Load Specifications
Load data in caliber .257 Weath. Mag. with .257 | 90gr | Hammer Absolute Hammer bullet and 81 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Norma MRP, Vihtavuori N560 and ADI AR 2213.
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: 26"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2700 | <<locked>> | 82% | 57,740 psi | 90% | 3461 fps | 99.1% |
| Accurate 3100 | <<locked>> | 96% | 54,215 psi | 85% | 3448 fps | 99.7% |
| Accurate 4064 | <<locked>> | 82% | 57,145 psi | 90% | 3438 fps | 100% |
| Accurate 4350 | <<locked>> | 88% | 55,579 psi | 87% | 3510 fps | 100% |
| Accurate MAGPRO | <<locked>> | 96% | 57,290 psi | 90% | 3615 fps | 96.7% |
| ADI AR 2208 | <<locked>> | 84% | 57,043 psi | 89% | 3484 fps | 100% |
| ADI AR 2209 | <<locked>> | 94% | 56,884 psi | 89% | 3563 fps | 98.5% |
| ADI AR 2213 | <<locked>> | 96% | 54,781 psi | 86% | 3556 fps | 97.2% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 40,466 psi | 63% | 3268 fps | 96.7% |
| Alliant Reloder- TS 15.5 | <<locked>> | 82% | 54,621 psi | 86% | 3448 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 90% | 56,521 psi | 89% | 3579 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 84% | 53,896 psi | 84% | 3527 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 94% | 56,391 psi | 88% | 3547 fps | 98.5% |
| Alliant Reloder-22 | <<locked>> | 96% | 54,462 psi | 85% | 3550 fps | 98.3% |
| Alliant Reloder-23 | <<locked>> | 98% | 55,230 psi | 87% | 3530 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 51,184 psi | 80% | 3517 fps | 99.9% |
| Alliant Reloder-26 | <<locked>> | 94% | 55,883 psi | 88% | 3625 fps | 100% |
| Bofors RP15ᴾ | <<locked>> | 100% | 57,058 psi | 89% | 3596 fps | 98.6% |
| Bofors RP3 | <<locked>> | 82% | 55,506 psi | 87% | 3465 fps | 100% |
| Bofors RP5 | <<locked>> | 96% | 54,462 psi | 85% | 3550 fps | 98.3% |
| Bofors RP7 | <<locked>> | 86% | 54,839 psi | 86% | 3448 fps | 98.9% |
| Hodgdon H1000ᴾ | <<locked>> | 100% | 50,488 psi | 79% | 3448 fps | 97.1% |
| Hodgdon H380 | <<locked>> | 82% | 55,709 psi | 87% | 3481 fps | 100% |
| Hodgdon H414 | <<locked>> | 88% | 57,667 psi | 90% | 3570 fps | 99.5% |
| Hodgdon H4350 | <<locked>> | 86% | 56,753 psi | 89% | 3520 fps | 98.7% |
| Hodgdon H4831 | <<locked>> | 94% | 54,563 psi | 86% | 3484 fps | 96.4% |
| Hodgdon H4831 SC | <<locked>> | 96% | 57,508 psi | 90% | 3537 fps | 97% |
| Hodgdon Hybrid 100V | <<locked>> | 92% | 56,898 psi | 89% | 3484 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 50,111 psi | 79% | 3570 fps | 98.4% |
| Hodgdon Superformance | <<locked>> | 86% | 54,433 psi | 85% | 3530 fps | 99.1% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,492 psi | 57% | 2277 fps | 100% |
| IMR 4064 | <<locked>> | 82% | 56,318 psi | 88% | 3461 fps | 100% |
| IMR 4350 | <<locked>> | 90% | 56,376 psi | 88% | 3488 fps | 99.1% |
| IMR 4451 Enduron | <<locked>> | 86% | 56,521 psi | 89% | 3484 fps | 99.3% |
| IMR 4831 | <<locked>> | 90% | 56,057 psi | 88% | 3497 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 94% | 55,854 psi | 88% | 3474 fps | 96.9% |
| IMR 7828 SSC | <<locked>> | 98% | 56,304 psi | 88% | 3596 fps | 97.6% |
| Lovex S062 | <<locked>> | 82% | 56,478 psi | 89% | 3448 fps | 100% |
| Lovex S065 | <<locked>> | 88% | 56,855 psi | 89% | 3478 fps | 99.9% |
| Lovex S070 | <<locked>> | 88% | 54,955 psi | 86% | 3465 fps | 99.3% |
| Lovex S071ᴾ | <<locked>> | 100% | 51,576 psi | 81% | 3399 fps | 99.4% |
