Load Specifications
Bullet Manufacturer:Winchester
Bullet Weight:117 gr
Bullet Diameter:0.257"
Bullet Length:<<locked>>
Caliber:.25 WSSM load data
Case Length (l3):1.67"
Cartridge Length (C.O.L.):<<locked>>
Case Capacity:54.3 Grains of Water
Primer Size:Large Rifle (LR)
Barrel Length:24"
Max. allowed Pressure:63,817 psi
Recommended Twist Rate:1:12.5
Load data in caliber .25 WSSM with .257 | 117gr | Winchester SPRN bullet and 102 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are ReloadSwiss RS 70, Hodgdon Superformance and Alliant Reloder-17.
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: 24"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2015 | <<locked>> | 82% | 55,085 psi | 86% | 2766 fps | 100% |
| Accurate 2495 | <<locked>> | 86% | 54,244 psi | 85% | 2795 fps | 100% |
| Accurate 2520 | <<locked>> | 82% | 55,767 psi | 87% | 2861 fps | 100% |
| Accurate 2700 | <<locked>> | 88% | 56,289 psi | 88% | 2848 fps | 97.8% |
| Accurate 3100ᴾ | <<locked>> | 100% | 44,889 psi | 70% | 2756 fps | 97.4% |
| Accurate 4064 | <<locked>> | 88% | 54,389 psi | 85% | 2844 fps | 100% |
| Accurate 4350 | <<locked>> | 96% | 54,563 psi | 86% | 2940 fps | 99.8% |
| ADI AR 2206H | <<locked>> | 84% | 54,085 psi | 85% | 2871 fps | 100% |
| ADI AR 2208 | <<locked>> | 90% | 55,332 psi | 87% | 2877 fps | 100% |
| ADI AR 2209ᴾ | <<locked>> | 100% | 52,301 psi | 82% | 2907 fps | 96.2% |
| ADI Benchmark 8208 | <<locked>> | 84% | 56,376 psi | 88% | 2871 fps | 100% |
| Alliant AR-Comp | <<locked>> | 82% | 54,302 psi | 85% | 2795 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 86% | 53,853 psi | 84% | 2992 fps | 100% |
| Alliant Power Pro Varmintᴾ | <<locked>> | 100% | 52,199 psi | 82% | 2907 fps | 96.4% |
| Alliant Power Pro Varmintᴾ | <<locked>> | 100% | 52,199 psi | 82% | 2907 fps | 96.4% |
| Alliant Reloder- TS 15.5 | <<locked>> | 90% | 55,463 psi | 87% | 2894 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 88% | 56,115 psi | 88% | 2923 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 98% | 55,347 psi | 87% | 2992 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 94% | 56,536 psi | 89% | 3025 fps | 100% |
| Alliant Reloder-19ᴾ | <<locked>> | 100% | 51,459 psi | 81% | 2897 fps | 96.3% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 42,482 psi | 67% | 2785 fps | 99.7% |
| Alliant Reloder-26ᴾ | <<locked>> | 100% | 47,776 psi | 75% | 2956 fps | 99.3% |
| Baschieri & Pellagri 107 | <<locked>> | 84% | 54,114 psi | 85% | 2890 fps | 99.8% |
| Bofors RP3 | <<locked>> | 90% | 56,115 psi | 88% | 2910 fps | 100% |
| Bofors RP7 | <<locked>> | 94% | 55,970 psi | 88% | 2887 fps | 98% |
| Hodgdon Benchmark | <<locked>> | 82% | 54,853 psi | 86% | 2805 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 84% | 56,449 psi | 88% | 2907 fps | 100% |
| Hodgdon H380 | <<locked>> | 90% | 57,130 psi | 90% | 2930 fps | 99.8% |
