Load Specifications
Bullet:.257 | 90gr | Hornady CX
Bullet Manufacturer:Hornady
Bullet Weight:90 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:1:10.5
Load data in caliber .257 Weath. Mag. with .257 | 90gr | Hornady CX bullet and 156 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.
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>> | 96% | 55,158 psi | 86% | 3465 fps | 99.8% |
| Accurate 3100 | <<locked>> | 96% | 56,188 psi | 88% | 3481 fps | 99.8% |
| Accurate 4350 | <<locked>> | 88% | 56,391 psi | 88% | 3524 fps | 100% |
| Accurate 4350 | <<locked>> | 88% | 57,305 psi | 90% | 3540 fps | 100% |
| Accurate High Country | <<locked>> | 94% | 56,898 psi | 89% | 3635 fps | 97.9% |
| Accurate High Country | <<locked>> | 92% | 53,998 psi | 85% | 3583 fps | 97.4% |
| Accurate MAGPRO | <<locked>> | 94% | 55,143 psi | 86% | 3579 fps | 96.4% |
| ADI AR 2208 | <<locked>> | 82% | 54,273 psi | 85% | 3435 fps | 100% |
| ADI AR 2208 | <<locked>> | 82% | 54,897 psi | 86% | 3451 fps | 100% |
| ADI AR 2209 | <<locked>> | 92% | 53,838 psi | 84% | 3510 fps | 98.1% |
| ADI AR 2209 | <<locked>> | 92% | 54,853 psi | 86% | 3533 fps | 98.4% |
| ADI AR 2213 | <<locked>> | 96% | 55,680 psi | 87% | 3573 fps | 97.4% |
| ADI AR 2213 | <<locked>> | 96% | 56,623 psi | 89% | 3596 fps | 97.7% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 41,104 psi | 64% | 3287 fps | 97.1% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 42,032 psi | 66% | 3320 fps | 97.6% |
| Alliant Power Pro Varmint | <<locked>> | 92% | 54,143 psi | 85% | 3507 fps | 98.2% |
| Alliant Power Pro Varmint | <<locked>> | 92% | 55,143 psi | 86% | 3530 fps | 98.4% |
| Alliant Reloder- TS 15.5 | <<locked>> | 82% | 55,158 psi | 86% | 3458 fps | 100% |
| Alliant Reloder- TS 15.5 | <<locked>> | 82% | 56,086 psi | 88% | 3478 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 90% | 57,319 psi | 90% | 3593 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 88% | 54,549 psi | 85% | 3550 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 84% | 54,969 psi | 86% | 3547 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 84% | 55,898 psi | 88% | 3566 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 94% | 57,276 psi | 90% | 3563 fps | 98.7% |
| Alliant Reloder-19 | <<locked>> | 92% | 54,462 psi | 85% | 3517 fps | 98.3% |
| Alliant Reloder-22 | <<locked>> | 96% | 55,376 psi | 87% | 3570 fps | 98.5% |
| Alliant Reloder-22 | <<locked>> | 96% | 56,376 psi | 88% | 3589 fps | 98.8% |
| Alliant Reloder-23 | <<locked>> | 98% | 56,231 psi | 88% | 3547 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 98% | 57,334 psi | 90% | 3563 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 52,011 psi | 82% | 3530 fps | 99.9% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 53,229 psi | 83% | 3560 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 94% | 57,174 psi | 90% | 3645 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 92% | 54,128 psi | 85% | 3593 fps | 100% |
| Bofors RP15 | <<locked>> | 98% | 54,273 psi | 85% | 3543 fps | 98.2% |
| Bofors RP15 | <<locked>> | 98% | 55,259 psi | 87% | 3563 fps | 98.5% |
