Load Specifications
Bullet Manufacturer:Sierra
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:1:11.5
Load data in caliber .25 WSSM with .257 | 117gr | Sierra SPT Pro-Hunter bullet and 101 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Alliant Reloder-17, ReloadSwiss RS 60 and Winchester 760.
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>> | 84% | 57,638 psi | 90% | 2792 fps | 100% |
| Accurate 2495 | <<locked>> | 88% | 56,840 psi | 89% | 2825 fps | 100% |
| Accurate 2520 | <<locked>> | 82% | 54,462 psi | 85% | 2835 fps | 100% |
| Accurate 2700 | <<locked>> | 88% | 55,622 psi | 87% | 2831 fps | 97.6% |
| Accurate 3100ᴾ | <<locked>> | 100% | 43,555 psi | 68% | 2726 fps | 97% |
| Accurate 4064 | <<locked>> | 90% | 56,913 psi | 89% | 2874 fps | 100% |
| Accurate 4350 | <<locked>> | 98% | 56,666 psi | 89% | 2963 fps | 99.9% |
| ADI AR 2206H | <<locked>> | 86% | 56,608 psi | 89% | 2904 fps | 100% |
| ADI AR 2208 | <<locked>> | 92% | 57,711 psi | 90% | 2904 fps | 100% |
| ADI AR 2209ᴾ | <<locked>> | 100% | 51,416 psi | 81% | 2884 fps | 95.9% |
| ADI Benchmark 8208 | <<locked>> | 84% | 55,506 psi | 87% | 2851 fps | 100% |
| Alliant AR-Comp | <<locked>> | 84% | 56,855 psi | 89% | 2822 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 88% | 56,623 psi | 89% | 3028 fps | 100% |
| Alliant Power Pro Varmintᴾ | <<locked>> | 100% | 50,952 psi | 80% | 2877 fps | 95.9% |
| Alliant Reloder- TS 15.5 | <<locked>> | 90% | 54,665 psi | 86% | 2877 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 88% | 54,897 psi | 86% | 2897 fps | 99.9% |
| Alliant Reloder-16 | <<locked>> | 98% | 54,273 psi | 85% | 2969 fps | 99.9% |
| Alliant Reloder-17 | <<locked>> | 94% | 55,419 psi | 87% | 3002 fps | 100% |
| Alliant Reloder-19ᴾ | <<locked>> | 100% | 50,198 psi | 79% | 2871 fps | 95.8% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 41,597 psi | 65% | 2759 fps | 99.5% |
| Alliant Reloder-26ᴾ | <<locked>> | 100% | 46,615 psi | 73% | 2927 fps | 99% |
| Baschieri & Pellagri 107 | <<locked>> | 86% | 56,753 psi | 89% | 2923 fps | 99.9% |
| Bofors RP3 | <<locked>> | 90% | 55,317 psi | 87% | 2894 fps | 100% |
| Bofors RP7 | <<locked>> | 94% | 55,259 psi | 87% | 2867 fps | 97.8% |
| Hodgdon Benchmark | <<locked>> | 84% | 57,392 psi | 90% | 2835 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 84% | 55,187 psi | 86% | 2884 fps | 100% |
| Hodgdon CFE223 | <<locked>> | 82% | 57,479 psi | 90% | 2989 fps | 100% |
| Hodgdon H380 | <<locked>> | 90% | 55,999 psi | 88% | 2907 fps | 99.7% |
| Hodgdon H414 | <<locked>> | 96% | 55,956 psi | 88% | 2963 fps | 98.5% |
| Hodgdon H4350 | <<locked>> | 94% | 56,289 psi | 88% | 2923 fps | 97.4% |
| Hodgdon H4895 | <<locked>> | 86% | 57,188 psi | 90% | 2910 fps | 100% |
| Hodgdon Hybrid 100Vᴾ | <<locked>> | 100% | 54,186 psi | 85% | 2894 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 88% | 57,072 psi | 89% | 2949 fps | 100% |
| Hodgdon Superformance | <<locked>> | 96% | 56,275 psi | 88% | 2999 fps | 98.2% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 35,795 psi | 56% | 1765 fps | 100% |
| Hodgdon VARGET | <<locked>> | 86% | 54,998 psi | 86% | 2864 fps | 100% |
| IMR 3031 | <<locked>> | 86% | 57,464 psi | 90% | 2890 fps | 100% |
| IMR 4064 | <<locked>> | 90% | 57,493 psi | 90% | 2890 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 88% | 56,985 psi | 89% | 2867 fps | 98.5% |
