Load Specifications
Bullet Manufacturer:Berger
Bullet Weight:115 gr
Bullet Diameter:0.257"
Bullet Length:<<locked>>
Caliber:.257 Weath. Mag. load data
Case Length (l3):2.549"
Cartridge Length (C.O.L.):<<locked>>
Case Capacity:84 Grains of Water
Primer Size:Large Rifle Magnum (LRM)
Barrel Length:26"
Max. allowed Pressure:63,817 psi
Recommended Twist Rate:1:9.5
Load data in caliber .257 Weath. Mag. with .257 | 115gr | Berger VLD Hunting bullet and 145 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 Winchester StaBALL HD.
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: 26"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 3100 | <<locked>> | 92% | 57,479 psi | 90% | 3173 fps | 100% |
| Accurate 3100 | <<locked>> | 92% | 57,566 psi | 90% | 3176 fps | 100% |
| Accurate 4350 | <<locked>> | 82% | 54,230 psi | 85% | 3140 fps | 100% |
| Accurate 4350 | <<locked>> | 82% | 54,607 psi | 86% | 3146 fps | 100% |
| Accurate High Country | <<locked>> | 88% | 55,317 psi | 87% | 3274 fps | 99.2% |
| Accurate High Country | <<locked>> | 88% | 55,434 psi | 87% | 3278 fps | 99.3% |
| Accurate MAGPRO | <<locked>> | 90% | 56,275 psi | 88% | 3278 fps | 98.6% |
| Accurate MAGPRO | <<locked>> | 90% | 56,362 psi | 88% | 3281 fps | 98.6% |
| ADI AR 2209 | <<locked>> | 88% | 55,158 psi | 86% | 3209 fps | 99.7% |
| ADI AR 2209 | <<locked>> | 88% | 55,521 psi | 87% | 3215 fps | 99.7% |
| ADI AR 2213 | <<locked>> | 92% | 57,101 psi | 89% | 3281 fps | 99.4% |
| ADI AR 2213 | <<locked>> | 92% | 57,203 psi | 90% | 3281 fps | 99.4% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 55,085 psi | 86% | 3235 fps | 99.4% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 55,448 psi | 87% | 3245 fps | 99.5% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 49,748 psi | 78% | 3199 fps | 100% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 50,038 psi | 78% | 3202 fps | 100% |
| Alliant Power Pro Varmint | <<locked>> | 88% | 55,564 psi | 87% | 3205 fps | 99.7% |
| Alliant Power Pro Varmint | <<locked>> | 88% | 55,550 psi | 87% | 3205 fps | 99.7% |
| Alliant Power Pro Varmint | <<locked>> | 88% | 55,680 psi | 87% | 3209 fps | 99.7% |
| Alliant Reloder-16 | <<locked>> | 84% | 55,317 psi | 87% | 3202 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 84% | 55,448 psi | 87% | 3205 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 88% | 54,926 psi | 86% | 3196 fps | 99.6% |
| Alliant Reloder-19 | <<locked>> | 88% | 55,042 psi | 86% | 3199 fps | 99.7% |
| Alliant Reloder-22 | <<locked>> | 92% | 57,392 psi | 90% | 3274 fps | 99.9% |
| Alliant Reloder-22 | <<locked>> | 92% | 57,479 psi | 90% | 3278 fps | 99.9% |
| Alliant Reloder-23 | <<locked>> | 92% | 55,172 psi | 86% | 3182 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 92% | 55,317 psi | 87% | 3182 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 96% | 54,752 psi | 86% | 3248 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 96% | 55,129 psi | 86% | 3255 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 88% | 55,593 psi | 87% | 3274 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 88% | 55,999 psi | 88% | 3278 fps | 100% |
