Load Specifications
Load data in caliber .257 Weath. Mag. with .257 | 70gr | CutEdge ESP Raptor bullet and 91 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Alliant Reloder-16, ReloadSwiss RS 70 and Alliant Reloder-26.
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 2495 | <<locked>> | 84% | 56,565 psi | 89% | 3734 fps | 100% |
| Accurate 2700 | <<locked>> | 84% | 54,911 psi | 86% | 3720 fps | 96.9% |
| Accurate 3100ᴾ | <<locked>> | 100% | 53,635 psi | 84% | 3743 fps | 98.3% |
| Accurate 4064 | <<locked>> | 86% | 56,927 psi | 89% | 3789 fps | 100% |
| Accurate 4350 | <<locked>> | 92% | 55,201 psi | 87% | 3832 fps | 99.5% |
| ADI AR 2206H | <<locked>> | 82% | 56,333 psi | 88% | 3835 fps | 99.9% |
| ADI AR 2208 | <<locked>> | 86% | 54,317 psi | 85% | 3770 fps | 99.6% |
| ADI AR 2209 | <<locked>> | 98% | 56,840 psi | 89% | 3875 fps | 96.5% |
| Alliant Power Pro 2000-MR | <<locked>> | 84% | 57,682 psi | 90% | 3983 fps | 99.9% |
| Alliant Power Pro Varmint | <<locked>> | 98% | 56,985 psi | 89% | 3868 fps | 96.6% |
| Alliant Power Pro Varmint | <<locked>> | 98% | 56,985 psi | 89% | 3868 fps | 96.6% |
| Alliant Reloder- TS 15.5 | <<locked>> | 86% | 54,911 psi | 86% | 3796 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 84% | 54,940 psi | 86% | 3819 fps | 99.7% |
| Alliant Reloder-16 | <<locked>> | 94% | 55,927 psi | 88% | 3911 fps | 99.8% |
| Alliant Reloder-17 | <<locked>> | 88% | 53,693 psi | 84% | 3871 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 98% | 56,144 psi | 88% | 3855 fps | 96.5% |
| Alliant Reloder-22ᴾ | <<locked>> | 100% | 53,650 psi | 84% | 3842 fps | 96.1% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 50,386 psi | 79% | 3773 fps | 99.9% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 43,845 psi | 69% | 3638 fps | 96.9% |
| Alliant Reloder-26 | <<locked>> | 98% | 54,955 psi | 86% | 3934 fps | 99.6% |
| Baschieri & Pellagri 107 | <<locked>> | 82% | 56,869 psi | 89% | 3839 fps | 99.7% |
| Bofors RP3 | <<locked>> | 86% | 55,782 psi | 87% | 3812 fps | 100% |
| Bofors RP5ᴾ | <<locked>> | 100% | 53,650 psi | 84% | 3842 fps | 96.1% |
| Bofors RP7 | <<locked>> | 90% | 55,506 psi | 87% | 3780 fps | 97.2% |
| Hodgdon H380 | <<locked>> | 86% | 56,362 psi | 88% | 3825 fps | 99.3% |
| Hodgdon H414 | <<locked>> | 92% | 57,682 psi | 90% | 3894 fps | 98.2% |
| Hodgdon H4350 | <<locked>> | 90% | 57,174 psi | 90% | 3852 fps | 96.9% |
| Hodgdon H4895 | <<locked>> | 82% | 56,971 psi | 89% | 3848 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 96% | 56,405 psi | 88% | 3816 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 82% | 53,911 psi | 84% | 3812 fps | 100% |
| Hodgdon Superformance | <<locked>> | 90% | 54,665 psi | 86% | 3852 fps | 97.5% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 35,853 psi | 56% | 2546 fps | 100% |
| Hodgdon VARGET | <<locked>> | 82% | 54,578 psi | 86% | 3783 fps | 100% |
| IMR 3031 | <<locked>> | 82% | 57,290 psi | 90% | 3835 fps | 100% |
| IMR 4064 | <<locked>> | 86% | 57,159 psi | 90% | 3819 fps | 99.9% |
| IMR 4166 Enduron | <<locked>> | 84% | 56,492 psi | 89% | 3786 fps | 97.9% |
