Load Specifications
Load data in caliber .25 WSSM with .257 | 87gr | Speer MHP 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 Power Pro 2000-MR, ReloadSwiss RS 52 and ReloadSwiss RS 60.
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: 24"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2015 | <<locked>> | 88% | 54,795 psi | 86% | 3189 fps | 100% |
| Accurate 2460 | <<locked>> | 86% | 57,203 psi | 90% | 3268 fps | 100% |
| Accurate 2495 | <<locked>> | 94% | 56,420 psi | 88% | 3258 fps | 100% |
| Accurate 2520 | <<locked>> | 88% | 55,361 psi | 87% | 3278 fps | 100% |
| Accurate 4064 | <<locked>> | 96% | 55,970 psi | 88% | 3297 fps | 100% |
| Accurate 4350ᴾ | <<locked>> | 100% | 48,472 psi | 76% | 3228 fps | 96.8% |
| Accurate LT-30 | <<locked>> | 84% | 57,696 psi | 90% | 3186 fps | 100% |
| Accurate LT-32 | <<locked>> | 82% | 54,665 psi | 86% | 3159 fps | 100% |
| ADI AR 2206H | <<locked>> | 92% | 57,595 psi | 90% | 3337 fps | 99.3% |
| ADI AR 2208 | <<locked>> | 96% | 55,230 psi | 87% | 3271 fps | 98.5% |
| ADI AR 2219 | <<locked>> | 82% | 55,288 psi | 87% | 3264 fps | 100% |
| ADI Benchmark 8208 | <<locked>> | 90% | 56,869 psi | 89% | 3291 fps | 99.7% |
| Alliant AR-Comp | <<locked>> | 90% | 56,768 psi | 89% | 3278 fps | 100% |
| Alliant Power Pro 1200-R | <<locked>> | 84% | 54,839 psi | 86% | 3356 fps | 99.3% |
| Alliant Power Pro 2000-MR | <<locked>> | 94% | 57,363 psi | 90% | 3455 fps | 98.8% |
| Alliant Reloder- TS 15.5 | <<locked>> | 96% | 54,331 psi | 85% | 3291 fps | 99.4% |
| Alliant Reloder-10x | <<locked>> | 84% | 54,491 psi | 85% | 3205 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 94% | 55,201 psi | 87% | 3314 fps | 98.7% |
| Alliant Reloder-16ᴾ | <<locked>> | 100% | 47,471 psi | 74% | 3228 fps | 96.7% |
| Alliant Reloder-17ᴾ | <<locked>> | 100% | 55,274 psi | 87% | 3409 fps | 99.5% |
| Baschieri & Pellagri 106 | <<locked>> | 84% | 57,406 psi | 90% | 3179 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 90% | 54,012 psi | 85% | 3284 fps | 98% |
| Bofors RP3 | <<locked>> | 96% | 55,187 psi | 86% | 3310 fps | 99.6% |
| Hodgdon Benchmark | <<locked>> | 88% | 55,347 psi | 87% | 3222 fps | 99.8% |
| Hodgdon BL-C2 | <<locked>> | 90% | 55,941 psi | 88% | 3317 fps | 99.9% |
| Hodgdon CFE223 | <<locked>> | 86% | 53,795 psi | 84% | 3356 fps | 98.5% |
| Hodgdon H322 | <<locked>> | 86% | 57,682 psi | 90% | 3304 fps | 100% |
| Hodgdon H335 | <<locked>> | 84% | 55,259 psi | 87% | 3268 fps | 100% |
| Hodgdon H380 | <<locked>> | 96% | 56,753 psi | 89% | 3320 fps | 97.8% |
| Hodgdon H4895 | <<locked>> | 90% | 54,694 psi | 86% | 3294 fps | 99.3% |
| Hodgdon Hybrid 100Vᴾ | <<locked>> | 100% | 43,642 psi | 68% | 3097 fps | 97.4% |
| Hodgdon LEVERevolution | <<locked>> | 94% | 57,217 psi | 90% | 3379 fps | 99.7% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 34,679 psi | 54% | 2037 fps | 100% |
| Hodgdon VARGET | <<locked>> | 92% | 56,159 psi | 88% | 3297 fps | 99.4% |
| IMR 3031 | <<locked>> | 92% | 57,624 psi | 90% | 3346 fps | 100% |
