Load Specifications
Load data in caliber .25 WYB RPM with .257 | 87gr | Speer Hot-Cor bullet and 86 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Alliant Reloder-26, Alliant Reloder-17 and Hodgdon H414.
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 2495 | <<locked>> | 82% | 56,304 psi | 87% | 3307 fps | 100% |
| Accurate 2700 | <<locked>> | 84% | 57,479 psi | 88% | 3366 fps | 97.9% |
| Accurate 3100ᴾ | <<locked>> | 100% | 56,637 psi | 87% | 3406 fps | 99.1% |
| Accurate 4064 | <<locked>> | 84% | 56,840 psi | 87% | 3366 fps | 100% |
| Accurate 4350 | <<locked>> | 92% | 58,392 psi | 90% | 3478 fps | 99.9% |
| ADI AR 2206H | <<locked>> | 82% | 58,813 psi | 90% | 3451 fps | 100% |
| ADI AR 2208 | <<locked>> | 86% | 56,623 psi | 87% | 3396 fps | 99.9% |
| ADI AR 2209 | <<locked>> | 96% | 55,390 psi | 85% | 3448 fps | 96.8% |
| Alliant Power Pro 2000-MR | <<locked>> | 82% | 56,188 psi | 86% | 3527 fps | 100% |
| Alliant Reloder- TS 15.5 | <<locked>> | 86% | 57,508 psi | 88% | 3422 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 84% | 57,653 psi | 89% | 3445 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 92% | 54,984 psi | 85% | 3474 fps | 99.9% |
| Alliant Reloder-17 | <<locked>> | 88% | 56,637 psi | 87% | 3507 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 98% | 58,697 psi | 90% | 3501 fps | 97.5% |
| Alliant Reloder-22ᴾ | <<locked>> | 100% | 56,275 psi | 87% | 3494 fps | 97.2% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 53,156 psi | 82% | 3425 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 46,021 psi | 71% | 3320 fps | 98.1% |
| Alliant Reloder-26 | <<locked>> | 98% | 57,827 psi | 89% | 3583 fps | 99.9% |
| Bofors RP3 | <<locked>> | 84% | 54,882 psi | 84% | 3379 fps | 100% |
| Bofors RP5ᴾ | <<locked>> | 100% | 56,275 psi | 87% | 3494 fps | 97.2% |
| Bofors RP7 | <<locked>> | 90% | 58,015 psi | 89% | 3415 fps | 98.2% |
| Hodgdon H380 | <<locked>> | 84% | 55,216 psi | 85% | 3389 fps | 99.5% |
| Hodgdon H414 | <<locked>> | 90% | 56,594 psi | 87% | 3465 fps | 98.5% |
| Hodgdon H4350 | <<locked>> | 88% | 56,028 psi | 86% | 3419 fps | 97.2% |
| Hodgdon Hybrid 100V | <<locked>> | 94% | 55,564 psi | 85% | 3396 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 82% | 56,507 psi | 87% | 3438 fps | 100% |
| Hodgdon Superformance | <<locked>> | 90% | 57,232 psi | 88% | 3497 fps | 98.3% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,405 psi | 56% | 2211 fps | 100% |
| Hodgdon VARGET | <<locked>> | 82% | 57,043 psi | 88% | 3406 fps | 100% |
| IMR 4064 | <<locked>> | 84% | 55,898 psi | 86% | 3376 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 84% | 58,798 psi | 90% | 3415 fps | 98.7% |
| IMR 4350 | <<locked>> | 92% | 55,477 psi | 85% | 3383 fps | 97.8% |
| IMR 4451 Enduron | <<locked>> | 88% | 56,086 psi | 86% | 3386 fps | 98.2% |
| IMR 4831 | <<locked>> | 94% | 58,653 psi | 90% | 3465 fps | 99.9% |
| IMR 4895 | <<locked>> | 82% | 55,477 psi | 85% | 3419 fps | 100% |
| Lovex S060 | <<locked>> | 82% | 57,392 psi | 88% | 3366 fps | 100% |
| Lovex S062 | <<locked>> | 84% | 56,405 psi | 87% | 3376 fps | 100% |
| Lovex S065 | <<locked>> | 90% | 56,246 psi | 87% | 3386 fps | 99.2% |
| Lovex S070 | <<locked>> | 92% | 57,725 psi | 89% | 3428 fps | 98.7% |
| Lovex S071ᴾ | <<locked>> | 100% | 46,673 psi | 72% | 3222 fps | 97.4% |
| Norma 201 | <<locked>> | 82% | 57,580 psi | 89% | 3389 fps | 100% |
| Norma 202 | <<locked>> | 82% | 58,363 psi | 90% | 3386 fps | 100% |
| Norma 203B | <<locked>> | 84% | 56,942 psi | 88% | 3428 fps | 100% |
| Norma 204 | <<locked>> | 92% | 56,579 psi | 87% | 3442 fps | 96.9% |
| Norma MRP | <<locked>> | 98% | 55,840 psi | 86% | 3524 fps | 98.4% |