| Bofors RP3 | <<locked>> | 82% | 56,362 psi | 88% | 3478 fps | 100% |
| Bofors RP3 | <<locked>> | 82% | 57,043 psi | 89% | 3491 fps | 100% |
| Bofors RP30ᴾ | <<locked>> | 100% | 47,906 psi | 75% | 3435 fps | 96.3% |
| Bofors RP30ᴾ | <<locked>> | 100% | 49,153 psi | 77% | 3465 fps | 96.7% |
| Bofors RP5 | <<locked>> | 96% | 55,376 psi | 87% | 3570 fps | 98.5% |
| Bofors RP5 | <<locked>> | 96% | 56,376 psi | 88% | 3589 fps | 98.8% |
| Bofors RP7 | <<locked>> | 86% | 55,550 psi | 87% | 3465 fps | 99% |
| Bofors RP7 | <<locked>> | 86% | 56,376 psi | 88% | 3484 fps | 99.2% |
| Hodgdon H1000ᴾ | <<locked>> | 100% | 51,213 psi | 80% | 3468 fps | 97.4% |
| Hodgdon H1000ᴾ | <<locked>> | 100% | 52,315 psi | 82% | 3497 fps | 97.8% |
| Hodgdon H380 | <<locked>> | 82% | 56,449 psi | 88% | 3494 fps | 100% |
| Hodgdon H380 | <<locked>> | 82% | 57,348 psi | 90% | 3517 fps | 100% |
| Hodgdon H414 | <<locked>> | 86% | 54,752 psi | 86% | 3520 fps | 99.3% |
| Hodgdon H414 | <<locked>> | 86% | 55,564 psi | 87% | 3537 fps | 99.4% |
| Hodgdon H4350 | <<locked>> | 86% | 57,493 psi | 90% | 3537 fps | 98.8% |
| Hodgdon H4350 | <<locked>> | 84% | 54,549 psi | 85% | 3488 fps | 98.5% |
| Hodgdon H4831 | <<locked>> | 94% | 55,390 psi | 87% | 3501 fps | 96.7% |
| Hodgdon H4831 | <<locked>> | 94% | 56,347 psi | 88% | 3524 fps | 97% |
| Hodgdon H4831 SC | <<locked>> | 94% | 54,360 psi | 85% | 3481 fps | 96.5% |
| Hodgdon H4831 SC | <<locked>> | 94% | 55,317 psi | 87% | 3504 fps | 96.8% |
| Hodgdon Hybrid 100V | <<locked>> | 92% | 57,682 psi | 90% | 3497 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 90% | 54,824 psi | 86% | 3458 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 50,952 psi | 80% | 3589 fps | 98.6% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 52,112 psi | 82% | 3622 fps | 99% |
| Hodgdon Superformance | <<locked>> | 86% | 55,376 psi | 87% | 3550 fps | 99.3% |
| Hodgdon Superformance | <<locked>> | 86% | 56,405 psi | 88% | 3570 fps | 99.4% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,506 psi | 57% | 2283 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,666 psi | 57% | 2293 fps | 100% |
| IMR 4064 | <<locked>> | 82% | 57,101 psi | 89% | 3474 fps | 100% |
| IMR 4350 | <<locked>> | 90% | 57,290 psi | 90% | 3504 fps | 99.3% |
| IMR 4350 | <<locked>> | 88% | 54,549 psi | 85% | 3461 fps | 99% |
| IMR 4451 Enduron | <<locked>> | 86% | 57,203 psi | 90% | 3497 fps | 99.4% |
| IMR 4451 Enduron | <<locked>> | 84% | 54,331 psi | 85% | 3451 fps | 99.2% |
| IMR 4831 | <<locked>> | 90% | 56,811 psi | 89% | 3510 fps | 100% |
| IMR 4831 | <<locked>> | 88% | 54,085 psi | 85% | 3468 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 94% | 56,652 psi | 89% | 3491 fps | 97.1% |
| IMR 4955 Enduron | <<locked>> | 94% | 57,566 psi | 90% | 3514 fps | 97.4% |
| IMR 7828 SSC | <<locked>> | 98% | 57,188 psi | 90% | 3615 fps | 97.8% |
| IMR 7828 SSC | <<locked>> | 96% | 54,143 psi | 85% | 3563 fps | 97.3% |
| Lovex S062 | <<locked>> | 82% | 57,319 psi | 90% | 3465 fps | 100% |
| Lovex S065 | <<locked>> | 88% | 57,551 psi | 90% | 3491 fps | 99.9% |
| Lovex S065 | <<locked>> | 86% | 54,607 psi | 86% | 3445 fps | 99.8% |