| IMR 4064 | <<locked>> | 94% | 54,708 psi | 86% | 3255 fps | 98.6% |
| IMR 4198 | <<locked>> | 84% | 54,824 psi | 86% | 3166 fps | 100% |
| IMR 4831ᴾ | <<locked>> | 100% | 45,832 psi | 72% | 3156 fps | 96.3% |
| IMR 4895 | <<locked>> | 94% | 56,565 psi | 89% | 3353 fps | 99.2% |
| IMR 8208 XBR | <<locked>> | 90% | 56,869 psi | 89% | 3291 fps | 99.7% |
| Lovex D073.5 | <<locked>> | 86% | 57,145 psi | 90% | 3278 fps | 100% |
| Lovex D073.6 | <<locked>> | 92% | 56,985 psi | 89% | 3314 fps | 100% |
| Lovex S060 | <<locked>> | 92% | 57,421 psi | 90% | 3258 fps | 99.2% |
| Lovex S062 | <<locked>> | 96% | 57,696 psi | 90% | 3310 fps | 99.8% |
| Lovex S065ᴾ | <<locked>> | 100% | 53,142 psi | 83% | 3222 fps | 96.3% |
| Norma 201 | <<locked>> | 92% | 56,347 psi | 88% | 3281 fps | 99.7% |
| Norma 202 | <<locked>> | 92% | 56,681 psi | 89% | 3287 fps | 100% |
| Norma 203B | <<locked>> | 94% | 54,273 psi | 85% | 3301 fps | 98.9% |
| Norma URPᴾ | <<locked>> | 100% | 47,863 psi | 75% | 3215 fps | 96.6% |
| Ramshot Big Game | <<locked>> | 94% | 55,013 psi | 86% | 3323 fps | 98.9% |
| Ramshot TAC | <<locked>> | 88% | 54,099 psi | 85% | 3238 fps | 96.7% |
| Ramshot Wild Boar | <<locked>> | 90% | 56,942 psi | 89% | 3323 fps | 99.2% |
| Ramshot X-Terminator | <<locked>> | 86% | 54,578 psi | 86% | 3228 fps | 98.8% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 34,983 psi | 55% | 2083 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 86% | 56,492 psi | 89% | 3281 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 96% | 57,232 psi | 90% | 3294 fps | 96.4% |
| ReloadSwiss RS 52 | <<locked>> | 92% | 55,361 psi | 87% | 3386 fps | 98.6% |
| ReloadSwiss RS 60 | <<locked>> | 98% | 55,419 psi | 87% | 3428 fps | 100% |
| ReloadSwiss RS 62ᴾ | <<locked>> | 100% | 48,109 psi | 75% | 3245 fps | 96.4% |
| Rottweil R 901 | <<locked>> | 90% | 57,276 psi | 90% | 3271 fps | 100% |
| Rottweil R 902 | <<locked>> | 94% | 56,768 psi | 89% | 3274 fps | 99.7% |
| Rottweil R 903 | <<locked>> | 98% | 54,665 psi | 86% | 3294 fps | 99.4% |
| Shooters World Long Rifleᴾ | <<locked>> | 100% | 53,142 psi | 83% | 3222 fps | 96.3% |
| Shooters World Match Rifle | <<locked>> | 92% | 56,985 psi | 89% | 3314 fps | 100% |
| Shooters World Precision | <<locked>> | 96% | 57,696 psi | 90% | 3310 fps | 99.8% |
| Shooters World Tactical Rifle | <<locked>> | 84% | 56,318 psi | 88% | 3238 fps | 99.6% |
| SNPE Vectan BA6 1/2 | <<locked>> | 82% | 57,319 psi | 90% | 2910 fps | 100% |
| SNPE Vectan SP 10 | <<locked>> | 82% | 55,782 psi | 87% | 3274 fps | 100% |
| SNPE Vectan SP 11 | <<locked>> | 98% | 56,782 psi | 89% | 3363 fps | 99.2% |
| SNPE Vectan SP 3 | <<locked>> | 84% | 55,448 psi | 87% | 3228 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 90% | 55,535 psi | 87% | 3268 fps | 97.5% |
| SNPE Vectan SP 9 | <<locked>> | 92% | 56,014 psi | 88% | 3301 fps | 99.1% |
| SNPE Vectan Tubal 3000 | <<locked>> | 90% | 54,868 psi | 86% | 3173 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 96% | 54,491 psi | 85% | 3163 fps | 100% |