| IMR 4350 | <<locked>> | 94% | 56,913 psi | 89% | 3812 fps | 97.6% |
| IMR 4451 Enduron | <<locked>> | 90% | 57,305 psi | 90% | 3819 fps | 98% |
| IMR 4831 | <<locked>> | 94% | 55,782 psi | 87% | 3819 fps | 99.6% |
| IMR 4895 | <<locked>> | 84% | 56,420 psi | 88% | 3858 fps | 99.9% |
| Lovex D073.6 | <<locked>> | 82% | 56,768 psi | 89% | 3796 fps | 100% |
| Lovex S060 | <<locked>> | 82% | 54,969 psi | 86% | 3747 fps | 99.9% |
| Lovex S062 | <<locked>> | 86% | 57,116 psi | 90% | 3809 fps | 100% |
| Lovex S065 | <<locked>> | 92% | 57,246 psi | 90% | 3809 fps | 99% |
| Lovex S070 | <<locked>> | 92% | 55,013 psi | 86% | 3783 fps | 97.9% |
| Lovex S071ᴾ | <<locked>> | 100% | 43,976 psi | 69% | 3533 fps | 96.1% |
| Norma 201 | <<locked>> | 82% | 54,592 psi | 86% | 3763 fps | 100% |
| Norma 202 | <<locked>> | 82% | 55,608 psi | 87% | 3770 fps | 100% |
| Norma 203B | <<locked>> | 84% | 54,244 psi | 85% | 3802 fps | 99.8% |
| Norma MRPᴾ | <<locked>> | 100% | 57,522 psi | 90% | 3953 fps | 98.3% |
| Norma URP | <<locked>> | 92% | 53,853 psi | 84% | 3816 fps | 99.3% |
| Ramshot Big Game | <<locked>> | 84% | 55,622 psi | 87% | 3825 fps | 99.9% |
| Ramshot Hunter | <<locked>> | 94% | 56,898 psi | 89% | 3875 fps | 98.8% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 36,419 psi | 57% | 2602 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 86% | 56,536 psi | 89% | 3802 fps | 98.4% |
| ReloadSwiss RS 52 | <<locked>> | 82% | 55,941 psi | 88% | 3904 fps | 99.7% |
| ReloadSwiss RS 60 | <<locked>> | 88% | 57,159 psi | 90% | 3947 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 92% | 55,419 psi | 87% | 3848 fps | 99.4% |
| ReloadSwiss RS 70 | <<locked>> | 92% | 54,215 psi | 85% | 3881 fps | 99.3% |
| Rottweil R 902 | <<locked>> | 84% | 55,376 psi | 87% | 3763 fps | 100% |
| Rottweil R 903 | <<locked>> | 88% | 55,854 psi | 88% | 3802 fps | 100% |
| Rottweil R 905 | <<locked>> | 98% | 55,347 psi | 87% | 3835 fps | 96.4% |
| Rottweil R 907 | <<locked>> | 90% | 55,506 psi | 87% | 3780 fps | 97.2% |
| Shooters World Long Rifle | <<locked>> | 92% | 57,246 psi | 90% | 3809 fps | 99% |
| Shooters World Match Rifle | <<locked>> | 82% | 56,768 psi | 89% | 3796 fps | 100% |
| Shooters World Precision | <<locked>> | 86% | 57,116 psi | 90% | 3809 fps | 100% |
| Shooters World SW4350 | <<locked>> | 92% | 55,013 psi | 86% | 3783 fps | 97.9% |
| SNPE Vectan SP 11 | <<locked>> | 86% | 54,186 psi | 85% | 3806 fps | 99.8% |
| SNPE Vectan SP 9 | <<locked>> | 82% | 54,839 psi | 86% | 3786 fps | 99.9% |
| SNPE Vectan Tubal 3000 | <<locked>> | 82% | 55,622 psi | 87% | 3698 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 88% | 57,029 psi | 89% | 3688 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 92% | 57,261 psi | 90% | 3747 fps | 98.1% |
| SNPE Vectan Tubal 8000 | <<locked>> | 98% | 54,868 psi | 86% | 3829 fps | 96.3% |
| Somchem S335 | <<locked>> | 82% | 55,201 psi | 87% | 3681 fps | 100% |
| Somchem S355 | <<locked>> | 88% | 55,825 psi | 87% | 3802 fps | 100% |
| Somchem S365 | <<locked>> | 96% | 57,159 psi | 90% | 3885 fps | 100% |