| IMR 4350 | <<locked>> | 98% | 55,506 psi | 87% | 2890 fps | 97.9% |
| IMR 4451 Enduron | <<locked>> | 94% | 56,811 psi | 89% | 2894 fps | 98.4% |
| IMR 4831ᴾ | <<locked>> | 100% | 57,479 psi | 90% | 2956 fps | 99.9% |
| IMR 4895 | <<locked>> | 88% | 56,318 psi | 88% | 2927 fps | 100% |
| IMR 8208 XBR | <<locked>> | 84% | 55,506 psi | 87% | 2851 fps | 100% |
| Lovex D073.6 | <<locked>> | 86% | 56,753 psi | 89% | 2877 fps | 100% |
| Lovex S060 | <<locked>> | 86% | 56,115 psi | 88% | 2831 fps | 100% |
| Lovex S062 | <<locked>> | 90% | 57,058 psi | 89% | 2881 fps | 100% |
| Lovex S065 | <<locked>> | 96% | 56,492 psi | 89% | 2890 fps | 99.3% |
| Lovex S070 | <<locked>> | 98% | 57,667 psi | 90% | 2927 fps | 98.8% |
| Norma 201 | <<locked>> | 86% | 55,506 psi | 87% | 2848 fps | 100% |
| Norma 202 | <<locked>> | 86% | 56,043 psi | 88% | 2848 fps | 100% |
| Norma 203B | <<locked>> | 90% | 57,609 psi | 90% | 2933 fps | 100% |
| Norma 204 | <<locked>> | 98% | 56,289 psi | 88% | 2943 fps | 96.8% |
| Norma MRPᴾ | <<locked>> | 100% | 46,441 psi | 73% | 2881 fps | 96.5% |
| Norma URP | <<locked>> | 98% | 55,825 psi | 87% | 2953 fps | 99.8% |
| Ramshot Big Game | <<locked>> | 88% | 54,737 psi | 86% | 2910 fps | 100% |
| Ramshot Hunter | <<locked>> | 98% | 54,505 psi | 85% | 2949 fps | 98.9% |
| Ramshot TAC | <<locked>> | 84% | 55,883 psi | 88% | 2874 fps | 99.3% |
| Ramshot Wild Boar | <<locked>> | 84% | 55,535 psi | 87% | 2890 fps | 100% |
| Ramshot X-Terminator | <<locked>> | 82% | 56,318 psi | 88% | 2854 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 36,347 psi | 57% | 1804 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 90% | 56,376 psi | 88% | 2890 fps | 98.9% |
| ReloadSwiss RS 52 | <<locked>> | 86% | 55,622 psi | 87% | 2966 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 92% | 55,303 psi | 87% | 3002 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 98% | 56,782 psi | 89% | 2989 fps | 99.8% |
| ReloadSwiss RS 70 | <<locked>> | 98% | 55,767 psi | 87% | 3015 fps | 99.7% |
| Rottweil R 901 | <<locked>> | 84% | 56,260 psi | 88% | 2825 fps | 100% |
| Rottweil R 902 | <<locked>> | 88% | 55,970 psi | 88% | 2848 fps | 100% |
| Rottweil R 903 | <<locked>> | 92% | 55,143 psi | 86% | 2884 fps | 100% |
| Rottweil R 907 | <<locked>> | 94% | 55,259 psi | 87% | 2867 fps | 97.8% |
| Shooters World Long Rifle | <<locked>> | 96% | 56,492 psi | 89% | 2890 fps | 99.3% |
| Shooters World Match Rifle | <<locked>> | 86% | 56,753 psi | 89% | 2877 fps | 100% |
| Shooters World Precision | <<locked>> | 90% | 57,058 psi | 89% | 2881 fps | 100% |
| Shooters World SW4350 | <<locked>> | 98% | 57,667 psi | 90% | 2927 fps | 98.8% |
| SNPE Vectan SP 11 | <<locked>> | 92% | 56,884 psi | 89% | 2946 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 84% | 54,447 psi | 85% | 2854 fps | 99.5% |
| SNPE Vectan SP 9 | <<locked>> | 86% | 55,187 psi | 86% | 2877 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 86% | 56,681 psi | 89% | 2782 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 92% | 57,246 psi | 90% | 2782 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 96% | 56,637 psi | 89% | 2841 fps | 98.4% |
| Somchem S321 | <<locked>> | 82% | 56,768 psi | 89% | 2881 fps | 100% |
| Somchem S335 | <<locked>> | 86% | 56,275 psi | 88% | 2779 fps | 100% |