| Alliant Reloder-33ᴾ | <<locked>> | 100% | 52,475 psi | 82% | 3255 fps | 96.2% |
| Alliant Reloder-33ᴾ | <<locked>> | 100% | 52,765 psi | 83% | 3261 fps | 96.3% |
| Baschieri & Pellagri 109 | <<locked>> | 92% | 54,621 psi | 86% | 3169 fps | 96.8% |
| Baschieri & Pellagri 109 | <<locked>> | 92% | 54,853 psi | 86% | 3176 fps | 96.9% |
| Bofors RP15 | <<locked>> | 94% | 56,565 psi | 89% | 3261 fps | 99.8% |
| Bofors RP15 | <<locked>> | 94% | 56,637 psi | 89% | 3261 fps | 99.8% |
| Bofors RP30 | <<locked>> | 98% | 54,636 psi | 86% | 3255 fps | 99.4% |
| Bofors RP30 | <<locked>> | 98% | 54,984 psi | 86% | 3258 fps | 99.5% |
| Bofors RP5 | <<locked>> | 92% | 57,392 psi | 90% | 3274 fps | 99.9% |
| Bofors RP5 | <<locked>> | 92% | 57,479 psi | 90% | 3278 fps | 99.9% |
| Bofors RP7 | <<locked>> | 82% | 56,043 psi | 88% | 3143 fps | 99.9% |
| Bofors RP7 | <<locked>> | 82% | 56,159 psi | 88% | 3146 fps | 100% |
| Hodgdon H1000 | <<locked>> | 98% | 56,956 psi | 89% | 3271 fps | 99.8% |
| Hodgdon H1000 | <<locked>> | 98% | 57,000 psi | 89% | 3271 fps | 99.8% |
| Hodgdon H414 | <<locked>> | 82% | 55,680 psi | 87% | 3199 fps | 100% |
| Hodgdon H414 | <<locked>> | 82% | 56,057 psi | 88% | 3205 fps | 100% |
| Hodgdon H4831 | <<locked>> | 90% | 56,695 psi | 89% | 3209 fps | 98.9% |
| Hodgdon H4831 | <<locked>> | 90% | 56,797 psi | 89% | 3212 fps | 98.9% |
| Hodgdon H4831 SC | <<locked>> | 90% | 55,637 psi | 87% | 3192 fps | 98.7% |
| Hodgdon H4831 SC | <<locked>> | 90% | 55,724 psi | 87% | 3192 fps | 98.7% |
| Hodgdon Hybrid 100V | <<locked>> | 86% | 55,637 psi | 87% | 3120 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 86% | 55,753 psi | 87% | 3120 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 98% | 57,638 psi | 90% | 3399 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 98% | 57,725 psi | 90% | 3399 fps | 100% |
| Hodgdon Superformance | <<locked>> | 82% | 56,492 psi | 89% | 3238 fps | 100% |
| Hodgdon Superformance | <<locked>> | 82% | 56,855 psi | 89% | 3245 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,376 psi | 59% | 2041 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,391 psi | 59% | 2041 fps | 100% |
| IMR 4350 | <<locked>> | 84% | 54,331 psi | 85% | 3127 fps | 99.9% |
| IMR 4350 | <<locked>> | 84% | 54,723 psi | 86% | 3133 fps | 99.9% |
| IMR 4451 Enduron | <<locked>> | 82% | 57,421 psi | 90% | 3166 fps | 100% |
| IMR 4451 Enduron | <<locked>> | 82% | 57,537 psi | 90% | 3169 fps | 100% |
| IMR 4831 | <<locked>> | 84% | 54,810 psi | 86% | 3133 fps | 100% |
| IMR 4831 | <<locked>> | 84% | 54,940 psi | 86% | 3136 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 90% | 57,217 psi | 90% | 3189 fps | 99% |
| IMR 4955 Enduron | <<locked>> | 90% | 57,537 psi | 90% | 3196 fps | 99.1% |
| IMR 7828 SSC | <<locked>> | 92% | 55,274 psi | 87% | 3258 fps | 99.2% |