| Somchem S385 | <<locked>> | 98% | 56,028 psi | 88% | 3802 fps | 97.4% |
| Vihtavuori N133 | <<locked>> | 82% | 56,159 psi | 88% | 3678 fps | 100% |
| Vihtavuori N135 | <<locked>> | 84% | 55,738 psi | 87% | 3727 fps | 100% |
| Vihtavuori N140 | <<locked>> | 84% | 56,463 psi | 88% | 3737 fps | 100% |
| Vihtavuori N150 | <<locked>> | 90% | 57,653 psi | 90% | 3773 fps | 100% |
| Vihtavuori N160 | <<locked>> | 92% | 56,217 psi | 88% | 3812 fps | 99.5% |
| Vihtavuori N165ᴾ | <<locked>> | 100% | 51,837 psi | 81% | 3691 fps | 96.1% |
| Vihtavuori N540 | <<locked>> | 84% | 54,795 psi | 86% | 3720 fps | 100% |
| Vihtavuori N550 | <<locked>> | 92% | 55,564 psi | 87% | 3812 fps | 99.4% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 56,144 psi | 88% | 3875 fps | 99.9% |
| Winchester 6.5 StaBALL | <<locked>> | 92% | 56,782 psi | 89% | 3773 fps | 100% |
| Winchester 760 | <<locked>> | 90% | 54,056 psi | 85% | 3822 fps | 97.5% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 45,730 psi | 72% | 3816 fps | 100% |
| Winchester StaBALL Match | <<locked>> | 82% | 55,317 psi | 87% | 3796 fps | 100% |
| Winchester Supreme 780ᴾ | <<locked>> | 100% | 56,840 psi | 89% | 3799 fps | 96.6% |
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 2495 | <<locked>> | 80% | 49,197 psi | 77% | 3606 fps | 100% |
| Accurate 2700 | <<locked>> | 80% | 47,993 psi | 75% | 3576 fps | 95.1% |
| Accurate 3100 | <<locked>> | 94% | 43,105 psi | 68% | 3510 fps | 95.8% |
| Accurate 4064 | <<locked>> | 80% | 46,601 psi | 73% | 3599 fps | 100% |
| Accurate 4350 | <<locked>> | 82% | 38,116 psi | 60% | 3438 fps | 95.7% |
| ADI AR 2206H | <<locked>> | 80% | 52,678 psi | 83% | 3763 fps | 99.7% |
| ADI AR 2208 | <<locked>> | 80% | 44,469 psi | 70% | 3556 fps | 98.2% |
| ADI AR 2209 | <<locked>> | 96% | 52,968 psi | 83% | 3793 fps | 95.5% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 49,472 psi | 78% | 3812 fps | 99.1% |
| Alliant Power Pro Varmint | <<locked>> | 96% | 53,113 psi | 83% | 3793 fps | 95.7% |
| Alliant Power Pro Varmint | <<locked>> | 96% | 53,113 psi | 83% | 3793 fps | 95.7% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 44,846 psi | 70% | 3586 fps | 99.3% |
| Alliant Reloder-15 | <<locked>> | 80% | 48,109 psi | 75% | 3675 fps | 98.9% |
| Alliant Reloder-16 | 59.2 gr | 82% | 37,202 psi | 58% | 3458 fps | 95.7% |
| Alliant Reloder-17 | <<locked>> | 80% | 39,755 psi | 62% | 3550 fps | 98.3% |
| Alliant Reloder-19 | <<locked>> | 96% | 52,388 psi | 82% | 3776 fps | 95.6% |
| Alliant Reloder-22 | <<locked>> | 98% | 49,893 psi | 78% | 3757 fps | 95% |
| Alliant Reloder-23 | <<locked>> | 88% | 33,112 psi | 52% | 3320 fps | 95.8% |
| Alliant Reloder-25 | <<locked>> | 98% | 40,843 psi | 64% | 3556 fps | 95.8% |
| Alliant Reloder-26 | 71.7 gr | 90% | 39,827 psi | 62% | 3576 fps | 96.2% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 52,968 psi | 83% | 3766 fps | 99.3% |
| Bofors RP3 | <<locked>> | 80% | 45,063 psi | 71% | 3589 fps | 99.4% |
| Bofors RP5 | <<locked>> | 98% | 49,893 psi | 78% | 3757 fps | 95% |