| Somchem S321 | <<locked>> | 86% | 54,795 psi | 86% | 3271 fps | 99.7% |
| Somchem S335 | <<locked>> | 92% | 57,435 psi | 90% | 3222 fps | 100% |
| Somchem S341 | <<locked>> | 90% | 55,187 psi | 86% | 3264 fps | 98.9% |
| Somchem S355 | <<locked>> | 98% | 55,172 psi | 86% | 3294 fps | 99.3% |
| Somchem S365ᴾ | <<locked>> | 100% | 42,772 psi | 67% | 3156 fps | 98.6% |
| Vihtavuori N130 | <<locked>> | 86% | 54,476 psi | 85% | 3146 fps | 100% |
| Vihtavuori N133 | <<locked>> | 90% | 54,839 psi | 86% | 3163 fps | 100% |
| Vihtavuori N135 | <<locked>> | 94% | 55,506 psi | 87% | 3245 fps | 100% |
| Vihtavuori N140 | <<locked>> | 94% | 57,377 psi | 90% | 3264 fps | 100% |
| Vihtavuori N150ᴾ | <<locked>> | 100% | 56,869 psi | 89% | 3274 fps | 99.9% |
| Vihtavuori N160ᴾ | <<locked>> | 100% | 50,778 psi | 80% | 3225 fps | 97.1% |
| Vihtavuori N530 | <<locked>> | 90% | 57,421 psi | 90% | 3291 fps | 99.8% |
| Vihtavuori N540 | <<locked>> | 94% | 55,535 psi | 87% | 3251 fps | 100% |
| Vihtavuori N550ᴾ | <<locked>> | 100% | 49,879 psi | 78% | 3225 fps | 96.8% |
| Winchester 6.5 StaBALLᴾ | <<locked>> | 100% | 51,909 psi | 81% | 3209 fps | 99.1% |
| Winchester 748 | <<locked>> | 90% | 56,826 psi | 89% | 3340 fps | 100% |
| Winchester StaBALL Match | <<locked>> | 92% | 55,695 psi | 87% | 3304 fps | 99.4% |
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% | 42,873 psi | 67% | 2982 fps | 100% |
| Accurate 2460 | <<locked>> | 80% | 46,789 psi | 73% | 3094 fps | 99.8% |
| Accurate 2495 | <<locked>> | 80% | 35,360 psi | 55% | 2867 fps | 99.9% |
| Accurate 2520 | <<locked>> | 80% | 41,771 psi | 65% | 3028 fps | 99.1% |
| Accurate 4064 | <<locked>> | 80% | 33,417 psi | 52% | 2838 fps | 98.1% |
| Accurate 4350 | <<locked>> | 96% | 41,916 psi | 66% | 3094 fps | 95% |
| Accurate LT-30 | <<locked>> | 80% | 51,039 psi | 80% | 3081 fps | 100% |
| Accurate LT-32 | <<locked>> | 80% | 51,416 psi | 81% | 3104 fps | 99.9% |
| ADI AR 2206H | <<locked>> | 80% | 39,349 psi | 62% | 2969 fps | 95.6% |
| ADI AR 2208 | <<locked>> | 86% | 40,379 psi | 63% | 2972 fps | 95.1% |
| ADI AR 2219 | <<locked>> | 80% | 51,532 psi | 81% | 3205 fps | 100% |
| ADI Benchmark 8208 | <<locked>> | 80% | 41,321 psi | 65% | 2992 fps | 97.5% |
| Alliant AR-Comp | <<locked>> | 80% | 40,567 psi | 64% | 3009 fps | 100% |
| Alliant Power Pro 1200-R | <<locked>> | 80% | 47,863 psi | 75% | 3222 fps | 98.3% |
| Alliant Power Pro 2000-MR | 42.9 gr | 86% | 43,526 psi | 68% | 3169 fps | 95.7% |
| Alliant Reloder- TS 15.5 | <<locked>> | 82% | 34,824 psi | 55% | 2874 fps | 95.2% |
| Alliant Reloder-10x | <<locked>> | 80% | 48,356 psi | 76% | 3104 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 84% | 40,234 psi | 63% | 3009 fps | 95.3% |
| Alliant Reloder-16 | <<locked>> | 96% | 42,003 psi | 66% | 3104 fps | 95% |
| Alliant Reloder-17 | <<locked>> | 88% | 36,767 psi | 58% | 2999 fps | 95% |
| Baschieri & Pellagri 106 | <<locked>> | 80% | 50,183 psi | 79% | 3064 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 84% | 44,106 psi | 69% | 3091 fps | 95.8% |