| IMR 7828 SSC | <<locked>> | 92% | 55,332 psi | 87% | 3261 fps | 99.2% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 45,266 psi | 71% | 3094 fps | 97.8% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 45,339 psi | 71% | 3097 fps | 97.9% |
| Lovex S065 | <<locked>> | 82% | 54,766 psi | 86% | 3107 fps | 100% |
| Lovex S065 | <<locked>> | 82% | 54,897 psi | 86% | 3110 fps | 100% |
| Lovex S070 | <<locked>> | 84% | 56,579 psi | 89% | 3163 fps | 100% |
| Lovex S070 | <<locked>> | 84% | 56,710 psi | 89% | 3163 fps | 100% |
| Lovex S071 | <<locked>> | 96% | 55,042 psi | 86% | 3136 fps | 100% |
| Lovex S071 | <<locked>> | 96% | 55,390 psi | 87% | 3140 fps | 100% |
| Norma 204 | <<locked>> | 84% | 55,492 psi | 87% | 3189 fps | 99.6% |
| Norma 204 | <<locked>> | 84% | 55,637 psi | 87% | 3192 fps | 99.6% |
| Norma 217ᴾ | <<locked>> | 100% | 45,600 psi | 71% | 3120 fps | 99.5% |
| Norma 217ᴾ | <<locked>> | 100% | 45,919 psi | 72% | 3127 fps | 99.5% |
| Norma MRP | <<locked>> | 90% | 57,348 psi | 90% | 3294 fps | 100% |
| Norma MRP | <<locked>> | 90% | 57,740 psi | 90% | 3301 fps | 100% |
| Norma URP | <<locked>> | 84% | 56,260 psi | 88% | 3182 fps | 100% |
| Norma URP | <<locked>> | 84% | 56,405 psi | 88% | 3182 fps | 100% |
| Ramshot Grand | <<locked>> | 92% | 55,999 psi | 88% | 3278 fps | 99.5% |
| Ramshot Grand | <<locked>> | 92% | 56,434 psi | 88% | 3284 fps | 99.6% |
| Ramshot Hunter | <<locked>> | 84% | 55,332 psi | 87% | 3186 fps | 100% |
| Ramshot Hunter | <<locked>> | 84% | 55,419 psi | 87% | 3192 fps | 100% |
| Ramshot Magnum | <<locked>> | 94% | 54,491 psi | 85% | 3202 fps | 99.9% |
| Ramshot Magnum | <<locked>> | 94% | 54,839 psi | 86% | 3209 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,130 psi | 60% | 2083 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,145 psi | 60% | 2087 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 82% | 54,447 psi | 85% | 3166 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 82% | 54,578 psi | 86% | 3169 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 84% | 56,797 psi | 89% | 3255 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 84% | 57,159 psi | 90% | 3261 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 96% | 54,360 psi | 85% | 3317 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 96% | 54,708 psi | 86% | 3323 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 98% | 53,664 psi | 84% | 3268 fps | 98.4% |
| ReloadSwiss RS 80 | <<locked>> | 98% | 53,998 psi | 85% | 3274 fps | 98.5% |
| Rottweil R 904 | <<locked>> | 88% | 56,130 psi | 88% | 3173 fps | 99.2% |
| Rottweil R 904 | <<locked>> | 88% | 56,246 psi | 88% | 3179 fps | 99.2% |
| Rottweil R 905 | <<locked>> | 88% | 54,433 psi | 85% | 3186 fps | 99.7% |
| Rottweil R 905 | <<locked>> | 88% | 54,578 psi | 86% | 3189 fps | 99.7% |
| Rottweil R 907 | <<locked>> | 82% | 56,043 psi | 88% | 3143 fps | 99.9% |
| Rottweil R 907 | <<locked>> | 82% | 56,159 psi | 88% | 3146 fps | 100% |