| Norma 203B | <<locked>> | 82% | 57,479 psi | 90% | 3514 fps | 100% |
| Norma 204 | <<locked>> | 90% | 57,725 psi | 90% | 3553 fps | 98.5% |
| Norma MRP | <<locked>> | 94% | 54,128 psi | 85% | 3573 fps | 99.2% |
| Norma URP | <<locked>> | 88% | 54,201 psi | 85% | 3488 fps | 100% |
| Ramshot Grand | <<locked>> | 98% | 57,058 psi | 89% | 3615 fps | 98.1% |
| Ramshot Hunter | <<locked>> | 90% | 56,942 psi | 89% | 3553 fps | 99.8% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 55,593 psi | 87% | 3537 fps | 99.1% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,246 psi | 58% | 2329 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 82% | 55,564 psi | 87% | 3461 fps | 99.6% |
| ReloadSwiss RS 60 | <<locked>> | 84% | 57,392 psi | 90% | 3586 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 88% | 55,825 psi | 87% | 3530 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 88% | 54,317 psi | 85% | 3560 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 51,039 psi | 80% | 3566 fps | 99.4% |
| Rottweil R 903 | <<locked>> | 84% | 55,666 psi | 87% | 3458 fps | 100% |
| Rottweil R 904 | <<locked>> | 92% | 54,447 psi | 85% | 3461 fps | 97.1% |
| Rottweil R 905 | <<locked>> | 94% | 55,709 psi | 87% | 3530 fps | 98.5% |
| Rottweil R 907 | <<locked>> | 86% | 54,839 psi | 86% | 3448 fps | 98.9% |
| Shooters World Long Rifle | <<locked>> | 88% | 56,855 psi | 89% | 3478 fps | 99.9% |
| Shooters World Precision | <<locked>> | 82% | 56,478 psi | 89% | 3448 fps | 100% |
| Shooters World SW4350 | <<locked>> | 88% | 54,955 psi | 86% | 3465 fps | 99.3% |
| SNPE Vectan SP 11 | <<locked>> | 82% | 53,969 psi | 85% | 3468 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 84% | 56,043 psi | 88% | 3327 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 88% | 56,405 psi | 88% | 3419 fps | 99.4% |
| SNPE Vectan Tubal 8000 | <<locked>> | 94% | 55,259 psi | 87% | 3527 fps | 98.4% |
| Somchem S355 | <<locked>> | 84% | 55,564 psi | 87% | 3455 fps | 100% |
| Somchem S361 | <<locked>> | 92% | 56,275 psi | 88% | 3442 fps | 96.8% |
| Somchem S365 | <<locked>> | 90% | 54,099 psi | 85% | 3488 fps | 100% |
| Somchem S385 | <<locked>> | 94% | 56,173 psi | 88% | 3497 fps | 99.1% |
| Vihtavuori N150 | <<locked>> | 86% | 57,145 psi | 90% | 3425 fps | 100% |
| Vihtavuori N160 | <<locked>> | 88% | 56,188 psi | 88% | 3484 fps | 100% |
| Vihtavuori N165 | <<locked>> | 98% | 55,782 psi | 87% | 3468 fps | 98.8% |
| Vihtavuori N540 | <<locked>> | 82% | 57,537 psi | 90% | 3422 fps | 100% |
| Vihtavuori N550 | <<locked>> | 88% | 55,201 psi | 87% | 3481 fps | 100% |
| Vihtavuori N555 | <<locked>> | 96% | 57,493 psi | 90% | 3563 fps | 100% |
| Vihtavuori N560 | <<locked>> | 94% | 54,099 psi | 85% | 3560 fps | 96.6% |
| Vihtavuori N565ᴾ | <<locked>> | 100% | 53,664 psi | 84% | 3524 fps | 96.8% |
| Winchester 6.5 StaBALL | <<locked>> | 88% | 56,202 psi | 88% | 3435 fps | 100% |
| Winchester 760 | <<locked>> | 86% | 54,027 psi | 85% | 3501 fps | 99.1% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 56,753 psi | 89% | 3678 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 96% | 56,623 psi | 89% | 3494 fps | 98.5% |
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 2700 | <<locked>> | 80% | 53,911 psi | 84% | 3389 fps | 98.6% |
| Accurate 3100 | <<locked>> | 84% | 35,331 psi | 55% | 3028 fps | 95.5% |
