccuBond bullet and 72 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are IMR 4350, Hodgdon Retumbo and ReloadSwiss RS 76.
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% | 56,420 psi | 88% | 3215 fps | 100% |
| Accurate 4350 | <<locked>> | 84% | 57,174 psi | 90% | 3251 fps | 100% |
| Accurate High Country | <<locked>> | 88% | 54,230 psi | 85% | 3317 fps | 98.9% |
| Accurate MAGPRO | <<locked>> | 90% | 55,100 psi | 86% | 3320 fps | 98.1% |
| ADI AR 2209 | <<locked>> | 88% | 54,302 psi | 85% | 3251 fps | 99.4% |
| ADI AR 2213 | <<locked>> | 92% | 55,999 psi | 88% | 3320 fps | 99% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 54,114 psi | 85% | 3278 fps | 99.1% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 48,762 psi | 76% | 3235 fps | 100% |
| Alliant Power Pro Varmint | <<locked>> | 88% | 54,476 psi | 85% | 3248 fps | 99.4% |
| Alliant Reloder-16 | <<locked>> | 84% | 54,302 psi | 85% | 3251 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 90% | 57,392 psi | 90% | 3301 fps | 99.7% |
| Alliant Reloder-22 | <<locked>> | 92% | 56,304 psi | 88% | 3317 fps | 99.7% |
| Alliant Reloder-23 | <<locked>> | 94% | 57,609 psi | 90% | 3281 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 98% | 57,566 psi | 90% | 3353 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 88% | 54,346 psi | 85% | 3314 fps | 100% |
| Baschieri & Pellagri 109 | <<locked>> | 94% | 57,188 psi | 90% | 3268 fps | 96.9% |
| Bofors RP15 | <<locked>> | 94% | 55,477 psi | 87% | 3301 fps | 99.6% |
| Bofors RP30ᴾ | <<locked>> | 100% | 57,363 psi | 90% | 3356 fps | 99.5% |
| Bofors RP5 | <<locked>> | 92% | 56,304 psi | 88% | 3317 fps | 99.7% |
| Bofors RP7 | <<locked>> | 82% | 55,216 psi | 87% | 3192 fps | 99.8% |
| Hodgdon H1000 | <<locked>> | 98% | 55,680 psi | 87% | 3307 fps | 99.6% |
| Hodgdon H414 | <<locked>> | 82% | 54,940 psi | 86% | 3248 fps | 100% |
| Hodgdon H4350 | <<locked>> | 82% | 57,203 psi | 90% | 3261 fps | 99.7% |
| Hodgdon H4831 | <<locked>> | 90% | 55,738 psi | 87% | 3251 fps | 98.4% |
| Hodgdon H4831 SC | <<locked>> | 90% | 54,433 psi | 85% | 3228 fps | 98.2% |
| Hodgdon Hybrid 100V | <<locked>> | 86% | 54,607 psi | 86% | 3169 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 98% | 56,202 psi | 88% | 3435 fps | 100% |
| Hodgdon Superformance | <<locked>> | 82% | 55,492 psi | 87% | 3284 fps | 99.9% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,231 psi | 58% | 2083 fps | 100% |
| IMR 4350 | <<locked>> | 86% | 57,159 psi | 90% | 3235 fps | 99.9% |
| IMR 4451 Enduron | <<locked>> | 82% | 56,376 psi | 88% | 3212 fps | 100% |
| IMR 4831 | <<locked>> | 86% | 57,392 psi | 90% | 3238 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 90% | 56,376 psi | 88% | 3228 fps | 98.7% |
| IMR 7828 SSC | <<locked>> | 92% | 54,172 psi | 85% | 3297 fps | 98.8% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 44,106 psi | 69% | 3123 fps | 97.1% |
| Lovex S065 | <<locked>> | 84% | 57,464 psi | 90% | 3212 fps | 100% |