| Shooters World Long Rifle | <<locked>> | 82% | 54,766 psi | 86% | 3107 fps | 100% |
| Shooters World Long Rifle | <<locked>> | 82% | 54,897 psi | 86% | 3110 fps | 100% |
| Shooters World SW4350 | <<locked>> | 84% | 56,579 psi | 89% | 3163 fps | 100% |
| Shooters World SW4350 | <<locked>> | 84% | 56,710 psi | 89% | 3163 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 84% | 57,435 psi | 90% | 3114 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 84% | 57,537 psi | 90% | 3117 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 88% | 54,027 psi | 85% | 3179 fps | 99.6% |
| SNPE Vectan Tubal 8000 | <<locked>> | 88% | 54,172 psi | 85% | 3182 fps | 99.6% |
| Somchem S361 | <<locked>> | 86% | 54,041 psi | 85% | 3100 fps | 98.4% |
| Somchem S361 | <<locked>> | 86% | 54,346 psi | 85% | 3110 fps | 98.5% |
| Somchem S365 | <<locked>> | 86% | 57,246 psi | 90% | 3182 fps | 100% |
| Somchem S365 | <<locked>> | 86% | 57,682 psi | 90% | 3189 fps | 100% |
| Somchem S385 | <<locked>> | 88% | 54,810 psi | 86% | 3153 fps | 99.9% |
| Somchem S385 | <<locked>> | 88% | 55,201 psi | 87% | 3159 fps | 99.9% |
| Vihtavuori N160 | <<locked>> | 82% | 54,201 psi | 85% | 3114 fps | 100% |
| Vihtavuori N160 | <<locked>> | 82% | 54,592 psi | 86% | 3117 fps | 100% |
| Vihtavuori N165 | <<locked>> | 92% | 54,723 psi | 86% | 3136 fps | 99.8% |
| Vihtavuori N165 | <<locked>> | 92% | 54,795 psi | 86% | 3136 fps | 99.8% |
| Vihtavuori N550 | <<locked>> | 84% | 57,101 psi | 89% | 3176 fps | 100% |
| Vihtavuori N550 | <<locked>> | 84% | 57,479 psi | 90% | 3182 fps | 100% |
| Vihtavuori N555 | <<locked>> | 90% | 57,116 psi | 90% | 3209 fps | 100% |
| Vihtavuori N555 | <<locked>> | 90% | 57,493 psi | 90% | 3215 fps | 100% |
| Vihtavuori N560 | <<locked>> | 90% | 56,927 psi | 89% | 3291 fps | 99.1% |
| Vihtavuori N560 | <<locked>> | 90% | 57,276 psi | 90% | 3301 fps | 99.1% |
| Vihtavuori N565 | <<locked>> | 96% | 57,319 psi | 90% | 3274 fps | 99.3% |
| Vihtavuori N565 | <<locked>> | 96% | 57,696 psi | 90% | 3281 fps | 99.3% |
| Vihtavuori N568 | <<locked>> | 98% | 54,636 psi | 86% | 3274 fps | 98.1% |
| Vihtavuori N568 | <<locked>> | 98% | 54,984 psi | 86% | 3284 fps | 98.2% |
| Vihtavuori N570ᴾ | <<locked>> | 100% | 55,608 psi | 87% | 3340 fps | 96.6% |
| Vihtavuori N570ᴾ | <<locked>> | 100% | 55,927 psi | 88% | 3343 fps | 96.7% |
| Winchester 6.5 StaBALL | <<locked>> | 84% | 57,464 psi | 90% | 3117 fps | 100% |
| Winchester 6.5 StaBALL | <<locked>> | 82% | 54,027 psi | 85% | 3064 fps | 100% |
| Winchester 760 | <<locked>> | 82% | 55,927 psi | 88% | 3202 fps | 100% |
| Winchester 760 | <<locked>> | 82% | 56,289 psi | 88% | 3209 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 92% | 53,838 psi | 84% | 3268 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 92% | 54,346 psi | 85% | 3274 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 90% | 54,694 psi | 86% | 3146 fps | 99.6% |
| Winchester Supreme 780 | <<locked>> | 90% | 55,056 psi | 86% | 3153 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% | 38,145 psi | 60% | 2808 fps | 98.7% |