| Lovex S070 | <<locked>> | 88% | 55,637 psi | 87% | 3481 fps | 99.5% |
| Lovex S070 | <<locked>> | 88% | 56,420 psi | 88% | 3497 fps | 99.6% |
| Lovex S071ᴾ | <<locked>> | 100% | 52,518 psi | 82% | 3419 fps | 99.6% |
| Lovex S071ᴾ | <<locked>> | 100% | 53,563 psi | 84% | 3438 fps | 99.7% |
| Norma 204 | <<locked>> | 88% | 54,679 psi | 86% | 3497 fps | 98.1% |
| Norma 204 | <<locked>> | 88% | 55,448 psi | 87% | 3514 fps | 98.3% |
| Norma MRP | <<locked>> | 94% | 55,056 psi | 86% | 3593 fps | 99.4% |
| Norma MRP | <<locked>> | 94% | 56,376 psi | 88% | 3619 fps | 99.6% |
| Norma URP | <<locked>> | 88% | 54,940 psi | 86% | 3504 fps | 100% |
| Norma URP | <<locked>> | 88% | 55,811 psi | 87% | 3524 fps | 100% |
| Ramshot Grand | <<locked>> | 96% | 53,708 psi | 84% | 3556 fps | 97.5% |
| Ramshot Grand | <<locked>> | 96% | 54,998 psi | 86% | 3586 fps | 97.9% |
| Ramshot Hunter | <<locked>> | 88% | 54,056 psi | 85% | 3501 fps | 99.6% |
| Ramshot Hunter | <<locked>> | 88% | 54,824 psi | 86% | 3517 fps | 99.7% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 56,768 psi | 89% | 3560 fps | 99.3% |
| Ramshot Magnum | <<locked>> | 98% | 53,417 psi | 84% | 3504 fps | 99% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,260 psi | 58% | 2336 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,405 psi | 59% | 2346 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 82% | 56,275 psi | 88% | 3478 fps | 99.7% |
| ReloadSwiss RS 50 | <<locked>> | 82% | 57,087 psi | 89% | 3494 fps | 99.8% |
| ReloadSwiss RS 60 | <<locked>> | 82% | 54,128 psi | 85% | 3537 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 82% | 55,158 psi | 86% | 3553 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 88% | 56,840 psi | 89% | 3547 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 88% | 57,711 psi | 90% | 3563 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 88% | 55,288 psi | 87% | 3579 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 88% | 56,130 psi | 88% | 3596 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 52,054 psi | 82% | 3589 fps | 99.6% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 53,127 psi | 83% | 3615 fps | 99.7% |
| Rottweil R 903 | <<locked>> | 84% | 56,463 psi | 88% | 3474 fps | 100% |
| Rottweil R 903 | <<locked>> | 84% | 57,406 psi | 90% | 3491 fps | 100% |
| Rottweil R 904 | <<locked>> | 92% | 55,347 psi | 87% | 3478 fps | 97.4% |
| Rottweil R 904 | <<locked>> | 92% | 56,072 psi | 88% | 3497 fps | 97.6% |
| Rottweil R 905 | <<locked>> | 94% | 56,405 psi | 88% | 3547 fps | 98.6% |
| Rottweil R 905 | <<locked>> | 94% | 57,493 psi | 90% | 3570 fps | 98.9% |
| Rottweil R 907 | <<locked>> | 86% | 55,550 psi | 87% | 3465 fps | 99% |
| Rottweil R 907 | <<locked>> | 86% | 56,376 psi | 88% | 3484 fps | 99.2% |
| Shooters World Long Rifle | <<locked>> | 88% | 57,551 psi | 90% | 3491 fps | 99.9% |
| Shooters World Long Rifle | <<locked>> | 86% | 54,607 psi | 86% | 3445 fps | 99.8% |
| Shooters World Precision | <<locked>> | 82% | 57,319 psi | 90% | 3465 fps | 100% |
| Shooters World SW4350 | <<locked>> | 88% | 55,637 psi | 87% | 3481 fps | 99.5% |
| Shooters World SW4350 | <<locked>> | 88% | 56,420 psi | 88% | 3497 fps | 99.6% |