| Somchem S341 | <<locked>> | 84% | 53,969 psi | 85% | 2841 fps | 100% |
| Somchem S355 | <<locked>> | 92% | 55,172 psi | 86% | 2881 fps | 100% |
| Somchem S365ᴾ | <<locked>> | 100% | 53,795 psi | 84% | 2949 fps | 100% |
| Somchem S385ᴾ | <<locked>> | 100% | 49,763 psi | 78% | 2831 fps | 96.8% |
| Vihtavuori N130 | <<locked>> | 82% | 56,362 psi | 88% | 2740 fps | 100% |
| Vihtavuori N133 | <<locked>> | 86% | 56,985 psi | 89% | 2762 fps | 100% |
| Vihtavuori N135 | <<locked>> | 88% | 56,014 psi | 88% | 2808 fps | 100% |
| Vihtavuori N140 | <<locked>> | 88% | 56,608 psi | 89% | 2825 fps | 100% |
| Vihtavuori N150 | <<locked>> | 94% | 56,869 psi | 89% | 2858 fps | 100% |
| Vihtavuori N160 | <<locked>> | 96% | 54,433 psi | 85% | 2890 fps | 99.7% |
| Vihtavuori N530 | <<locked>> | 84% | 55,956 psi | 88% | 2848 fps | 100% |
| Vihtavuori N540 | <<locked>> | 88% | 54,795 psi | 86% | 2822 fps | 100% |
| Vihtavuori N550 | <<locked>> | 98% | 57,232 psi | 90% | 2953 fps | 99.8% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 46,006 psi | 72% | 2838 fps | 99.4% |
| Winchester 6.5 StaBALL | <<locked>> | 96% | 54,549 psi | 85% | 2867 fps | 100% |
| Winchester 748 | <<locked>> | 84% | 56,318 psi | 88% | 2900 fps | 100% |
| Winchester 760 | <<locked>> | 96% | 55,956 psi | 88% | 2963 fps | 98.5% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 37,217 psi | 58% | 2776 fps | 99.6% |
| Winchester StaBALL Match | <<locked>> | 86% | 54,969 psi | 86% | 2881 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% | 51,068 psi | 80% | 2703 fps | 100% |
| Accurate 2495 | <<locked>> | 80% | 43,947 psi | 69% | 2635 fps | 100% |
| Accurate 2520 | <<locked>> | 80% | 51,053 psi | 80% | 2785 fps | 100% |
| Accurate 2700 | <<locked>> | 82% | 45,455 psi | 71% | 2657 fps | 95.4% |
| Accurate 3100 | <<locked>> | 96% | 37,956 psi | 59% | 2615 fps | 95.3% |
| Accurate 4064 | <<locked>> | 80% | 41,539 psi | 65% | 2635 fps | 100% |
| Accurate 4350 | <<locked>> | 82% | 32,648 psi | 51% | 2510 fps | 95.4% |
| ADI AR 2206H | <<locked>> | 80% | 46,920 psi | 74% | 2746 fps | 99.6% |
| ADI AR 2208 | <<locked>> | 80% | 40,030 psi | 63% | 2598 fps | 98.2% |
| ADI AR 2209 | <<locked>> | 98% | 48,211 psi | 76% | 2825 fps | 95% |
| ADI Benchmark 8208 | <<locked>> | 80% | 48,965 psi | 77% | 2749 fps | 100% |
| Alliant AR-Comp | <<locked>> | 80% | 50,053 psi | 78% | 2733 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 43,033 psi | 67% | 2789 fps | 98.8% |
| Alliant Power Pro Varmint | <<locked>> | 98% | 47,776 psi | 75% | 2822 fps | 95.1% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 39,668 psi | 62% | 2618 fps | 99.3% |
| Alliant Reloder-15 | <<locked>> | 80% | 42,598 psi | 67% | 2684 fps | 98.8% |
| Alliant Reloder-16 | <<locked>> | 82% | 32,982 psi | 52% | 2526 fps | 95.5% |
| Alliant Reloder-17 | 37.8 gr | 80% | 34,461 psi | 54% | 2595 fps | 97.9% |
| Alliant Reloder-19 | <<locked>> | 98% | 47,094 psi | 74% | 2812 fps | 95% |
| Alliant Reloder-23 | <<locked>> | 88% | 28,660 psi | 45% | 2431 fps | 95.2% |
| Alliant Reloder-26 | <<locked>> | 92% | 35,070 psi | 55% | 2664 fps | 95.6% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 46,456 psi | 73% | 2753 fps | 99% |
| Bofors RP3 | <<locked>> | 80% | 39,523 psi | 62% | 2625 fps | 99.3% |