| Lovex S070 | <<locked>> | 84% | 55,666 psi | 87% | 3209 fps | 100% |
| Lovex S071 | <<locked>> | 98% | 57,740 psi | 90% | 3235 fps | 100% |
| Norma 204 | <<locked>> | 84% | 54,476 psi | 85% | 3228 fps | 99.3% |
| Norma 217ᴾ | <<locked>> | 100% | 44,556 psi | 70% | 3153 fps | 99.1% |
| Norma MRP | <<locked>> | 90% | 56,159 psi | 88% | 3337 fps | 100% |
| Norma URP | <<locked>> | 84% | 55,274 psi | 87% | 3228 fps | 100% |
| Ramshot Grand | <<locked>> | 92% | 54,984 psi | 86% | 3320 fps | 99.2% |
| Ramshot Hunter | <<locked>> | 84% | 54,244 psi | 85% | 3232 fps | 100% |
| Ramshot Magnum | <<locked>> | 96% | 57,638 psi | 90% | 3310 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,159 psi | 60% | 2136 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 84% | 57,188 psi | 90% | 3271 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 84% | 55,767 psi | 87% | 3301 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 98% | 57,595 psi | 90% | 3432 fps | 100% |
| ReloadSwiss RS 80ᴾ | <<locked>> | 100% | 56,739 psi | 89% | 3376 fps | 98.6% |
| Rottweil R 904 | <<locked>> | 88% | 55,143 psi | 86% | 3215 fps | 98.8% |
| Rottweil R 905 | <<locked>> | 90% | 57,217 psi | 90% | 3291 fps | 99.7% |
| Rottweil R 907 | <<locked>> | 82% | 55,216 psi | 87% | 3192 fps | 99.8% |
| Shooters World Long Rifle | <<locked>> | 84% | 57,464 psi | 90% | 3212 fps | 100% |
| Shooters World SW4350 | <<locked>> | 84% | 55,666 psi | 87% | 3209 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 84% | 56,550 psi | 89% | 3159 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 90% | 56,782 psi | 89% | 3287 fps | 99.7% |
| Somchem S361 | <<locked>> | 88% | 56,797 psi | 89% | 3205 fps | 98.6% |
| Somchem S365 | <<locked>> | 86% | 56,333 psi | 88% | 3235 fps | 100% |
| Somchem S385 | <<locked>> | 90% | 57,508 psi | 90% | 3255 fps | 99.9% |
| Vihtavuori N150 | <<locked>> | 82% | 57,406 psi | 90% | 3146 fps | 100% |
| Vihtavuori N160 | <<locked>> | 84% | 57,072 psi | 89% | 3222 fps | 100% |
| Vihtavuori N165 | <<locked>> | 94% | 57,348 psi | 90% | 3235 fps | 99.9% |
| Vihtavuori N550 | <<locked>> | 84% | 56,347 psi | 88% | 3225 fps | 100% |
| Vihtavuori N555 | <<locked>> | 90% | 56,115 psi | 88% | 3255 fps | 100% |
| Vihtavuori N560 | <<locked>> | 90% | 55,811 psi | 87% | 3333 fps | 98.7% |
| Vihtavuori N565 | <<locked>> | 96% | 56,289 psi | 88% | 3314 fps | 98.9% |
| Vihtavuori N568ᴾ | <<locked>> | 100% | 57,522 psi | 90% | 3383 fps | 98.3% |
| Winchester 6.5 StaBALL | <<locked>> | 84% | 56,565 psi | 89% | 3163 fps | 100% |
| Winchester 760 | <<locked>> | 82% | 54,940 psi | 86% | 3248 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 94% | 56,710 psi | 89% | 3376 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 92% | 57,740 psi | 90% | 3255 fps | 99.7% |
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% | 37,376 psi | 59% | 2844 fps | 98.2% |
| Accurate 4350 | <<locked>> | 80% | 49,748 psi | 78% | 3127 fps | 100% |
| Accurate High Country | <<locked>> | 80% | 40,712 psi | 64% | 3028 fps | 95.6% |