| Bofors RP3 | <<locked>> | 82% | 34,098 psi | 53% | 2867 fps | 95% |
| Hodgdon Benchmark | <<locked>> | 80% | 43,250 psi | 68% | 2992 fps | 98.5% |
| Hodgdon BL-C2 | <<locked>> | 80% | 39,566 psi | 62% | 2999 fps | 97.7% |
| Hodgdon CFE223 | <<locked>> | 80% | 43,584 psi | 68% | 3150 fps | 96.3% |
| Hodgdon H322 | <<locked>> | 80% | 46,978 psi | 74% | 3123 fps | 100% |
| Hodgdon H335 | <<locked>> | 80% | 48,196 psi | 76% | 3146 fps | 99.9% |
| Hodgdon H380 | <<locked>> | 90% | 46,311 psi | 73% | 3127 fps | 95.6% |
| Hodgdon H4895 | <<locked>> | 80% | 39,610 psi | 62% | 2986 fps | 96.4% |
| Hodgdon Hybrid 100V | <<locked>> | 96% | 38,406 psi | 60% | 2979 fps | 95.8% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 35,607 psi | 56% | 2933 fps | 95.5% |
| Hodgdon TrailBoss | <<locked>> | 80% | 25,614 psi | 40% | 1821 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 38,203 psi | 60% | 2933 fps | 95.9% |
| IMR 3031 | <<locked>> | 80% | 38,435 psi | 60% | 2995 fps | 99.8% |
| IMR 4064 | <<locked>> | 84% | 39,769 psi | 62% | 2953 fps | 95.2% |
| IMR 4198 | <<locked>> | 80% | 48,617 psi | 76% | 3068 fps | 100% |
| IMR 4831 | <<locked>> | 98% | 42,975 psi | 67% | 3097 fps | 95.5% |
| IMR 4895 | <<locked>> | 82% | 38,392 psi | 60% | 2979 fps | 95.4% |
| IMR 8208 XBR | <<locked>> | 80% | 41,321 psi | 65% | 2992 fps | 97.5% |
| Lovex D073.5 | <<locked>> | 80% | 46,441 psi | 73% | 3091 fps | 99.2% |
| Lovex D073.6 | <<locked>> | 80% | 37,739 psi | 59% | 2946 fps | 98.2% |
| Lovex S060 | <<locked>> | 80% | 39,958 psi | 63% | 2917 fps | 95.9% |
| Lovex S062 | <<locked>> | 80% | 34,853 psi | 55% | 2844 fps | 95.7% |
| Lovex S065 | <<locked>> | 98% | 49,995 psi | 78% | 3166 fps | 95.6% |
| Norma 201 | <<locked>> | 80% | 38,609 psi | 61% | 2927 fps | 96.9% |
| Norma 202 | <<locked>> | 80% | 38,653 psi | 61% | 2946 fps | 98.9% |
| Norma 203B | <<locked>> | 84% | 39,552 psi | 62% | 2995 fps | 95.8% |
| Norma URP | <<locked>> | 98% | 44,918 psi | 70% | 3156 fps | 95.8% |
| Ramshot Big Game | <<locked>> | 84% | 39,030 psi | 61% | 2999 fps | 95.3% |
| Ramshot TAC | <<locked>> | 84% | 47,123 psi | 74% | 3104 fps | 95% |
| Ramshot Wild Boar | <<locked>> | 80% | 40,611 psi | 64% | 3005 fps | 96% |
| Ramshot X-Terminator | <<locked>> | 80% | 44,788 psi | 70% | 3041 fps | 97% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 25,962 psi | 41% | 1867 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 80% | 46,354 psi | 73% | 3097 fps | 99.4% |
| ReloadSwiss RS 50 | <<locked>> | 94% | 53,519 psi | 84% | 3232 fps | 95.6% |
| ReloadSwiss RS 52 | 40.6 gr | 84% | 41,626 psi | 65% | 3114 fps | 95.7% |
| ReloadSwiss RS 60 | 40.3 gr | 82% | 32,184 psi | 50% | 2877 fps | 95.6% |
| ReloadSwiss RS 62 | <<locked>> | 98% | 44,802 psi | 70% | 3176 fps | 95.5% |
| Rottweil R 901 | <<locked>> | 80% | 42,206 psi | 66% | 2995 fps | 99.3% |
| Rottweil R 902 | <<locked>> | 80% | 36,521 psi | 57% | 2864 fps | 96.2% |
| Rottweil R 903 | <<locked>> | 86% | 36,840 psi | 58% | 2930 fps | 95.7% |