| Bofors RP7 | <<locked>> | 86% | 42,946 psi | 67% | 2648 fps | 95% |
| Hodgdon Benchmark | <<locked>> | 80% | 50,734 psi | 80% | 2736 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 80% | 48,327 psi | 76% | 2776 fps | 100% |
| Hodgdon CFE223 | <<locked>> | 80% | 53,505 psi | 84% | 2930 fps | 99.9% |
| Hodgdon H380 | <<locked>> | 80% | 40,277 psi | 63% | 2628 fps | 97.3% |
| Hodgdon H414 | <<locked>> | 88% | 42,931 psi | 67% | 2733 fps | 95.8% |
| Hodgdon H4350 | <<locked>> | 88% | 46,615 psi | 73% | 2756 fps | 95.2% |
| Hodgdon H4895 | <<locked>> | 80% | 47,355 psi | 74% | 2756 fps | 99.9% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 28,456 psi | 45% | 2372 fps | 95.5% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 43,497 psi | 68% | 2730 fps | 99.8% |
| Hodgdon Superformance | <<locked>> | 90% | 45,368 psi | 71% | 2808 fps | 95.9% |
| Hodgdon TrailBoss | <<locked>> | 80% | 26,513 psi | 42% | 1572 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 45,455 psi | 71% | 2707 fps | 99.7% |
| IMR 3031 | <<locked>> | 80% | 47,340 psi | 74% | 2746 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 42,061 psi | 66% | 2631 fps | 98.8% |
| IMR 4166 Enduron | <<locked>> | 80% | 44,469 psi | 70% | 2651 fps | 96% |
| IMR 4350 | <<locked>> | 90% | 43,192 psi | 68% | 2677 fps | 95.1% |
| IMR 4451 Enduron | <<locked>> | 84% | 42,003 psi | 66% | 2631 fps | 95.2% |
| IMR 4831 | <<locked>> | 82% | 31,778 psi | 50% | 2470 fps | 95.1% |
| IMR 4895 | <<locked>> | 80% | 43,627 psi | 68% | 2710 fps | 99.3% |
| IMR 8208 XBR | <<locked>> | 80% | 48,965 psi | 77% | 2749 fps | 100% |
| Lovex D073.6 | <<locked>> | 80% | 46,383 psi | 73% | 2723 fps | 100% |
| Lovex S060 | <<locked>> | 80% | 46,905 psi | 74% | 2684 fps | 99.6% |
| Lovex S062 | <<locked>> | 80% | 42,163 psi | 66% | 2638 fps | 99.7% |
| Lovex S065 | <<locked>> | 82% | 36,680 psi | 57% | 2523 fps | 95.2% |
| Lovex S070 | <<locked>> | 88% | 42,105 psi | 66% | 2657 fps | 95.7% |
| Norma 201 | <<locked>> | 80% | 46,209 psi | 72% | 2700 fps | 100% |
| Norma 202 | <<locked>> | 80% | 46,311 psi | 73% | 2700 fps | 100% |
| Norma 203B | <<locked>> | 80% | 41,959 psi | 66% | 2671 fps | 99.1% |
| Norma 204 | <<locked>> | 94% | 49,023 psi | 77% | 2825 fps | 95.2% |
| Norma MRP | <<locked>> | 98% | 43,555 psi | 68% | 2825 fps | 95.7% |
| Norma URP | <<locked>> | 82% | 32,938 psi | 52% | 2510 fps | 95.3% |
| Ramshot Big Game | <<locked>> | 80% | 41,800 psi | 66% | 2687 fps | 98.9% |
| Ramshot Hunter | <<locked>> | 88% | 39,117 psi | 61% | 2661 fps | 95.5% |
| Ramshot TAC | <<locked>> | 80% | 49,168 psi | 77% | 2766 fps | 98.5% |
| Ramshot Wild Boar | <<locked>> | 80% | 48,689 psi | 76% | 2782 fps | 99.8% |
| Ramshot X-Terminator | <<locked>> | 80% | 53,026 psi | 83% | 2802 fps | 99.9% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,079 psi | 42% | 1614 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 40,698 psi | 64% | 2612 fps | 95.7% |
| ReloadSwiss RS 52 | <<locked>> | 80% | 45,252 psi | 71% | 2792 fps | 99.2% |
| ReloadSwiss RS 60 | 37.8 gr | 80% | 36,651 psi | 57% | 2661 fps | 99.9% |
| ReloadSwiss RS 62 | <<locked>> | 84% | 34,650 psi | 54% | 2582 fps | 95.7% |
| ReloadSwiss RS 70 | <<locked>> | 86% | 37,188 psi | 58% | 2651 fps | 95.9% |
| Rottweil R 901 | <<locked>> | 80% | 49,995 psi | 78% | 2730 fps | 100% |