| Hodgdon H414 | <<locked>> | 96% | 57,000 psi | 89% | 2986 fps | 98.7% |
| Hodgdon H4350 | <<locked>> | 94% | 57,334 psi | 90% | 2946 fps | 97.7% |
| Hodgdon H4895 | <<locked>> | 84% | 54,650 psi | 86% | 2881 fps | 100% |
| Hodgdon Hybrid 100Vᴾ | <<locked>> | 100% | 55,347 psi | 87% | 2913 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 86% | 54,389 psi | 85% | 2917 fps | 100% |
| Hodgdon Superformance | <<locked>> | 96% | 57,522 psi | 90% | 3025 fps | 98.5% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 35,926 psi | 56% | 1775 fps | 100% |
| Hodgdon VARGET | <<locked>> | 86% | 55,811 psi | 87% | 2884 fps | 100% |
| IMR 3031 | <<locked>> | 84% | 54,882 psi | 86% | 2861 fps | 100% |
| IMR 4064 | <<locked>> | 88% | 54,824 psi | 86% | 2858 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 86% | 54,679 psi | 86% | 2841 fps | 98.3% |
| IMR 4350 | <<locked>> | 98% | 56,449 psi | 88% | 2913 fps | 98.1% |
| IMR 4451 Enduron | <<locked>> | 92% | 54,462 psi | 85% | 2864 fps | 98.2% |
| IMR 4831 | <<locked>> | 98% | 54,897 psi | 86% | 2927 fps | 99.9% |
| IMR 4895 | <<locked>> | 88% | 57,566 psi | 90% | 2949 fps | 100% |
| IMR 8208 XBR | <<locked>> | 84% | 56,376 psi | 88% | 2871 fps | 100% |
| Lovex D073.6 | <<locked>> | 84% | 54,143 psi | 85% | 2848 fps | 100% |
| Lovex S060 | <<locked>> | 86% | 56,927 psi | 89% | 2848 fps | 100% |
| Lovex S062 | <<locked>> | 88% | 54,839 psi | 86% | 2854 fps | 100% |
| Lovex S065 | <<locked>> | 96% | 57,522 psi | 90% | 2910 fps | 99.5% |
| Lovex S070 | <<locked>> | 96% | 55,201 psi | 87% | 2900 fps | 98.6% |
| Norma 201 | <<locked>> | 86% | 56,420 psi | 88% | 2867 fps | 100% |
| Norma 202 | <<locked>> | 86% | 56,956 psi | 89% | 2864 fps | 100% |
| Norma 203B | <<locked>> | 88% | 55,317 psi | 87% | 2907 fps | 100% |
| Norma 204 | <<locked>> | 98% | 57,261 psi | 90% | 2966 fps | 97.1% |
| Norma MRPᴾ | <<locked>> | 100% | 47,630 psi | 75% | 2913 fps | 97% |
| Norma URP | <<locked>> | 98% | 56,913 psi | 89% | 2972 fps | 99.9% |
| Ramshot Big Game | <<locked>> | 88% | 55,898 psi | 88% | 2933 fps | 100% |
| Ramshot Hunter | <<locked>> | 98% | 55,477 psi | 87% | 2969 fps | 99.1% |
| Ramshot TAC | <<locked>> | 84% | 56,971 psi | 89% | 2900 fps | 99.5% |
| Ramshot Wild Boar | <<locked>> | 84% | 56,695 psi | 89% | 2913 fps | 100% |
| Ramshot X-Terminator | <<locked>> | 82% | 57,450 psi | 90% | 2877 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 36,477 psi | 57% | 1814 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 90% | 57,435 psi | 90% | 2913 fps | 99.1% |
| ReloadSwiss RS 52 | <<locked>> | 86% | 57,029 psi | 89% | 2992 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 92% | 56,463 psi | 88% | 3025 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 96% | 54,230 psi | 85% | 2959 fps | 99.7% |
| ReloadSwiss RS 70 | <<locked>> | 98% | 57,043 psi | 89% | 3045 fps | 99.8% |
| Rottweil R 901 | <<locked>> | 84% | 57,246 psi | 90% | 2844 fps | 100% |