| Accurate 3100 | <<locked>> | 80% | 38,450 psi | 60% | 2818 fps | 98.8% |
| Accurate 4350 | <<locked>> | 80% | 50,647 psi | 79% | 3081 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 51,053 psi | 80% | 3091 fps | 100% |
| Accurate High Country | <<locked>> | 80% | 41,640 psi | 65% | 2995 fps | 96.4% |
| Accurate High Country | <<locked>> | 80% | 41,756 psi | 65% | 3002 fps | 96.5% |
| Accurate MAGPRO | <<locked>> | 82% | 42,250 psi | 66% | 2995 fps | 95.2% |
| Accurate MAGPRO | <<locked>> | 82% | 42,380 psi | 66% | 3002 fps | 95.3% |
| ADI AR 2209 | <<locked>> | 80% | 42,076 psi | 66% | 2949 fps | 97.5% |
| ADI AR 2209 | <<locked>> | 80% | 42,424 psi | 66% | 2956 fps | 97.7% |
| ADI AR 2213 | <<locked>> | 82% | 40,437 psi | 63% | 2943 fps | 95.8% |
| ADI AR 2213 | <<locked>> | 82% | 40,538 psi | 64% | 2946 fps | 95.9% |
| ADI AR 2217 | <<locked>> | 90% | 39,247 psi | 62% | 2907 fps | 95.8% |
| ADI AR 2217 | <<locked>> | 90% | 39,349 psi | 62% | 2910 fps | 95.9% |
| ADI AR 2225 | <<locked>> | 86% | 31,154 psi | 49% | 2733 fps | 95.5% |
| ADI AR 2225 | <<locked>> | 86% | 31,241 psi | 49% | 2736 fps | 95.6% |
| Alliant Power Pro Varmint | <<locked>> | 80% | 42,496 psi | 67% | 2953 fps | 97.7% |
| Alliant Power Pro Varmint | <<locked>> | 80% | 42,496 psi | 67% | 2949 fps | 97.7% |
| Alliant Power Pro Varmint | <<locked>> | 80% | 42,830 psi | 67% | 2959 fps | 97.8% |
| Alliant Reloder-16 | <<locked>> | 80% | 48,544 psi | 76% | 3087 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 80% | 48,689 psi | 76% | 3094 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 42,119 psi | 66% | 2943 fps | 97.6% |
| Alliant Reloder-19 | <<locked>> | 80% | 42,438 psi | 67% | 2953 fps | 97.7% |
| Alliant Reloder-22 | <<locked>> | 80% | 38,203 psi | 60% | 2887 fps | 96.6% |
| Alliant Reloder-22 | <<locked>> | 80% | 38,319 psi | 60% | 2890 fps | 96.6% |
| Alliant Reloder-23 | <<locked>> | 80% | 36,782 psi | 58% | 2838 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 80% | 36,941 psi | 58% | 2841 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 31,778 psi | 50% | 2746 fps | 97.7% |
| Alliant Reloder-25 | <<locked>> | 80% | 32,053 psi | 50% | 2753 fps | 97.8% |
| Alliant Reloder-26 | <<locked>> | 80% | 41,118 psi | 64% | 3002 fps | 99.9% |
| Alliant Reloder-26 | <<locked>> | 80% | 41,278 psi | 65% | 3009 fps | 99.9% |
| Alliant Reloder-33 | <<locked>> | 98% | 48,472 psi | 76% | 3176 fps | 95.1% |
| Alliant Reloder-33 | <<locked>> | 98% | 48,762 psi | 76% | 3182 fps | 95.2% |
| Baschieri & Pellagri 109 | <<locked>> | 88% | 48,109 psi | 75% | 3041 fps | 95.1% |
| Baschieri & Pellagri 109 | <<locked>> | 88% | 48,356 psi | 76% | 3045 fps | 95.2% |
| Bofors RP15 | <<locked>> | 80% | 35,418 psi | 56% | 2812 fps | 95.3% |
| Bofors RP15 | <<locked>> | 80% | 35,723 psi | 56% | 2822 fps | 95.5% |
| Bofors RP30 | <<locked>> | 88% | 38,769 psi | 61% | 2927 fps | 96% |