| Norma URP | <<locked>> | 92% | 56,608 psi | 87% | 3455 fps | 99.8% |
| Ramshot Big Game | <<locked>> | 84% | 58,233 psi | 90% | 3455 fps | 100% |
| Ramshot Hunter | <<locked>> | 92% | 55,550 psi | 85% | 3442 fps | 98.9% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 49,429 psi | 76% | 3330 fps | 96.4% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 36,999 psi | 57% | 2260 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 84% | 55,085 psi | 85% | 3369 fps | 98.6% |
| ReloadSwiss RS 60 | <<locked>> | 86% | 55,883 psi | 86% | 3501 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 92% | 58,276 psi | 90% | 3491 fps | 99.8% |
| ReloadSwiss RS 70 | <<locked>> | 92% | 56,884 psi | 88% | 3527 fps | 99.8% |
| Rottweil R 902 | <<locked>> | 84% | 58,276 psi | 90% | 3389 fps | 100% |
| Rottweil R 903 | <<locked>> | 88% | 58,798 psi | 90% | 3435 fps | 100% |
| Rottweil R 904 | <<locked>> | 96% | 57,130 psi | 88% | 3419 fps | 95.9% |
| Rottweil R 905 | <<locked>> | 98% | 57,972 psi | 89% | 3484 fps | 97.5% |
| Rottweil R 907 | <<locked>> | 90% | 58,015 psi | 89% | 3415 fps | 98.2% |
| Shooters World Long Rifle | <<locked>> | 90% | 56,246 psi | 87% | 3386 fps | 99.2% |
| Shooters World Precision | <<locked>> | 84% | 56,405 psi | 87% | 3376 fps | 100% |
| Shooters World SW4350 | <<locked>> | 92% | 57,725 psi | 89% | 3428 fps | 98.7% |
| SNPE Vectan SP 11 | <<locked>> | 86% | 56,869 psi | 87% | 3442 fps | 100% |
| SNPE Vectan SP 9 | <<locked>> | 82% | 57,522 psi | 88% | 3415 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 82% | 57,972 psi | 89% | 3310 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 86% | 55,782 psi | 86% | 3258 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 90% | 55,985 psi | 86% | 3323 fps | 98.3% |
| SNPE Vectan Tubal 8000 | <<locked>> | 98% | 57,479 psi | 88% | 3478 fps | 97.4% |
| Somchem S335 | <<locked>> | 82% | 57,957 psi | 89% | 3307 fps | 100% |
| Somchem S355 | <<locked>> | 88% | 58,552 psi | 90% | 3432 fps | 100% |
| Somchem S365 | <<locked>> | 94% | 56,173 psi | 86% | 3455 fps | 100% |
| Somchem S385 | <<locked>> | 98% | 58,784 psi | 90% | 3458 fps | 98.3% |
| Vihtavuori N133 | <<locked>> | 82% | 58,465 psi | 90% | 3291 fps | 100% |
| Vihtavuori N135 | <<locked>> | 84% | 58,682 psi | 90% | 3346 fps | 100% |
| Vihtavuori N140 | <<locked>> | 82% | 55,434 psi | 85% | 3304 fps | 100% |
| Vihtavuori N150 | <<locked>> | 88% | 56,347 psi | 87% | 3343 fps | 100% |
| Vihtavuori N160 | <<locked>> | 90% | 55,172 psi | 85% | 3389 fps | 99.7% |
| Vihtavuori N165ᴾ | <<locked>> | 100% | 54,331 psi | 84% | 3356 fps | 97.2% |
| Vihtavuori N540 | <<locked>> | 84% | 57,203 psi | 88% | 3350 fps | 100% |
| Vihtavuori N550 | <<locked>> | 92% | 58,131 psi | 89% | 3455 fps | 99.8% |
| Vihtavuori N555 | <<locked>> | 98% | 55,390 psi | 85% | 3451 fps | 99.9% |
| Winchester 6.5 StaBALL | <<locked>> | 90% | 54,911 psi | 84% | 3346 fps | 100% |
| Winchester 760 | <<locked>> | 90% | 56,594 psi | 87% | 3465 fps | 98.5% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 48,689 psi | 75% | 3481 fps | 100% |
| Winchester StaBALL Match | <<locked>> | 82% | 57,754 psi | 89% | 3422 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 98% | 55,027 psi | 85% | 3376 fps | 96.7% |
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 2495 | <<locked>> | 80% | 52,649 psi | 81% | 3248 fps | 100% |
| Accurate 2700 | <<locked>> | 80% | 50,285 psi | 77% | 3232 fps | 96.5% |
| Accurate 3100 | <<locked>> | 90% | 39,987 psi | 62% | 3068 fps | 95.4% |
| Accurate 4064 | <<locked>> | 80% | 49,864 psi | 77% | 3248 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 38,101 psi | 59% | 3054 fps | 96.5% |