| Rottweil R 902 | <<locked>> | 88% | 56,826 psi | 89% | 2864 fps | 100% |
| Rottweil R 903 | <<locked>> | 92% | 56,376 psi | 88% | 2907 fps | 100% |
| Rottweil R 905ᴾ | <<locked>> | 100% | 50,082 psi | 78% | 2877 fps | 96.2% |
| Rottweil R 907 | <<locked>> | 94% | 55,970 psi | 88% | 2887 fps | 98% |
| Shooters World Long Rifle | <<locked>> | 96% | 57,522 psi | 90% | 2910 fps | 99.5% |
| Shooters World Match Rifle | <<locked>> | 84% | 54,143 psi | 85% | 2848 fps | 100% |
| Shooters World Precision | <<locked>> | 88% | 54,839 psi | 86% | 2854 fps | 100% |
| Shooters World SW4350 | <<locked>> | 96% | 55,201 psi | 87% | 2900 fps | 98.6% |
| SNPE Vectan SP 11 | <<locked>> | 90% | 54,172 psi | 85% | 2913 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 84% | 55,637 psi | 87% | 2877 fps | 99.6% |
| SNPE Vectan SP 9 | <<locked>> | 86% | 56,318 psi | 88% | 2897 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 86% | 57,653 psi | 90% | 2799 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 90% | 54,897 psi | 86% | 2756 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 96% | 57,638 psi | 90% | 2864 fps | 98.6% |
| SNPE Vectan Tubal 8000ᴾ | <<locked>> | 100% | 49,588 psi | 78% | 2871 fps | 96% |
| Somchem S335 | <<locked>> | 86% | 57,101 psi | 89% | 2799 fps | 100% |
| Somchem S341 | <<locked>> | 84% | 55,129 psi | 86% | 2864 fps | 100% |
| Somchem S355 | <<locked>> | 92% | 56,362 psi | 88% | 2904 fps | 100% |
| Somchem S365ᴾ | <<locked>> | 100% | 54,998 psi | 86% | 2972 fps | 100% |
| Somchem S385ᴾ | <<locked>> | 100% | 51,039 psi | 80% | 2861 fps | 97.2% |
| Vihtavuori N130 | <<locked>> | 82% | 57,377 psi | 90% | 2759 fps | 100% |
| Vihtavuori N133 | <<locked>> | 84% | 54,853 psi | 86% | 2740 fps | 100% |
| Vihtavuori N135 | <<locked>> | 88% | 57,029 psi | 89% | 2825 fps | 100% |
| Vihtavuori N140 | <<locked>> | 88% | 57,464 psi | 90% | 2841 fps | 100% |
| Vihtavuori N150 | <<locked>> | 92% | 54,447 psi | 85% | 2831 fps | 100% |
| Vihtavuori N160 | <<locked>> | 96% | 55,898 psi | 88% | 2920 fps | 99.8% |
| Vihtavuori N530 | <<locked>> | 84% | 57,232 psi | 90% | 2874 fps | 100% |
| Vihtavuori N540 | <<locked>> | 88% | 55,883 psi | 88% | 2844 fps | 100% |
| Vihtavuori N550 | <<locked>> | 96% | 54,708 psi | 86% | 2920 fps | 99.7% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 47,108 psi | 74% | 2861 fps | 99.6% |
| Winchester 6.5 StaBALL | <<locked>> | 96% | 55,767 psi | 87% | 2890 fps | 100% |
| Winchester 748 | <<locked>> | 84% | 57,232 psi | 90% | 2917 fps | 100% |
| Winchester 760 | <<locked>> | 96% | 57,421 psi | 90% | 2992 fps | 98.8% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 38,159 psi | 60% | 2805 fps | 99.8% |
| Winchester StaBALL Match | <<locked>> | 86% | 56,159 psi | 88% | 2904 fps | 100% |
Recommended = one of the top powders for this cartridge and bullet combination.