| Rottweil R 902 | <<locked>> | 80% | 43,729 psi | 69% | 2648 fps | 99.8% |
| Rottweil R 903 | <<locked>> | 80% | 37,159 psi | 58% | 2566 fps | 98.7% |
| Rottweil R 907 | <<locked>> | 86% | 42,946 psi | 67% | 2648 fps | 95% |
| Shooters World Long Rifle | <<locked>> | 82% | 36,680 psi | 57% | 2523 fps | 95.2% |
| Shooters World Match Rifle | <<locked>> | 80% | 46,383 psi | 73% | 2723 fps | 100% |
| Shooters World Precision | <<locked>> | 80% | 42,163 psi | 66% | 2638 fps | 99.7% |
| Shooters World SW4350 | <<locked>> | 88% | 42,105 psi | 66% | 2657 fps | 95.7% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 38,174 psi | 60% | 2618 fps | 98.3% |
| SNPE Vectan SP 7 | <<locked>> | 80% | 47,616 psi | 75% | 2740 fps | 98.6% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 45,469 psi | 71% | 2717 fps | 99.5% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 47,340 psi | 74% | 2644 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 39,566 psi | 62% | 2513 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 86% | 40,973 psi | 64% | 2572 fps | 95.1% |
| Somchem S321 | <<locked>> | 80% | 53,359 psi | 84% | 2831 fps | 100% |
| Somchem S335 | <<locked>> | 80% | 47,094 psi | 74% | 2648 fps | 100% |
| Somchem S341 | <<locked>> | 80% | 47,297 psi | 74% | 2736 fps | 99.6% |
| Somchem S355 | <<locked>> | 80% | 38,145 psi | 60% | 2579 fps | 98.7% |
| Somchem S365 | <<locked>> | 80% | 27,644 psi | 43% | 2405 fps | 96.7% |
| Somchem S385 | <<locked>> | 96% | 43,700 psi | 68% | 2723 fps | 95.2% |
| Vihtavuori N130 | <<locked>> | 80% | 53,287 psi | 84% | 2697 fps | 100% |
| Vihtavuori N133 | <<locked>> | 80% | 47,718 psi | 75% | 2635 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 43,627 psi | 68% | 2628 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 43,874 psi | 69% | 2635 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 36,042 psi | 56% | 2507 fps | 99.2% |
| Vihtavuori N160 | <<locked>> | 82% | 34,374 psi | 54% | 2513 fps | 95.8% |
| Vihtavuori N530 | <<locked>> | 80% | 49,182 psi | 77% | 2746 fps | 100% |
| Vihtavuori N540 | <<locked>> | 80% | 42,380 psi | 66% | 2625 fps | 100% |
| Vihtavuori N550 | <<locked>> | 82% | 33,866 psi | 53% | 2513 fps | 95.4% |
| Vihtavuori N555 | <<locked>> | 88% | 30,951 psi | 49% | 2510 fps | 95.4% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 32,039 psi | 50% | 2438 fps | 97.2% |
| Winchester 748 | <<locked>> | 80% | 49,168 psi | 77% | 2795 fps | 100% |
| Winchester 760 | 40.7 gr | 88% | 42,931 psi | 67% | 2733 fps | 95.8% |
| Winchester StaBALL HD | <<locked>> | 92% | 28,776 psi | 45% | 2510 fps | 95.9% |
| Winchester StaBALL Match | <<locked>> | 80% | 45,136 psi | 71% | 2723 fps | 99.7% |
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 101 powders for .25 WSSM loaded with the .257 | 117gr | Sierra SPT Pro-Hunter. Alliant Power Pro 2000-MR delivers the highest muzzle velocity at 3,028 fps; across all powders the maximum-charge window runs from 1,765 fps to 3,028 fps. Accurate 3100 gives the best case fill at 100 %, and 101 of the 101 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 1:11.5 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. Alliant Reloder-17, ReloadSwiss RS 60, Winchester 760 rank at the top here: for .25 WSSM with the .257 | 117gr | Sierra SPT Pro-Hunter 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.