| ADI AR 2206H | <<locked>> | 80% | 55,129 psi | 85% | 3386 fps | 100% |
| ADI AR 2208 | <<locked>> | 80% | 46,876 psi | 72% | 3209 fps | 99.1% |
| ADI AR 2209 | <<locked>> | 94% | 51,793 psi | 80% | 3376 fps | 95.9% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 52,228 psi | 80% | 3455 fps | 99.7% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 47,529 psi | 73% | 3238 fps | 99.8% |
| Alliant Reloder-15 | <<locked>> | 80% | 50,633 psi | 78% | 3317 fps | 99.6% |
| Alliant Reloder-16 | <<locked>> | 80% | 37,072 psi | 57% | 3068 fps | 96.5% |
| Alliant Reloder-17 | 54.7 gr | 80% | 42,337 psi | 65% | 3225 fps | 99.3% |
| Alliant Reloder-19 | <<locked>> | 92% | 48,211 psi | 74% | 3294 fps | 95% |
| Alliant Reloder-22 | <<locked>> | 96% | 48,834 psi | 75% | 3346 fps | 95.3% |
| Alliant Reloder-23 | <<locked>> | 84% | 31,111 psi | 48% | 2897 fps | 95.6% |
| Alliant Reloder-25 | <<locked>> | 94% | 37,753 psi | 58% | 3104 fps | 95.1% |
| Alliant Reloder-26 | 60.3 gr | 86% | 36,579 psi | 56% | 3110 fps | 95.5% |
| Bofors RP3 | <<locked>> | 80% | 47,993 psi | 74% | 3251 fps | 99.9% |
| Bofors RP5 | <<locked>> | 96% | 48,834 psi | 75% | 3346 fps | 95.3% |
| Bofors RP7 | <<locked>> | 82% | 44,976 psi | 69% | 3153 fps | 95.2% |
| Hodgdon H380 | <<locked>> | 80% | 48,428 psi | 75% | 3258 fps | 98.6% |
| Hodgdon H414 | 54.8 gr | 82% | 42,917 psi | 66% | 3179 fps | 95.2% |
| Hodgdon H4350 | <<locked>> | 84% | 48,979 psi | 75% | 3278 fps | 95.5% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 34,476 psi | 53% | 2943 fps | 97.2% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 52,939 psi | 81% | 3376 fps | 100% |
| Hodgdon Superformance | <<locked>> | 84% | 45,629 psi | 70% | 3268 fps | 95.7% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,151 psi | 42% | 1985 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 53,490 psi | 82% | 3343 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 49,298 psi | 76% | 3251 fps | 99.5% |
| IMR 4166 Enduron | <<locked>> | 80% | 51,488 psi | 79% | 3281 fps | 97.5% |
| IMR 4350 | <<locked>> | 86% | 45,759 psi | 70% | 3186 fps | 95.5% |
| IMR 4451 Enduron | <<locked>> | 80% | 43,439 psi | 67% | 3123 fps | 95.3% |
| IMR 4831 | <<locked>> | 80% | 36,637 psi | 56% | 3002 fps | 96.1% |
| IMR 4895 | <<locked>> | 80% | 51,967 psi | 80% | 3353 fps | 99.9% |
| Lovex S060 | <<locked>> | 80% | 53,853 psi | 83% | 3307 fps | 100% |
| Lovex S062 | <<locked>> | 80% | 49,545 psi | 76% | 3251 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 41,017 psi | 63% | 3064 fps | 96.1% |
| Lovex S070 | <<locked>> | 82% | 41,989 psi | 65% | 3104 fps | 95.1% |
| Lovex S071 | <<locked>> | 96% | 41,046 psi | 63% | 3094 fps | 95.7% |
| Norma 201 | <<locked>> | 80% | 53,940 psi | 83% | 3327 fps | 100% |
| Norma 202 | <<locked>> | 80% | 54,679 psi | 84% | 3330 fps | 100% |
| Norma 203B | <<locked>> | 80% | 50,009 psi | 77% | 3304 fps | 99.8% |
| Norma 204 | <<locked>> | 88% | 49,197 psi | 76% | 3297 fps | 95% |
| Norma MRP | <<locked>> | 92% | 45,136 psi | 69% | 3301 fps | 95.8% |
| Norma URP | <<locked>> | 80% | 37,942 psi | 58% | 3054 fps | 96.3% |
| Ramshot Big Game | <<locked>> | 80% | 50,604 psi | 78% | 3320 fps | 99.8% |
| Ramshot Hunter | <<locked>> | 82% | 39,537 psi | 61% | 3097 fps | 95% |
| Ramshot Magnum | <<locked>> | 98% | 45,730 psi | 70% | 3251 fps | 95.2% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,557 psi | 42% | 2031 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 48,254 psi | 74% | 3232 fps | 97.3% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 44,947 psi | 69% | 3294 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 37,985 psi | 58% | 3068 fps | 96% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 36,854 psi | 57% | 3068 fps | 95.1% |