| Bofors RP7 | <<locked>> | 86% | 48,443 psi | 76% | 3629 fps | 95.5% |
| Hodgdon H380 | <<locked>> | 80% | 45,774 psi | 72% | 3599 fps | 97.5% |
| Hodgdon H414 | <<locked>> | 86% | 46,746 psi | 73% | 3661 fps | 95.7% |
| Hodgdon H4350 | <<locked>> | 86% | 49,908 psi | 78% | 3698 fps | 95.1% |
| Hodgdon H4895 | <<locked>> | 80% | 53,243 psi | 83% | 3780 fps | 99.9% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 32,024 psi | 50% | 3238 fps | 95.3% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 50,053 psi | 78% | 3734 fps | 99.9% |
| Hodgdon Superformance | <<locked>> | 86% | 46,862 psi | 73% | 3678 fps | 95.4% |
| Hodgdon TrailBoss | <<locked>> | 80% | 26,629 psi | 42% | 2293 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 50,981 psi | 80% | 3714 fps | 99.8% |
| IMR 3031 | <<locked>> | 80% | 53,577 psi | 84% | 3770 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 46,731 psi | 73% | 3606 fps | 98.8% |
| IMR 4166 Enduron | <<locked>> | 80% | 49,414 psi | 77% | 3638 fps | 96.4% |
| IMR 4350 | <<locked>> | 88% | 46,659 psi | 73% | 3593 fps | 95% |
| IMR 4451 Enduron | <<locked>> | 84% | 47,108 psi | 74% | 3599 fps | 95.6% |
| IMR 4831 | <<locked>> | 82% | 36,666 psi | 57% | 3376 fps | 95.3% |
| IMR 4895 | <<locked>> | 80% | 49,385 psi | 77% | 3717 fps | 99.4% |
| Lovex D073.6 | <<locked>> | 80% | 52,939 psi | 83% | 3727 fps | 100% |
| Lovex S060 | <<locked>> | 80% | 51,634 psi | 81% | 3678 fps | 99.7% |
| Lovex S062 | <<locked>> | 80% | 46,963 psi | 74% | 3609 fps | 99.7% |
| Lovex S065 | <<locked>> | 82% | 41,162 psi | 65% | 3451 fps | 95.4% |
| Lovex S070 | <<locked>> | 86% | 45,049 psi | 71% | 3563 fps | 95.4% |
| Lovex S071 | <<locked>> | 98% | 41,017 psi | 64% | 3458 fps | 95% |
| Norma 201 | <<locked>> | 80% | 51,198 psi | 80% | 3698 fps | 100% |
| Norma 202 | <<locked>> | 80% | 51,938 psi | 81% | 3704 fps | 100% |
| Norma 203B | <<locked>> | 80% | 47,500 psi | 74% | 3661 fps | 99.2% |
| Norma MRP | <<locked>> | 94% | 45,934 psi | 72% | 3701 fps | 95.4% |
| Norma URP | <<locked>> | 82% | 37,971 psi | 60% | 3438 fps | 95.6% |
| Ramshot Big Game | <<locked>> | 80% | 48,022 psi | 75% | 3671 fps | 99.2% |
| Ramshot Hunter | <<locked>> | 86% | 42,873 psi | 67% | 3566 fps | 95.5% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,021 psi | 42% | 2346 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 45,963 psi | 72% | 3576 fps | 96.1% |
| ReloadSwiss RS 52 | <<locked>> | 80% | 52,083 psi | 82% | 3825 fps | 99.4% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 42,351 psi | 66% | 3638 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 82% | 38,261 psi | 60% | 3455 fps | 95.4% |
| ReloadSwiss RS 70 | 66.3 gr | 84% | 40,263 psi | 63% | 3543 fps | 95.8% |
| Rottweil R 902 | <<locked>> | 80% | 48,733 psi | 76% | 3635 fps | 99.8% |
| Rottweil R 903 | <<locked>> | 80% | 42,177 psi | 66% | 3514 fps | 98.7% |
| Rottweil R 905 | <<locked>> | 96% | 51,474 psi | 81% | 3757 fps | 95.5% |
| Rottweil R 907 | <<locked>> | 86% | 48,443 psi | 76% | 3629 fps | 95.5% |
| Shooters World Long Rifle | <<locked>> | 82% | 41,162 psi | 65% | 3451 fps | 95.4% |