| Accurate MAGPRO | <<locked>> | 84% | 44,338 psi | 69% | 3100 fps | 95.4% |
| ADI AR 2209 | <<locked>> | 80% | 41,336 psi | 65% | 2989 fps | 97% |
| ADI AR 2213 | <<locked>> | 82% | 39,653 psi | 62% | 2976 fps | 95% |
| ADI AR 2217 | <<locked>> | 90% | 38,566 psi | 60% | 2940 fps | 95% |
| ADI AR 2225 | <<locked>> | 88% | 32,648 psi | 51% | 2828 fps | 95.8% |
| Alliant Power Pro Varmint | <<locked>> | 80% | 41,771 psi | 65% | 2989 fps | 97.1% |
| Alliant Reloder-16 | <<locked>> | 80% | 47,456 psi | 74% | 3130 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 41,394 psi | 65% | 2982 fps | 97% |
| Alliant Reloder-22 | <<locked>> | 80% | 37,231 psi | 58% | 2913 fps | 95.7% |
| Alliant Reloder-23 | <<locked>> | 80% | 36,013 psi | 56% | 2877 fps | 99.9% |
| Alliant Reloder-25 | <<locked>> | 80% | 31,169 psi | 49% | 2772 fps | 96.9% |
| Alliant Reloder-26 | <<locked>> | 80% | 40,074 psi | 63% | 3038 fps | 99.7% |
| Baschieri & Pellagri 109 | <<locked>> | 90% | 50,488 psi | 79% | 3143 fps | 95.3% |
| Bofors RP15 | <<locked>> | 82% | 37,144 psi | 58% | 2910 fps | 95.5% |
| Bofors RP30 | <<locked>> | 88% | 37,768 psi | 59% | 2949 fps | 95.1% |
| Bofors RP5 | <<locked>> | 80% | 37,231 psi | 58% | 2913 fps | 95.7% |
| Bofors RP7 | <<locked>> | 80% | 51,851 psi | 81% | 3130 fps | 99.6% |
| Hodgdon H1000 | <<locked>> | 88% | 39,218 psi | 61% | 2963 fps | 96% |
| Hodgdon H414 | <<locked>> | 80% | 51,242 psi | 80% | 3182 fps | 99.8% |
| Hodgdon H4350 | <<locked>> | 80% | 53,476 psi | 84% | 3196 fps | 99.4% |
| Hodgdon H4831 | <<locked>> | 82% | 42,351 psi | 66% | 2982 fps | 95.3% |
| Hodgdon H4831 SC | <<locked>> | 82% | 41,553 psi | 65% | 2966 fps | 95% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 44,904 psi | 70% | 2999 fps | 100% |
| Hodgdon Retumbo | 60.2 gr | 84% | 34,853 psi | 55% | 2933 fps | 95.3% |
| Hodgdon Superformance | <<locked>> | 80% | 51,459 psi | 81% | 3212 fps | 99.7% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,891 psi | 44% | 1867 fps | 100% |
| IMR 4350 | 56.7 gr | 80% | 47,123 psi | 74% | 3051 fps | 99.1% |
| IMR 4451 Enduron | <<locked>> | 80% | 52,982 psi | 83% | 3153 fps | 99.8% |
| IMR 4831 | <<locked>> | 80% | 47,050 psi | 74% | 3061 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 40,988 psi | 64% | 2920 fps | 95.1% |
| IMR 7828 SSC | <<locked>> | 84% | 40,843 psi | 64% | 3018 fps | 95.6% |
| IMR 8133 Enduron | <<locked>> | 96% | 38,421 psi | 60% | 2986 fps | 95.1% |
| Lovex S065 | <<locked>> | 80% | 50,705 psi | 79% | 3100 fps | 100% |
| Lovex S070 | <<locked>> | 80% | 49,066 psi | 77% | 3091 fps | 99.6% |
| Lovex S071 | <<locked>> | 80% | 32,155 psi | 50% | 2707 fps | 96.5% |
| Norma 204 | <<locked>> | 80% | 47,572 psi | 75% | 3097 fps | 98.3% |
| Norma 217 | <<locked>> | 92% | 33,765 psi | 53% | 2884 fps | 95.7% |
| Norma MRP | <<locked>> | 80% | 39,291 psi | 62% | 2992 fps | 97.8% |
| Norma URP | <<locked>> | 80% | 48,544 psi | 76% | 3110 fps | 100% |