| SNPE Vectan SP 11 | <<locked>> | 82% | 54,737 psi | 86% | 3481 fps | 100% |
| SNPE Vectan SP 11 | <<locked>> | 82% | 55,361 psi | 87% | 3494 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 84% | 56,594 psi | 89% | 3337 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 84% | 57,464 psi | 90% | 3353 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 88% | 57,043 psi | 89% | 3432 fps | 99.5% |
| SNPE Vectan Tubal 7000 | <<locked>> | 86% | 54,230 psi | 85% | 3389 fps | 99.3% |
| SNPE Vectan Tubal 8000 | <<locked>> | 94% | 55,956 psi | 88% | 3540 fps | 98.6% |
| SNPE Vectan Tubal 8000 | <<locked>> | 94% | 57,043 psi | 89% | 3563 fps | 98.8% |
| Somchem S355 | <<locked>> | 84% | 56,101 psi | 88% | 3468 fps | 100% |
| Somchem S355 | <<locked>> | 84% | 57,014 psi | 89% | 3484 fps | 100% |
| Somchem S361 | <<locked>> | 92% | 57,319 psi | 90% | 3465 fps | 97.1% |
| Somchem S361 | <<locked>> | 90% | 54,201 psi | 85% | 3412 fps | 96.6% |
| Somchem S365 | <<locked>> | 90% | 55,172 psi | 86% | 3507 fps | 100% |
| Somchem S365 | <<locked>> | 90% | 56,115 psi | 88% | 3524 fps | 100% |
| Somchem S385 | <<locked>> | 94% | 57,087 psi | 89% | 3514 fps | 99.2% |
| Somchem S385 | <<locked>> | 92% | 54,244 psi | 85% | 3468 fps | 99% |
| Vihtavuori N150 | <<locked>> | 86% | 57,624 psi | 90% | 3435 fps | 100% |
| Vihtavuori N150 | <<locked>> | 84% | 54,882 psi | 86% | 3392 fps | 100% |
| Vihtavuori N160 | <<locked>> | 88% | 56,956 psi | 89% | 3501 fps | 100% |
| Vihtavuori N160 | <<locked>> | 86% | 53,940 psi | 85% | 3451 fps | 100% |
| Vihtavuori N165 | <<locked>> | 98% | 56,898 psi | 89% | 3491 fps | 99% |
| Vihtavuori N165 | <<locked>> | 96% | 53,940 psi | 85% | 3442 fps | 98.7% |
| Vihtavuori N550 | <<locked>> | 88% | 56,173 psi | 88% | 3501 fps | 100% |
| Vihtavuori N550 | <<locked>> | 88% | 56,956 psi | 89% | 3517 fps | 100% |
| Vihtavuori N555 | <<locked>> | 94% | 54,520 psi | 85% | 3514 fps | 100% |
| Vihtavuori N555 | <<locked>> | 94% | 55,637 psi | 87% | 3533 fps | 100% |
| Vihtavuori N560 | <<locked>> | 94% | 55,013 psi | 86% | 3579 fps | 96.9% |
| Vihtavuori N560 | <<locked>> | 94% | 56,260 psi | 88% | 3606 fps | 97.3% |
| Vihtavuori N565ᴾ | <<locked>> | 100% | 54,766 psi | 86% | 3543 fps | 97.1% |
| Vihtavuori N565ᴾ | <<locked>> | 100% | 55,999 psi | 88% | 3570 fps | 97.5% |
| Winchester 6.5 StaBALL | <<locked>> | 88% | 57,087 psi | 89% | 3448 fps | 100% |
| Winchester 6.5 StaBALL | <<locked>> | 86% | 54,012 psi | 85% | 3402 fps | 100% |
| Winchester 760 | <<locked>> | 86% | 54,752 psi | 86% | 3520 fps | 99.3% |
| Winchester 760 | <<locked>> | 86% | 55,825 psi | 87% | 3540 fps | 99.5% |
| Winchester StaBALL HD | <<locked>> | 98% | 53,737 psi | 84% | 3625 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 98% | 55,317 psi | 87% | 3648 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 96% | 57,464 psi | 90% | 3510 fps | 98.7% |
| Winchester Supreme 780 | <<locked>> | 94% | 54,404 psi | 85% | 3458 fps | 98.3% |
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>> | 84% | 35,955 psi | 56% | 3045 fps | 95.8% |
| Accurate 3100 | <<locked>> | 82% | 34,084 psi | 53% | 2995 fps | 95.2% |