| Rottweil R 902 | <<locked>> | 80% | 51,445 psi | 79% | 3274 fps | 100% |
| Rottweil R 903 | <<locked>> | 80% | 45,208 psi | 70% | 3186 fps | 99.6% |
| Rottweil R 904 | <<locked>> | 94% | 53,505 psi | 82% | 3346 fps | 95% |
| Rottweil R 905 | <<locked>> | 94% | 50,531 psi | 78% | 3346 fps | 95.8% |
| Rottweil R 907 | <<locked>> | 82% | 44,976 psi | 69% | 3153 fps | 95.2% |
| Shooters World Long Rifle | <<locked>> | 80% | 41,017 psi | 63% | 3064 fps | 96.1% |
| Shooters World Precision | <<locked>> | 80% | 49,545 psi | 76% | 3251 fps | 100% |
| Shooters World SW4350 | <<locked>> | 82% | 41,989 psi | 65% | 3104 fps | 95.1% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 46,296 psi | 71% | 3241 fps | 99.3% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 53,737 psi | 83% | 3350 fps | 99.9% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 54,534 psi | 84% | 3261 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 46,166 psi | 71% | 3094 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 82% | 43,076 psi | 66% | 3068 fps | 95.4% |
| SNPE Vectan Tubal 8000 | <<locked>> | 94% | 50,082 psi | 77% | 3337 fps | 95.7% |
| Somchem S335 | <<locked>> | 80% | 54,433 psi | 84% | 3251 fps | 100% |
| Somchem S355 | <<locked>> | 80% | 45,339 psi | 70% | 3182 fps | 99.5% |
| Somchem S365 | <<locked>> | 80% | 34,447 psi | 53% | 2999 fps | 98.4% |
| Somchem S385 | <<locked>> | 90% | 44,889 psi | 69% | 3186 fps | 95.1% |
| Vihtavuori N133 | <<locked>> | 80% | 55,071 psi | 85% | 3241 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 51,605 psi | 79% | 3238 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 51,982 psi | 80% | 3248 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 43,424 psi | 67% | 3107 fps | 99.9% |
| Vihtavuori N160 | <<locked>> | 80% | 39,233 psi | 60% | 3054 fps | 96.7% |
| Vihtavuori N165 | <<locked>> | 96% | 47,485 psi | 73% | 3225 fps | 95.5% |
| Vihtavuori N540 | <<locked>> | 80% | 50,372 psi | 77% | 3235 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 38,899 psi | 60% | 3054 fps | 96.4% |
| Vihtavuori N555 | <<locked>> | 84% | 34,548 psi | 53% | 2989 fps | 95.8% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 38,624 psi | 59% | 3018 fps | 98.8% |
| Winchester 760 | <<locked>> | 82% | 43,178 psi | 66% | 3186 fps | 95.2% |
| Winchester StaBALL HD | <<locked>> | 86% | 29,588 psi | 46% | 2927 fps | 95.5% |
| Winchester StaBALL Match | <<locked>> | 80% | 54,099 psi | 83% | 3360 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 96% | 51,300 psi | 79% | 3310 fps | 95.8% |
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 WYB RPM loaded with the .257 | 87gr | Speer Hot-Cor. Alliant Reloder-26 delivers the highest muzzle velocity at 3,583 fps; across all powders the maximum-charge window runs from 2,211 fps to 3,583 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 (448 MPa), the top charges use 56–90 %, leaving at least 10 % headroom. The 87.0 gr projectile in 0.257" calls for a 1:14.5 twist; slower twists will usually not stabilise this weight. Accurate 3100, ADI AR 2213, Alliant Reloder-22 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-26, Alliant Reloder-17, Hodgdon H414 rank at the top here: for .25 WYB RPM with the .257 | 87gr | Speer Hot-Cor they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, Accurate MAGPRO, Baschieri & Pellagri 109, Bofors RP30 burn incompletely and react more sensitively to barrel length and temperature. Always begin at the start load and work up in small increments while checking case and primer for pressure signs.