Start Load - Barrel Length: 24"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2015 | <<locked>> | 80% | 51,721 psi | 81% | 2720 fps | 100% |
| Accurate 2495 | <<locked>> | 80% | 44,628 psi | 70% | 2651 fps | 100% |
| Accurate 2520 | <<locked>> | 80% | 51,953 psi | 81% | 2805 fps | 100% |
| Accurate 2700 | <<locked>> | 80% | 43,381 psi | 68% | 2628 fps | 95% |
| Accurate 3100 | <<locked>> | 96% | 39,204 psi | 61% | 2644 fps | 95.9% |
| Accurate 4064 | <<locked>> | 80% | 42,206 psi | 66% | 2651 fps | 100% |
| Accurate 4350 | <<locked>> | 82% | 33,460 psi | 52% | 2533 fps | 95.8% |
| ADI AR 2206H | <<locked>> | 80% | 47,790 psi | 75% | 2766 fps | 99.7% |
| ADI AR 2208 | <<locked>> | 80% | 40,553 psi | 64% | 2615 fps | 98.4% |
| ADI AR 2209 | <<locked>> | 98% | 49,037 psi | 77% | 2851 fps | 95.4% |
| ADI Benchmark 8208 | <<locked>> | 80% | 49,864 psi | 78% | 2769 fps | 100% |
| Alliant AR-Comp | <<locked>> | 80% | 50,807 psi | 80% | 2746 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 43,801 psi | 69% | 2812 fps | 99% |
| Alliant Power Pro Varmint | <<locked>> | 98% | 49,023 psi | 77% | 2851 fps | 95.6% |
| Alliant Power Pro Varmint | <<locked>> | 98% | 49,023 psi | 77% | 2851 fps | 95.6% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 40,553 psi | 64% | 2641 fps | 99.4% |
| Alliant Reloder-15 | <<locked>> | 80% | 43,453 psi | 68% | 2703 fps | 99% |
| Alliant Reloder-16 | <<locked>> | 80% | 31,604 psi | 50% | 2493 fps | 95% |
| Alliant Reloder-17 | 38.5 gr | 80% | 35,128 psi | 55% | 2618 fps | 98.2% |
| Alliant Reloder-19 | <<locked>> | 98% | 48,327 psi | 76% | 2841 fps | 95.5% |
| Alliant Reloder-23 | <<locked>> | 88% | 29,225 psi | 46% | 2454 fps | 95.7% |
| Alliant Reloder-26 | <<locked>> | 90% | 33,634 psi | 53% | 2635 fps | 95.1% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 47,195 psi | 74% | 2776 fps | 99.2% |
| Bofors RP3 | <<locked>> | 80% | 40,422 psi | 63% | 2644 fps | 99.5% |
| Bofors RP7 | <<locked>> | 86% | 43,656 psi | 68% | 2671 fps | 95.4% |
| Hodgdon Benchmark | <<locked>> | 80% | 51,605 psi | 81% | 2756 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 80% | 49,124 psi | 77% | 2795 fps | 100% |
| Hodgdon H380 | <<locked>> | 80% | 41,089 psi | 64% | 2651 fps | 97.6% |
| Hodgdon H414 | <<locked>> | 86% | 40,959 psi | 64% | 2700 fps | 95.3% |
| Hodgdon H4350 | <<locked>> | 88% | 47,340 psi | 74% | 2779 fps | 95.6% |
| Hodgdon H4895 | <<locked>> | 80% | 48,254 psi | 76% | 2776 fps | 99.9% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 28,935 psi | 45% | 2388 fps | 95.8% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 44,367 psi | 70% | 2753 fps | 99.9% |
| Hodgdon Superformance | 44.8 gr | 88% | 43,395 psi | 68% | 2776 fps | 95.5% |
| Hodgdon TrailBoss | <<locked>> | 80% | 26,789 psi | 42% | 1585 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 46,296 psi | 73% | 2726 fps | 99.8% |