| Accurate 4350 | <<locked>> | 80% | 42,351 psi | 66% | 3241 fps | 99% |
| Accurate 4350 | <<locked>> | 80% | 43,033 psi | 67% | 3261 fps | 99.2% |
| Accurate High Country | <<locked>> | 88% | 45,774 psi | 72% | 3402 fps | 95.1% |
| Accurate High Country | <<locked>> | 88% | 46,572 psi | 73% | 3422 fps | 95.5% |
| Accurate MAGPRO | <<locked>> | 92% | 51,111 psi | 80% | 3497 fps | 95.3% |
| ADI AR 2208 | <<locked>> | 80% | 50,937 psi | 80% | 3373 fps | 100% |
| ADI AR 2208 | <<locked>> | 80% | 51,561 psi | 81% | 3389 fps | 100% |
| ADI AR 2209 | <<locked>> | 86% | 43,816 psi | 69% | 3294 fps | 95.6% |
| ADI AR 2209 | <<locked>> | 86% | 44,556 psi | 70% | 3314 fps | 95.9% |
| ADI AR 2213 | 68.7 gr | 92% | 48,167 psi | 75% | 3419 fps | 95.5% |
| ADI AR 2213 | 68.7 gr | 92% | 49,066 psi | 77% | 3442 fps | 95.9% |
| ADI AR 2225 | <<locked>> | 98% | 38,493 psi | 60% | 3215 fps | 96% |
| ADI AR 2225 | <<locked>> | 96% | 36,593 psi | 57% | 3159 fps | 95.2% |
| Alliant Power Pro Varmint | <<locked>> | 86% | 44,063 psi | 69% | 3291 fps | 95.7% |
| Alliant Power Pro Varmint | <<locked>> | 84% | 41,989 psi | 66% | 3245 fps | 95.1% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 51,764 psi | 81% | 3396 fps | 100% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 52,431 psi | 82% | 3412 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 80% | 40,683 psi | 64% | 3255 fps | 99.1% |
| Alliant Reloder-16 | <<locked>> | 80% | 41,510 psi | 65% | 3278 fps | 99.3% |
| Alliant Reloder-17 | <<locked>> | 80% | 47,282 psi | 74% | 3406 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 80% | 48,167 psi | 75% | 3425 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 86% | 43,598 psi | 68% | 3281 fps | 95.6% |
| Alliant Reloder-19 | <<locked>> | 84% | 41,524 psi | 65% | 3235 fps | 95% |
| Alliant Reloder-22 | <<locked>> | 88% | 41,698 psi | 65% | 3271 fps | 95.1% |
| Alliant Reloder-22 | <<locked>> | 88% | 42,467 psi | 67% | 3294 fps | 95.5% |
| Alliant Reloder-23 | <<locked>> | 80% | 29,994 psi | 47% | 2946 fps | 97.1% |
| Alliant Reloder-23 | <<locked>> | 80% | 30,501 psi | 48% | 2966 fps | 97.4% |
| Alliant Reloder-25 | <<locked>> | 88% | 34,374 psi | 54% | 3097 fps | 95.9% |
| Alliant Reloder-25 | <<locked>> | 86% | 32,764 psi | 51% | 3048 fps | 95.2% |
| Alliant Reloder-26 | <<locked>> | 80% | 32,692 psi | 51% | 3081 fps | 95.8% |
| Alliant Reloder-26 | <<locked>> | 80% | 33,402 psi | 52% | 3104 fps | 96.3% |
| Bofors RP15 | <<locked>> | 92% | 44,208 psi | 69% | 3330 fps | 95.8% |
| Bofors RP15 | <<locked>> | 90% | 42,061 psi | 66% | 3281 fps | 95.2% |
| Bofors RP3 | <<locked>> | 80% | 52,547 psi | 82% | 3412 fps | 100% |
| Bofors RP3 | <<locked>> | 80% | 53,214 psi | 83% | 3428 fps | 100% |
| Bofors RP30 | <<locked>> | 98% | 44,672 psi | 70% | 3363 fps | 95.3% |
| Bofors RP30 | <<locked>> | 98% | 45,629 psi | 72% | 3386 fps | 95.7% |
| Bofors RP5 | <<locked>> | 88% | 41,698 psi | 65% | 3271 fps | 95.1% |
| Bofors RP5 | <<locked>> | 88% | 42,467 psi | 67% | 3294 fps | 95.5% |
| Bofors RP7 | <<locked>> | 80% | 45,629 psi | 72% | 3264 fps | 97.2% |