| Accurate 4064 | <<locked>> | 80% | 53,534 psi | 84% | 3383 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 41,568 psi | 65% | 3225 fps | 98.8% |
| Accurate MAGPRO | <<locked>> | 94% | 52,997 psi | 83% | 3533 fps | 95.6% |
| ADI AR 2208 | <<locked>> | 80% | 50,183 psi | 79% | 3356 fps | 100% |
| ADI AR 2209 | <<locked>> | 86% | 43,178 psi | 68% | 3274 fps | 95.2% |
| ADI AR 2213 | 66.9 gr | 92% | 47,572 psi | 75% | 3402 fps | 95.2% |
| ADI AR 2225 | <<locked>> | 98% | 37,681 psi | 59% | 3189 fps | 95.4% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 51,184 psi | 80% | 3386 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 80% | 40,132 psi | 63% | 3238 fps | 98.9% |
| Alliant Reloder-17 | <<locked>> | 80% | 46,456 psi | 73% | 3389 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 86% | 42,917 psi | 67% | 3264 fps | 95.3% |
| Alliant Reloder-22 | <<locked>> | 90% | 43,976 psi | 69% | 3327 fps | 95.8% |
| Alliant Reloder-23 | <<locked>> | 80% | 29,530 psi | 46% | 2927 fps | 96.8% |
| Alliant Reloder-25 | <<locked>> | 88% | 33,823 psi | 53% | 3077 fps | 95.6% |
| Alliant Reloder-26 | <<locked>> | 80% | 32,097 psi | 50% | 3061 fps | 95.5% |
| Bofors RP15 | <<locked>> | 92% | 43,366 psi | 68% | 3307 fps | 95.4% |
| Bofors RP3 | <<locked>> | 80% | 51,706 psi | 81% | 3396 fps | 100% |
| Bofors RP5 | <<locked>> | 90% | 43,976 psi | 69% | 3327 fps | 95.8% |
| Bofors RP7 | <<locked>> | 80% | 44,918 psi | 70% | 3245 fps | 96.9% |
| Hodgdon H1000 | <<locked>> | 96% | 43,743 psi | 69% | 3297 fps | 95% |
| Hodgdon H380 | <<locked>> | 80% | 52,156 psi | 82% | 3415 fps | 99.8% |
| Hodgdon H414 | <<locked>> | 80% | 43,671 psi | 68% | 3284 fps | 97.2% |
| Hodgdon H4350 | <<locked>> | 80% | 46,340 psi | 73% | 3310 fps | 96.6% |
| Hodgdon H4831 | <<locked>> | 92% | 50,952 psi | 80% | 3412 fps | 95.5% |
| Hodgdon H4831 SC | <<locked>> | 92% | 49,995 psi | 78% | 3392 fps | 95.2% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 37,594 psi | 59% | 3104 fps | 99.2% |
| Hodgdon Retumbo | <<locked>> | 94% | 40,553 psi | 64% | 3323 fps | 95.1% |
| Hodgdon Superformance | <<locked>> | 80% | 43,279 psi | 68% | 3297 fps | 96.8% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,282 psi | 43% | 2047 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 52,750 psi | 83% | 3399 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 40,654 psi | 64% | 3153 fps | 95.7% |
| IMR 4451 Enduron | <<locked>> | 80% | 46,514 psi | 73% | 3284 fps | 97.7% |
| IMR 4831 | <<locked>> | 80% | 39,740 psi | 62% | 3163 fps | 98.5% |
| IMR 4955 Enduron | <<locked>> | 90% | 48,936 psi | 77% | 3333 fps | 95.2% |
| IMR 7828 SSC | <<locked>> | 94% | 48,805 psi | 76% | 3445 fps | 95.7% |
| Lovex S062 | <<locked>> | 80% | 52,968 psi | 83% | 3392 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 43,990 psi | 69% | 3222 fps | 98.4% |
| Lovex S070 | <<locked>> | 80% | 42,221 psi | 66% | 3196 fps | 97% |
| Lovex S071 | <<locked>> | 88% | 34,258 psi | 54% | 2999 fps | 95% |
| Norma 203B | <<locked>> | 80% | 53,882 psi | 84% | 3451 fps | 100% |
| Norma 204 | <<locked>> | 82% | 43,555 psi | 68% | 3261 fps | 95.2% |
| Norma MRP | 64.5 gr | 86% | 40,161 psi | 63% | 3264 fps | 96% |
| Norma URP | <<locked>> | 80% | 41,191 psi | 65% | 3219 fps | 98.7% |
| Ramshot Grand | <<locked>> | 92% | 45,324 psi | 71% | 3373 fps | 95% |
| Ramshot Hunter | <<locked>> | 80% | 40,205 psi | 63% | 3199 fps | 97% |