| IMR 3031 | <<locked>> | 80% | 48,472 psi | 76% | 2766 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 42,612 psi | 67% | 2648 fps | 98.9% |
| IMR 4166 Enduron | <<locked>> | 80% | 45,194 psi | 71% | 2674 fps | 96.4% |
| IMR 4350 | <<locked>> | 90% | 44,121 psi | 69% | 2700 fps | 95.5% |
| IMR 4451 Enduron | <<locked>> | 84% | 42,714 psi | 67% | 2654 fps | 95.6% |
| IMR 4831 | <<locked>> | 82% | 32,532 psi | 51% | 2493 fps | 95.5% |
| IMR 4895 | <<locked>> | 80% | 44,498 psi | 70% | 2736 fps | 99.5% |
| IMR 8208 XBR | <<locked>> | 80% | 49,864 psi | 78% | 2769 fps | 100% |
| Lovex D073.6 | <<locked>> | 80% | 47,311 psi | 74% | 2743 fps | 100% |
| Lovex S060 | <<locked>> | 80% | 47,427 psi | 74% | 2700 fps | 99.7% |
| Lovex S062 | <<locked>> | 80% | 42,714 psi | 67% | 2654 fps | 99.8% |
| Lovex S065 | <<locked>> | 82% | 37,420 psi | 59% | 2546 fps | 95.6% |
| Lovex S070 | <<locked>> | 86% | 40,263 psi | 63% | 2628 fps | 95.3% |
| Norma 201 | <<locked>> | 80% | 46,818 psi | 73% | 2717 fps | 100% |
| Norma 202 | <<locked>> | 80% | 47,210 psi | 74% | 2720 fps | 100% |
| Norma 203B | <<locked>> | 80% | 42,830 psi | 67% | 2694 fps | 99.3% |
| Norma 204 | <<locked>> | 94% | 49,995 psi | 78% | 2848 fps | 95.6% |
| Norma MRP | <<locked>> | 96% | 41,655 psi | 65% | 2789 fps | 95.2% |
| Norma URP | <<locked>> | 82% | 33,678 psi | 53% | 2533 fps | 95.7% |
| Ramshot Big Game | <<locked>> | 80% | 42,598 psi | 67% | 2710 fps | 99.1% |
| Ramshot Hunter | <<locked>> | 86% | 37,623 psi | 59% | 2635 fps | 95.1% |
| Ramshot TAC | <<locked>> | 80% | 49,879 psi | 78% | 2785 fps | 98.7% |
| Ramshot Wild Boar | <<locked>> | 80% | 49,516 psi | 78% | 2802 fps | 99.8% |
| Ramshot X-Terminator | <<locked>> | 80% | 53,766 psi | 84% | 2822 fps | 100% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,064 psi | 42% | 1621 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 41,452 psi | 65% | 2635 fps | 96.1% |
| ReloadSwiss RS 52 | <<locked>> | 80% | 46,195 psi | 72% | 2815 fps | 99.4% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 37,362 psi | 59% | 2680 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 82% | 33,141 psi | 52% | 2549 fps | 95.3% |
| ReloadSwiss RS 70 | 41.1 gr | 84% | 35,476 psi | 56% | 2615 fps | 95.3% |
| Rottweil R 901 | <<locked>> | 80% | 50,981 psi | 80% | 2753 fps | 100% |
| Rottweil R 902 | <<locked>> | 80% | 44,628 psi | 70% | 2667 fps | 99.9% |
| Rottweil R 903 | <<locked>> | 80% | 38,000 psi | 60% | 2592 fps | 98.9% |
| Rottweil R 905 | <<locked>> | 98% | 46,876 psi | 73% | 2818 fps | 95.3% |
| Rottweil R 907 | <<locked>> | 86% | 43,656 psi | 68% | 2671 fps | 95.4% |
| Shooters World Long Rifle | <<locked>> | 82% | 37,420 psi | 59% | 2546 fps | 95.6% |
| Shooters World Match Rifle | <<locked>> | 80% | 47,311 psi | 74% | 2743 fps | 100% |
| Shooters World Precision | <<locked>> | 80% | 42,714 psi | 67% | 2654 fps | 99.8% |
| Shooters World SW4350 | <<locked>> | 86% | 40,263 psi | 63% | 2628 fps | 95.3% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 38,972 psi | 61% | 2641 fps | 98.5% |