| Bofors RP7 | <<locked>> | 80% | 46,195 psi | 72% | 3278 fps | 97.4% |
| Hodgdon H1000 | <<locked>> | 96% | 44,440 psi | 70% | 3317 fps | 95.4% |
| Hodgdon H1000 | <<locked>> | 96% | 45,223 psi | 71% | 3340 fps | 95.8% |
| Hodgdon H380 | <<locked>> | 80% | 52,692 psi | 83% | 3428 fps | 99.9% |
| Hodgdon H380 | <<locked>> | 80% | 53,563 psi | 84% | 3448 fps | 99.9% |
| Hodgdon H414 | <<locked>> | 80% | 44,382 psi | 70% | 3301 fps | 97.4% |
| Hodgdon H414 | <<locked>> | 80% | 44,976 psi | 70% | 3320 fps | 97.7% |
| Hodgdon H4350 | <<locked>> | 80% | 47,065 psi | 74% | 3327 fps | 96.8% |
| Hodgdon H4350 | <<locked>> | 80% | 47,645 psi | 75% | 3346 fps | 97.1% |
| Hodgdon H4831 | <<locked>> | 92% | 51,822 psi | 81% | 3432 fps | 95.8% |
| Hodgdon H4831 | <<locked>> | 90% | 48,921 psi | 77% | 3376 fps | 95.2% |
| Hodgdon H4831 SC | <<locked>> | 92% | 50,589 psi | 79% | 3406 fps | 95.5% |
| Hodgdon H4831 SC | <<locked>> | 92% | 51,561 psi | 81% | 3428 fps | 95.9% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 38,334 psi | 60% | 3123 fps | 99.4% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 38,972 psi | 61% | 3140 fps | 99.5% |
| Hodgdon Retumbo | <<locked>> | 94% | 41,263 psi | 65% | 3346 fps | 95.6% |
| Hodgdon Retumbo | <<locked>> | 94% | 42,105 psi | 66% | 3373 fps | 96.1% |
| Hodgdon Superformance | <<locked>> | 80% | 43,976 psi | 69% | 3314 fps | 97.1% |
| Hodgdon Superformance | <<locked>> | 80% | 44,701 psi | 70% | 3337 fps | 97.4% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,224 psi | 43% | 2051 fps | 100% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,311 psi | 43% | 2057 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 53,592 psi | 84% | 3415 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 41,118 psi | 64% | 3169 fps | 96% |
| IMR 4350 | <<locked>> | 80% | 41,872 psi | 66% | 3189 fps | 96.3% |
| IMR 4451 Enduron | <<locked>> | 80% | 47,224 psi | 74% | 3301 fps | 98% |
| IMR 4451 Enduron | <<locked>> | 80% | 47,776 psi | 75% | 3317 fps | 98.2% |
| IMR 4831 | <<locked>> | 80% | 40,451 psi | 63% | 3182 fps | 98.7% |
| IMR 4831 | <<locked>> | 80% | 41,075 psi | 64% | 3199 fps | 98.9% |
| IMR 4955 Enduron | <<locked>> | 90% | 49,719 psi | 78% | 3356 fps | 95.5% |
| IMR 4955 Enduron | <<locked>> | 88% | 47,369 psi | 74% | 3310 fps | 95% |
| IMR 7828 SSC | <<locked>> | 92% | 46,180 psi | 72% | 3386 fps | 95% |
| IMR 7828 SSC | <<locked>> | 92% | 47,108 psi | 74% | 3409 fps | 95.4% |
| Lovex S062 | <<locked>> | 80% | 53,780 psi | 84% | 3406 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 44,498 psi | 70% | 3235 fps | 98.5% |
| Lovex S065 | <<locked>> | 80% | 45,078 psi | 71% | 3255 fps | 98.7% |
| Lovex S070 | <<locked>> | 80% | 42,714 psi | 67% | 3209 fps | 97.2% |
| Lovex S070 | <<locked>> | 80% | 43,497 psi | 68% | 3232 fps | 97.5% |
| Lovex S071 | <<locked>> | 88% | 34,911 psi | 55% | 3015 fps | 95.4% |
| Lovex S071 | <<locked>> | 88% | 35,636 psi | 56% | 3041 fps | 95.8% |
| Norma 204 | <<locked>> | 82% | 44,222 psi | 69% | 3278 fps | 95.6% |
| Norma 204 | <<locked>> | 82% | 44,773 psi | 70% | 3294 fps | 95.9% |
| Norma MRP | 64.7 gr | 84% | 37,927 psi | 59% | 3205 fps | 95.2% |