| Shooters World Long Rifle | <<locked>> | 98% | 49,995 psi | 78% | 3166 fps | 95.6% |
| Shooters World Match Rifle | <<locked>> | 80% | 37,739 psi | 59% | 2946 fps | 98.2% |
| Shooters World Precision | <<locked>> | 80% | 34,853 psi | 55% | 2844 fps | 95.7% |
| Shooters World Tactical Rifle | <<locked>> | 80% | 49,023 psi | 77% | 3114 fps | 98.8% |
| SNPE Vectan BA6 1/2 | <<locked>> | 80% | 54,665 psi | 86% | 2877 fps | 100% |
| SNPE Vectan SP 10 | <<locked>> | 80% | 52,185 psi | 82% | 3215 fps | 100% |
| SNPE Vectan SP 11 | <<locked>> | 86% | 38,058 psi | 60% | 2982 fps | 95% |
| SNPE Vectan SP 3 | <<locked>> | 80% | 48,718 psi | 76% | 3117 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 84% | 45,121 psi | 71% | 3068 fps | 95.1% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 37,869 psi | 59% | 2930 fps | 95.1% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 39,943 psi | 63% | 2894 fps | 99.1% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 32,837 psi | 51% | 2733 fps | 98.5% |
| Somchem S321 | <<locked>> | 80% | 44,396 psi | 70% | 3077 fps | 98.5% |
| Somchem S335 | <<locked>> | 80% | 39,726 psi | 62% | 2900 fps | 99.5% |
| Somchem S341 | <<locked>> | 80% | 38,943 psi | 61% | 2943 fps | 95.4% |
| Somchem S355 | <<locked>> | 86% | 37,681 psi | 59% | 2936 fps | 95.7% |
| Somchem S365 | <<locked>> | 92% | 33,040 psi | 52% | 2900 fps | 95.2% |
| Vihtavuori N130 | <<locked>> | 80% | 45,237 psi | 71% | 2989 fps | 100% |
| Vihtavuori N133 | <<locked>> | 80% | 40,059 psi | 63% | 2900 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 35,418 psi | 56% | 2867 fps | 99.8% |
| Vihtavuori N140 | <<locked>> | 80% | 36,535 psi | 57% | 2871 fps | 98.8% |
| Vihtavuori N150 | <<locked>> | 82% | 31,517 psi | 49% | 2749 fps | 95% |
| Vihtavuori N160 | <<locked>> | 96% | 44,396 psi | 70% | 3100 fps | 95.5% |
| Vihtavuori N530 | <<locked>> | 80% | 41,307 psi | 65% | 2986 fps | 97.6% |
| Vihtavuori N540 | <<locked>> | 80% | 35,172 psi | 55% | 2848 fps | 98% |
| Vihtavuori N550 | <<locked>> | 96% | 43,656 psi | 68% | 3100 fps | 95.1% |
| Winchester 6.5 StaBALL | <<locked>> | 90% | 37,115 psi | 58% | 2894 fps | 95.4% |
| Winchester 748 | <<locked>> | 80% | 40,263 psi | 63% | 3025 fps | 98.2% |
| Winchester StaBALL Match | <<locked>> | 80% | 37,043 psi | 58% | 2927 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 .25 WSSM loaded with the .257 | 87gr | Speer MHP. Alliant Power Pro 2000-MR delivers the highest muzzle velocity at 3,455 fps; across all powders the maximum-charge window runs from 2,037 fps to 3,455 fps. Accurate 4350 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 54–90 %, leaving at least 10 % headroom. The 87.0 gr projectile in 0.257" calls for a 1:12.0 twist; slower twists will usually not stabilise this weight. Accurate 4350, Alliant Reloder-16, Alliant Reloder-17 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 Power Pro 2000-MR, ReloadSwiss RS 52, ReloadSwiss RS 60 rank at the top here: for .25 WSSM with the .257 | 87gr | Speer MHP 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.