| SNPE Vectan SP 7 | <<locked>> | 80% | 48,414 psi | 76% | 2759 fps | 98.9% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 46,296 psi | 73% | 2736 fps | 99.6% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 47,950 psi | 75% | 2661 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 40,132 psi | 63% | 2526 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 86% | 41,989 psi | 66% | 2602 fps | 95.6% |
| SNPE Vectan Tubal 8000 | <<locked>> | 98% | 46,427 psi | 73% | 2812 fps | 95.2% |
| Somchem S335 | <<locked>> | 80% | 47,616 psi | 75% | 2661 fps | 100% |
| Somchem S341 | <<locked>> | 80% | 48,066 psi | 75% | 2753 fps | 99.7% |
| Somchem S355 | <<locked>> | 80% | 38,711 psi | 61% | 2595 fps | 98.9% |
| Somchem S365 | <<locked>> | 80% | 28,297 psi | 44% | 2431 fps | 97.1% |
| Somchem S385 | <<locked>> | 96% | 44,628 psi | 70% | 2746 fps | 95.6% |
| Vihtavuori N130 | <<locked>> | 80% | 53,925 psi | 85% | 2713 fps | 100% |
| Vihtavuori N133 | <<locked>> | 80% | 48,370 psi | 76% | 2651 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 44,280 psi | 69% | 2641 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 44,715 psi | 70% | 2654 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 36,854 psi | 58% | 2530 fps | 99.4% |
| Vihtavuori N160 | <<locked>> | 80% | 32,895 psi | 52% | 2484 fps | 95.3% |
| Vihtavuori N530 | <<locked>> | 80% | 50,082 psi | 78% | 2769 fps | 100% |
| Vihtavuori N540 | <<locked>> | 80% | 43,149 psi | 68% | 2644 fps | 100% |
| Vihtavuori N550 | <<locked>> | 82% | 34,563 psi | 54% | 2536 fps | 95.8% |
| Vihtavuori N555 | <<locked>> | 88% | 31,691 psi | 50% | 2533 fps | 95.9% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 32,561 psi | 51% | 2457 fps | 97.6% |
| Winchester 748 | <<locked>> | 80% | 50,067 psi | 78% | 2815 fps | 100% |
| Winchester 760 | <<locked>> | 86% | 40,959 psi | 64% | 2700 fps | 95.3% |
| Winchester StaBALL HD | <<locked>> | 90% | 27,470 psi | 43% | 2470 fps | 95.1% |
| Winchester StaBALL Match | <<locked>> | 80% | 45,919 psi | 72% | 2743 fps | 99.8% |
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 102 powders for .25 WSSM loaded with the .257 | 117gr | Winchester SPRN. ReloadSwiss RS 70 delivers the highest muzzle velocity at 3,045 fps; across all powders the maximum-charge window runs from 1,775 fps to 3,045 fps. Accurate 3100 gives the best case fill at 100 %, and 102 of the 102 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 117.0 gr projectile in 0.257" calls for a 1:12.5 twist; slower twists will usually not stabilise this weight. Accurate 3100, ADI AR 2209, Alliant Power Pro Varmint 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. ReloadSwiss RS 70, Hodgdon Superformance, Alliant Reloder-17 rank at the top here: for .25 WSSM with the .257 | 117gr | Winchester SPRN 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.