| Ramshot Magnum | <<locked>> | 92% | 40,524 psi | 64% | 3219 fps | 95.6% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,818 psi | 44% | 2093 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 51,924 psi | 81% | 3392 fps | 99.2% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 49,371 psi | 77% | 3451 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 41,800 psi | 66% | 3245 fps | 98.7% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 40,364 psi | 63% | 3258 fps | 98.3% |
| ReloadSwiss RS 76 | <<locked>> | 92% | 37,637 psi | 59% | 3225 fps | 95.2% |
| Rottweil R 903 | <<locked>> | 80% | 48,704 psi | 76% | 3333 fps | 100% |
| Rottweil R 904 | <<locked>> | 88% | 47,761 psi | 75% | 3323 fps | 95.5% |
| Rottweil R 905 | <<locked>> | 86% | 42,206 psi | 66% | 3245 fps | 95.2% |
| Rottweil R 907 | <<locked>> | 80% | 44,918 psi | 70% | 3245 fps | 96.9% |
| Shooters World Long Rifle | <<locked>> | 80% | 43,990 psi | 69% | 3222 fps | 98.4% |
| Shooters World Precision | <<locked>> | 80% | 52,968 psi | 83% | 3392 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 42,221 psi | 66% | 3196 fps | 97% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 50,343 psi | 79% | 3399 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 49,371 psi | 77% | 3222 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 42,975 psi | 67% | 3153 fps | 97.1% |
| SNPE Vectan Tubal 8000 | <<locked>> | 86% | 41,829 psi | 66% | 3238 fps | 95.1% |
| Somchem S355 | <<locked>> | 80% | 48,791 psi | 76% | 3333 fps | 100% |
| Somchem S361 | <<locked>> | 88% | 49,139 psi | 77% | 3304 fps | 95% |
| Somchem S365 | <<locked>> | 80% | 37,840 psi | 59% | 3163 fps | 99.9% |
| Somchem S385 | <<locked>> | 84% | 39,798 psi | 62% | 3153 fps | 95.4% |
| Vihtavuori N150 | <<locked>> | 80% | 46,673 psi | 73% | 3245 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 42,598 psi | 67% | 3219 fps | 98.9% |
| Vihtavuori N165 | <<locked>> | 90% | 42,409 psi | 66% | 3199 fps | 95.9% |
| Vihtavuori N540 | <<locked>> | 80% | 54,056 psi | 85% | 3366 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 42,177 psi | 66% | 3215 fps | 98.7% |
| Vihtavuori N555 | <<locked>> | 80% | 32,938 psi | 52% | 3018 fps | 96.8% |
| Vihtavuori N560 | 69 gr | 92% | 50,314 psi | 79% | 3484 fps | 95.6% |
| Vihtavuori N565 | <<locked>> | 98% | 50,125 psi | 79% | 3448 fps | 95.9% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 42,032 psi | 66% | 3176 fps | 99.9% |
| Winchester 760 | <<locked>> | 80% | 43,859 psi | 69% | 3287 fps | 97.2% |
| Winchester StaBALL HD | <<locked>> | 80% | 26,078 psi | 41% | 2884 fps | 95.5% |
| Winchester Supreme 780 | <<locked>> | 88% | 42,322 psi | 66% | 3205 fps | 95.1% |
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 81 powders for .257 Weath. Mag. loaded with the .257 | 90gr | Hammer Absolute Hammer. Winchester StaBALL HD delivers the highest muzzle velocity at 3,678 fps; across all powders the maximum-charge window runs from 2,277 fps to 3,678 fps. ADI AR 2225 gives the best case fill at 100 %, and 81 of the 81 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 90.0 gr projectile in 0.257" calls for a 1:10.0 twist; slower twists will usually not stabilise this weight. ADI AR 2225, Alliant Reloder-25, Bofors RP15 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. Norma MRP, Vihtavuori N560, ADI AR 2213 rank at the top here: for .257 Weath. Mag. with the .257 | 90gr | Hammer Absolute Hammer 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.