| Norma MRP | 64.7 gr | 84% | 38,653 psi | 61% | 3225 fps | 95.6% |
| Norma URP | <<locked>> | 80% | 41,742 psi | 65% | 3232 fps | 98.8% |
| Norma URP | <<locked>> | 80% | 42,583 psi | 67% | 3255 fps | 99.1% |
| Ramshot Grand | <<locked>> | 92% | 46,151 psi | 72% | 3396 fps | 95.4% |
| Ramshot Grand | <<locked>> | 92% | 47,094 psi | 74% | 3419 fps | 95.9% |
| Ramshot Hunter | <<locked>> | 80% | 40,886 psi | 64% | 3215 fps | 97.3% |
| Ramshot Hunter | <<locked>> | 80% | 41,466 psi | 65% | 3235 fps | 97.6% |
| Ramshot Magnum | <<locked>> | 92% | 41,249 psi | 65% | 3238 fps | 96% |
| Ramshot Magnum | <<locked>> | 90% | 39,088 psi | 61% | 3186 fps | 95.3% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,775 psi | 44% | 2096 fps | 100% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,862 psi | 44% | 2106 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 52,620 psi | 82% | 3412 fps | 99.3% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 53,447 psi | 84% | 3428 fps | 99.5% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 50,241 psi | 79% | 3468 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 51,242 psi | 80% | 3488 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 42,337 psi | 66% | 3258 fps | 98.8% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 43,163 psi | 68% | 3281 fps | 99% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 41,017 psi | 64% | 3274 fps | 98.5% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 41,785 psi | 65% | 3297 fps | 98.7% |
| ReloadSwiss RS 76 | <<locked>> | 92% | 38,261 psi | 60% | 3245 fps | 95.7% |
| ReloadSwiss RS 76 | <<locked>> | 92% | 39,015 psi | 61% | 3271 fps | 96.2% |
| Rottweil R 903 | <<locked>> | 80% | 49,255 psi | 77% | 3346 fps | 100% |
| Rottweil R 903 | <<locked>> | 80% | 50,183 psi | 79% | 3369 fps | 100% |
| Rottweil R 904 | <<locked>> | 88% | 48,399 psi | 76% | 3340 fps | 95.7% |
| Rottweil R 904 | <<locked>> | 86% | 45,861 psi | 72% | 3291 fps | 95.1% |
| Rottweil R 905 | <<locked>> | 86% | 42,888 psi | 67% | 3261 fps | 95.5% |
| Rottweil R 905 | <<locked>> | 86% | 43,482 psi | 68% | 3281 fps | 95.8% |
| Rottweil R 907 | <<locked>> | 80% | 45,629 psi | 72% | 3264 fps | 97.2% |
| Rottweil R 907 | <<locked>> | 80% | 46,195 psi | 72% | 3278 fps | 97.4% |
| Shooters World Long Rifle | <<locked>> | 80% | 44,498 psi | 70% | 3235 fps | 98.5% |
| Shooters World Long Rifle | <<locked>> | 80% | 45,078 psi | 71% | 3255 fps | 98.7% |
| Shooters World Precision | <<locked>> | 80% | 53,780 psi | 84% | 3406 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 42,714 psi | 67% | 3209 fps | 97.2% |
| Shooters World SW4350 | <<locked>> | 80% | 43,497 psi | 68% | 3232 fps | 97.5% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 51,082 psi | 80% | 3415 fps | 100% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 51,735 psi | 81% | 3428 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 49,951 psi | 78% | 3232 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 50,589 psi | 79% | 3245 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 43,598 psi | 68% | 3169 fps | 97.4% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 44,164 psi | 69% | 3186 fps | 97.6% |