| Bofors RP30 | <<locked>> | 86% | 36,289 psi | 57% | 2861 fps | 95% |
| Bofors RP5 | <<locked>> | 80% | 38,203 psi | 60% | 2887 fps | 96.6% |
| Bofors RP5 | <<locked>> | 80% | 38,319 psi | 60% | 2890 fps | 96.6% |
| Bofors RP7 | <<locked>> | 80% | 52,547 psi | 82% | 3084 fps | 99.8% |
| Bofors RP7 | <<locked>> | 80% | 52,692 psi | 83% | 3087 fps | 99.8% |
| Hodgdon H1000 | <<locked>> | 86% | 37,304 psi | 58% | 2861 fps | 95.7% |
| Hodgdon H1000 | <<locked>> | 86% | 37,579 psi | 59% | 2867 fps | 95.9% |
| Hodgdon H414 | <<locked>> | 80% | 52,156 psi | 82% | 3140 fps | 99.9% |
| Hodgdon H414 | <<locked>> | 80% | 52,301 psi | 82% | 3143 fps | 99.9% |
| Hodgdon H4831 | <<locked>> | 80% | 40,176 psi | 63% | 2881 fps | 95% |
| Hodgdon H4831 | <<locked>> | 80% | 40,277 psi | 63% | 2884 fps | 95.1% |
| Hodgdon H4831 SC | <<locked>> | 82% | 42,366 psi | 66% | 2930 fps | 95.8% |
| Hodgdon H4831 SC | <<locked>> | 82% | 42,482 psi | 67% | 2933 fps | 95.9% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 45,672 psi | 72% | 2956 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 45,803 psi | 72% | 2959 fps | 100% |
| Hodgdon Retumbo | 58.2 gr | 82% | 33,315 psi | 52% | 2835 fps | 95.1% |
| Hodgdon Retumbo | 58.2 gr | 82% | 33,446 psi | 52% | 2841 fps | 95.2% |
| Hodgdon Superformance | <<locked>> | 80% | 52,605 psi | 82% | 3173 fps | 99.9% |
| Hodgdon Superformance | <<locked>> | 80% | 52,707 psi | 83% | 3176 fps | 99.9% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,094 psi | 44% | 1827 fps | 100% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,949 psi | 44% | 1827 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 47,834 psi | 75% | 3009 fps | 99.4% |
| IMR 4350 | <<locked>> | 80% | 48,167 psi | 75% | 3015 fps | 99.4% |
| IMR 4451 Enduron | <<locked>> | 80% | 53,925 psi | 85% | 3110 fps | 99.9% |
| IMR 4451 Enduron | <<locked>> | 80% | 54,070 psi | 85% | 3110 fps | 100% |
| IMR 4831 | <<locked>> | 80% | 48,066 psi | 75% | 3022 fps | 100% |
| IMR 4831 | <<locked>> | 80% | 48,211 psi | 76% | 3025 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 41,611 psi | 65% | 2881 fps | 95.7% |
| IMR 4955 Enduron | <<locked>> | 80% | 41,916 psi | 66% | 2887 fps | 95.9% |
| IMR 7828 SSC | <<locked>> | 82% | 38,972 psi | 61% | 2917 fps | 95.4% |
| IMR 7828 SSC | <<locked>> | 82% | 39,102 psi | 61% | 2920 fps | 95.4% |
| IMR 8133 Enduron | <<locked>> | 94% | 36,709 psi | 58% | 2894 fps | 95% |
| IMR 8133 Enduron | <<locked>> | 94% | 37,028 psi | 58% | 2900 fps | 95.1% |
| Lovex S065 | <<locked>> | 80% | 51,416 psi | 81% | 3051 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 51,547 psi | 81% | 3054 fps | 100% |
| Lovex S070 | <<locked>> | 80% | 49,806 psi | 78% | 3045 fps | 99.8% |
| Lovex S070 | <<locked>> | 80% | 50,169 psi | 79% | 3051 fps | 99.9% |
| Lovex S071 | <<locked>> | 80% | 32,895 psi | 52% | 2677 fps | 97.2% |
| Lovex S071 | <<locked>> | 80% | 33,054 psi | 52% | 2684 fps | 97.3% |
| Norma 204 | <<locked>> | 80% | 48,443 psi | 76% | 3061 fps | 98.7% |