| Shooters World Match Rifle | <<locked>> | 80% | 52,939 psi | 83% | 3727 fps | 100% |
| Shooters World Precision | <<locked>> | 80% | 46,963 psi | 74% | 3609 fps | 99.7% |
| Shooters World SW4350 | <<locked>> | 86% | 45,049 psi | 71% | 3563 fps | 95.4% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 43,787 psi | 69% | 3579 fps | 98.5% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 51,300 psi | 80% | 3714 fps | 99.6% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 52,127 psi | 82% | 3638 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 43,918 psi | 69% | 3448 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 86% | 46,688 psi | 73% | 3530 fps | 95.8% |
| SNPE Vectan Tubal 8000 | <<locked>> | 96% | 51,010 psi | 80% | 3747 fps | 95.3% |
| Somchem S335 | <<locked>> | 80% | 51,909 psi | 81% | 3622 fps | 100% |
| Somchem S355 | <<locked>> | 80% | 42,714 psi | 67% | 3524 fps | 98.7% |
| Somchem S365 | <<locked>> | 80% | 31,836 psi | 50% | 3291 fps | 96.8% |
| Somchem S385 | <<locked>> | 94% | 48,689 psi | 76% | 3652 fps | 95.7% |
| Vihtavuori N133 | <<locked>> | 80% | 52,678 psi | 83% | 3622 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 48,820 psi | 77% | 3606 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 49,240 psi | 77% | 3609 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 40,785 psi | 64% | 3435 fps | 99.3% |
| Vihtavuori N160 | <<locked>> | 80% | 36,825 psi | 58% | 3366 fps | 95.1% |
| Vihtavuori N165 | <<locked>> | 98% | 48,240 psi | 76% | 3615 fps | 95.1% |
| Vihtavuori N540 | <<locked>> | 80% | 47,921 psi | 75% | 3593 fps | 100% |
| Vihtavuori N550 | <<locked>> | 82% | 39,146 psi | 61% | 3438 fps | 95.8% |
| Vihtavuori N555 | <<locked>> | 88% | 36,666 psi | 57% | 3422 fps | 95.9% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 36,535 psi | 57% | 3327 fps | 97.7% |
| Winchester 760 | <<locked>> | 86% | 46,978 psi | 74% | 3665 fps | 95.7% |
| Winchester StaBALL HD | <<locked>> | 90% | 31,720 psi | 50% | 3356 fps | 96% |
| Winchester StaBALL Match | <<locked>> | 80% | 51,416 psi | 81% | 3724 fps | 99.9% |
| Winchester Supreme 780 | <<locked>> | 98% | 52,750 psi | 83% | 3720 fps | 95.6% |
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 91 powders for .257 Weath. Mag. loaded with the .257 | 70gr | CutEdge ESP Raptor. Alliant Power Pro 2000-MR delivers the highest muzzle velocity at 3,983 fps; across all powders the maximum-charge window runs from 2,546 fps to 3,983 fps. Accurate 3100 gives the best case fill at 100 %, and 91 of the 91 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (440 MPa), the top charges use 56–90 %, leaving at least 10 % headroom. The 70.0 gr projectile in 0.257" calls for a 1:12.0 twist; slower twists will usually not stabilise this weight. Accurate 3100, Alliant Reloder-22, Alliant Reloder-23 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. Alliant Reloder-16, ReloadSwiss RS 70, Alliant Reloder-26 rank at the top here: for .257 Weath. Mag. with the .257 | 70gr | CutEdge ESP Raptor 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.