| SNPE Vectan Tubal 8000 | <<locked>> | 86% | 42,511 psi | 67% | 3258 fps | 95.4% |
| SNPE Vectan Tubal 8000 | <<locked>> | 86% | 43,120 psi | 68% | 3274 fps | 95.7% |
| Somchem S355 | <<locked>> | 80% | 49,356 psi | 77% | 3346 fps | 100% |
| Somchem S355 | <<locked>> | 80% | 50,024 psi | 78% | 3363 fps | 100% |
| Somchem S361 | <<locked>> | 88% | 49,908 psi | 78% | 3323 fps | 95.4% |
| Somchem S361 | <<locked>> | 88% | 50,517 psi | 79% | 3340 fps | 95.7% |
| Somchem S365 | <<locked>> | 80% | 38,421 psi | 60% | 3176 fps | 99.9% |
| Somchem S365 | <<locked>> | 80% | 39,305 psi | 62% | 3199 fps | 100% |
| Somchem S385 | <<locked>> | 84% | 40,437 psi | 63% | 3166 fps | 95.7% |
| Somchem S385 | <<locked>> | 82% | 38,363 psi | 60% | 3117 fps | 95% |
| Vihtavuori N150 | <<locked>> | 80% | 47,224 psi | 74% | 3258 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 48,066 psi | 75% | 3274 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 43,352 psi | 68% | 3235 fps | 99.1% |
| Vihtavuori N160 | <<locked>> | 80% | 43,961 psi | 69% | 3251 fps | 99.3% |
| Vihtavuori N165 | <<locked>> | 88% | 40,234 psi | 63% | 3150 fps | 95.3% |
| Vihtavuori N165 | <<locked>> | 88% | 40,915 psi | 64% | 3169 fps | 95.6% |
| Vihtavuori N550 | <<locked>> | 80% | 42,670 psi | 67% | 3228 fps | 98.9% |
| Vihtavuori N550 | <<locked>> | 80% | 43,439 psi | 68% | 3248 fps | 99.1% |
| Vihtavuori N555 | <<locked>> | 80% | 33,446 psi | 52% | 3035 fps | 97.1% |
| Vihtavuori N555 | <<locked>> | 80% | 34,098 psi | 53% | 3054 fps | 97.4% |
| Vihtavuori N560 | 69.4 gr | 92% | 51,198 psi | 80% | 3504 fps | 96% |
| Vihtavuori N560 | 69.4 gr | 90% | 48,617 psi | 76% | 3448 fps | 95.3% |
| Vihtavuori N565 | <<locked>> | 96% | 47,413 psi | 74% | 3392 fps | 95.2% |
| Vihtavuori N565 | <<locked>> | 96% | 48,341 psi | 76% | 3412 fps | 95.6% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 42,656 psi | 67% | 3189 fps | 100% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 43,366 psi | 68% | 3209 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 44,382 psi | 70% | 3301 fps | 97.4% |
| Winchester 760 | <<locked>> | 80% | 45,208 psi | 71% | 3323 fps | 97.7% |
| Winchester StaBALL HD | <<locked>> | 80% | 26,571 psi | 42% | 2907 fps | 96.1% |
| Winchester StaBALL HD | <<locked>> | 80% | 26,992 psi | 42% | 2930 fps | 96.6% |
| Winchester Supreme 780 | <<locked>> | 88% | 42,902 psi | 67% | 3219 fps | 95.4% |
| Winchester Supreme 780 | <<locked>> | 88% | 43,845 psi | 69% | 3245 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 156 powders for .257 Weath. Mag. loaded with the .257 | 90gr | Hornady CX. Winchester StaBALL HD delivers the highest muzzle velocity at 3,648 fps; across all powders the maximum-charge window runs from 2,283 fps to 3,648 fps. ADI AR 2225 gives the best case fill at 100 %, and 156 of the 156 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 1:10.5 twist; slower twists will usually not stabilise this weight. ADI AR 2225, ADI AR 2225, Alliant Reloder-25 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 | Hornady CX 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.