| Norma 204 | <<locked>> | 80% | 48,544 psi | 76% | 3061 fps | 98.8% |
| Norma 217 | <<locked>> | 90% | 32,242 psi | 51% | 2792 fps | 95.5% |
| Norma 217 | <<locked>> | 90% | 32,503 psi | 51% | 2799 fps | 95.6% |
| Norma MRP | <<locked>> | 80% | 40,190 psi | 63% | 2959 fps | 98.4% |
| Norma MRP | <<locked>> | 80% | 40,350 psi | 63% | 2963 fps | 98.4% |
| Norma URP | <<locked>> | 80% | 49,342 psi | 77% | 3064 fps | 100% |
| Norma URP | <<locked>> | 80% | 49,734 psi | 78% | 3071 fps | 100% |
| Ramshot Grand | <<locked>> | 82% | 38,812 psi | 61% | 2927 fps | 95.8% |
| Ramshot Grand | <<locked>> | 82% | 38,943 psi | 61% | 2930 fps | 95.9% |
| Ramshot Hunter | <<locked>> | 80% | 48,399 psi | 76% | 3068 fps | 99.9% |
| Ramshot Hunter | <<locked>> | 80% | 48,515 psi | 76% | 3071 fps | 99.9% |
| Ramshot Magnum | <<locked>> | 80% | 32,285 psi | 51% | 2723 fps | 95.2% |
| Ramshot Magnum | <<locked>> | 80% | 32,401 psi | 51% | 2726 fps | 95.2% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,631 psi | 45% | 1870 fps | 100% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,689 psi | 45% | 1873 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 50,763 psi | 80% | 3104 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 51,140 psi | 80% | 3110 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 49,081 psi | 77% | 3127 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 49,197 psi | 77% | 3130 fps | 100% |
| ReloadSwiss RS 76 | 62.3 gr | 82% | 32,387 psi | 51% | 2802 fps | 96.1% |
| ReloadSwiss RS 76 | 62.3 gr | 82% | 32,634 psi | 51% | 2812 fps | 96.3% |
| ReloadSwiss RS 80 | <<locked>> | 92% | 42,714 psi | 67% | 3048 fps | 95.7% |
| ReloadSwiss RS 80 | <<locked>> | 92% | 42,830 psi | 67% | 3051 fps | 95.8% |
| Rottweil R 904 | <<locked>> | 80% | 43,250 psi | 68% | 2927 fps | 96.8% |
| Rottweil R 904 | <<locked>> | 80% | 43,540 psi | 68% | 2933 fps | 96.9% |
| Rottweil R 905 | <<locked>> | 80% | 41,582 psi | 65% | 2930 fps | 97.6% |
| Rottweil R 905 | <<locked>> | 80% | 41,727 psi | 65% | 2933 fps | 97.7% |
| Rottweil R 907 | <<locked>> | 80% | 52,547 psi | 82% | 3084 fps | 99.8% |
| Rottweil R 907 | <<locked>> | 80% | 52,692 psi | 83% | 3087 fps | 99.8% |
| Shooters World Long Rifle | <<locked>> | 80% | 51,416 psi | 81% | 3051 fps | 100% |
| Shooters World Long Rifle | <<locked>> | 80% | 51,547 psi | 81% | 3054 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 49,806 psi | 78% | 3045 fps | 99.8% |
| Shooters World SW4350 | <<locked>> | 80% | 50,169 psi | 79% | 3051 fps | 99.9% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 50,473 psi | 79% | 2999 fps | 99.8% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 50,618 psi | 79% | 3002 fps | 99.8% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 41,278 psi | 65% | 2927 fps | 97.5% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 41,394 psi | 65% | 2930 fps | 97.6% |
| Somchem S361 | <<locked>> | 80% | 44,150 psi | 69% | 2913 fps | 96.3% |