| Ramshot Grand | <<locked>> | 84% | 40,901 psi | 64% | 3031 fps | 96.1% |
| Ramshot Hunter | <<locked>> | 80% | 47,514 psi | 74% | 3107 fps | 99.8% |
| Ramshot Magnum | <<locked>> | 82% | 33,982 psi | 53% | 2822 fps | 95.4% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,616 psi | 45% | 1913 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 49,748 psi | 78% | 3146 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 48,008 psi | 75% | 3166 fps | 100% |
| ReloadSwiss RS 76 | 62.9 gr | 82% | 31,778 psi | 50% | 2828 fps | 95.1% |
| ReloadSwiss RS 80 | <<locked>> | 94% | 44,991 psi | 71% | 3153 fps | 96% |
| Rottweil R 904 | <<locked>> | 80% | 42,569 psi | 67% | 2966 fps | 96.2% |
| Rottweil R 905 | <<locked>> | 80% | 40,857 psi | 64% | 2969 fps | 97% |
| Rottweil R 907 | <<locked>> | 80% | 51,851 psi | 81% | 3130 fps | 99.6% |
| Shooters World Long Rifle | <<locked>> | 80% | 50,705 psi | 79% | 3100 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 49,066 psi | 77% | 3091 fps | 99.6% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 49,545 psi | 78% | 3038 fps | 99.6% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 40,524 psi | 64% | 2963 fps | 96.9% |
| Somchem S361 | <<locked>> | 80% | 43,366 psi | 68% | 2949 fps | 95.7% |
| Somchem S365 | <<locked>> | 80% | 45,818 psi | 72% | 3058 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 41,307 psi | 65% | 2946 fps | 97.9% |
| Vihtavuori N150 | <<locked>> | 80% | 53,838 psi | 84% | 3094 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 49,937 psi | 78% | 3100 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 35,882 psi | 56% | 2805 fps | 95.9% |
| Vihtavuori N550 | <<locked>> | 80% | 49,443 psi | 77% | 3107 fps | 100% |
| Vihtavuori N555 | <<locked>> | 80% | 40,292 psi | 63% | 2959 fps | 99.9% |
| Vihtavuori N560 | <<locked>> | 82% | 42,221 psi | 66% | 3051 fps | 95.4% |
| Vihtavuori N565 | <<locked>> | 86% | 39,943 psi | 63% | 2976 fps | 95% |
| Vihtavuori N568 | <<locked>> | 94% | 46,166 psi | 72% | 3166 fps | 95.7% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 49,385 psi | 77% | 3051 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 51,488 psi | 81% | 3186 fps | 99.8% |
| Winchester StaBALL HD | <<locked>> | 80% | 32,605 psi | 51% | 2904 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 37,869 psi | 59% | 2861 fps | 95.9% |
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 | 110gr | Nosler AccuBond. Hodgdon Retumbo delivers the highest muzzle velocity at 3,435 fps; across all powders the maximum-charge window runs from 2,083 fps to 3,435 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 110.0 gr projectile in 0.257" calls for a 1:10.0 twist; slower twists will usually not stabilise this weight. ADI AR 2217, ADI AR 2225, Bofors RP30 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. IMR 4350, Hodgdon Retumbo, ReloadSwiss RS 76 rank at the top here: for .257 Weath. Mag. with the .257 | 110gr | Nosler AccuBond 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.