| Somchem S361 | <<locked>> | 80% | 44,266 psi | 69% | 2913 fps | 96.4% |
| Somchem S365 | <<locked>> | 80% | 46,673 psi | 73% | 3012 fps | 100% |
| Somchem S365 | <<locked>> | 80% | 47,079 psi | 74% | 3022 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 42,250 psi | 66% | 2913 fps | 98.5% |
| Somchem S385 | <<locked>> | 80% | 42,380 psi | 66% | 2913 fps | 98.5% |
| Vihtavuori N160 | <<locked>> | 80% | 50,749 psi | 80% | 3054 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 51,111 psi | 80% | 3061 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 36,564 psi | 57% | 2769 fps | 96.6% |
| Vihtavuori N165 | <<locked>> | 80% | 36,869 psi | 58% | 2779 fps | 96.7% |
| Vihtavuori N550 | <<locked>> | 80% | 50,285 psi | 79% | 3064 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 50,415 psi | 79% | 3064 fps | 100% |
| Vihtavuori N555 | <<locked>> | 80% | 41,075 psi | 64% | 2923 fps | 100% |
| Vihtavuori N555 | <<locked>> | 80% | 41,423 psi | 65% | 2930 fps | 100% |
| Vihtavuori N560 | <<locked>> | 80% | 40,147 psi | 63% | 2949 fps | 95.2% |
| Vihtavuori N560 | <<locked>> | 80% | 40,292 psi | 63% | 2953 fps | 95.3% |
| Vihtavuori N565 | <<locked>> | 86% | 40,727 psi | 64% | 2943 fps | 95.7% |
| Vihtavuori N565 | <<locked>> | 86% | 41,060 psi | 64% | 2953 fps | 95.9% |
| Vihtavuori N568 | <<locked>> | 92% | 43,816 psi | 69% | 3061 fps | 95.4% |
| Vihtavuori N568 | <<locked>> | 92% | 44,106 psi | 69% | 3064 fps | 95.5% |
| Vihtavuori N570 | <<locked>> | 98% | 51,561 psi | 81% | 3261 fps | 95.6% |
| Vihtavuori N570 | <<locked>> | 98% | 51,909 psi | 81% | 3268 fps | 95.7% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 50,082 psi | 78% | 3005 fps | 100% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 50,444 psi | 79% | 3012 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 52,402 psi | 82% | 3143 fps | 99.9% |
| Winchester 760 | <<locked>> | 80% | 52,533 psi | 82% | 3143 fps | 99.9% |
| Winchester StaBALL HD | 58.3 gr | 80% | 33,620 psi | 53% | 2874 fps | 100% |
| Winchester StaBALL HD | 58.3 gr | 80% | 33,823 psi | 53% | 2881 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 38,609 psi | 61% | 2828 fps | 96.6% |
| Winchester Supreme 780 | <<locked>> | 80% | 38,899 psi | 61% | 2835 fps | 96.7% |
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 145 powders for .257 Weath. Mag. loaded with the .257 | 115gr | Berger VLD Hunting. Hodgdon Retumbo delivers the highest muzzle velocity at 3,399 fps; across all powders the maximum-charge window runs from 2,041 fps to 3,399 fps. ADI AR 2217 gives the best case fill at 100 %, and 145 of the 145 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (440 MPa), the top charges use 59–90 %, 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 2217, 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, Winchester StaBALL HD rank at the top here: for .257 Weath. Mag. with the .257 | 115gr | Berger VLD Hunting 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.