Load Specifications
Load data in caliber .25 WYB RPM with .257 | 133gr | Berger Elite Hunter bullet and 72 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Hodgdon Retumbo, ReloadSwiss RS 76 and Vihtavuori N560.
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 3100 | <<locked>> | 92% | 56,362 psi | 87% | 2851 fps | 100% |
| Accurate 4350 | <<locked>> | 84% | 57,305 psi | 88% | 2874 fps | 100% |
| Accurate MAGPRO | <<locked>> | 90% | 54,926 psi | 85% | 2946 fps | 98.4% |
| ADI AR 2209 | <<locked>> | 90% | 58,160 psi | 89% | 2940 fps | 99.9% |
| ADI AR 2213 | <<locked>> | 92% | 55,985 psi | 86% | 2949 fps | 99.3% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 53,954 psi | 83% | 2913 fps | 99.3% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 48,472 psi | 75% | 2874 fps | 100% |
| Alliant Power Pro Varmint | <<locked>> | 90% | 58,349 psi | 90% | 2936 fps | 99.9% |
| Alliant Reloder-16 | <<locked>> | 86% | 58,436 psi | 90% | 2930 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 90% | 57,653 psi | 89% | 2930 fps | 99.9% |
| Alliant Reloder-22 | <<locked>> | 92% | 56,260 psi | 87% | 2943 fps | 99.8% |
| Alliant Reloder-23 | <<locked>> | 94% | 57,827 psi | 89% | 2910 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 98% | 57,232 psi | 88% | 2976 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 90% | 58,552 psi | 90% | 3002 fps | 100% |
| Baschieri & Pellagri 109 | <<locked>> | 94% | 57,029 psi | 88% | 2907 fps | 97.3% |
| Bofors RP15 | <<locked>> | 94% | 55,448 psi | 85% | 2930 fps | 99.7% |
| Bofors RP30ᴾ | <<locked>> | 100% | 57,130 psi | 88% | 2986 fps | 99.7% |
| Bofors RP5 | <<locked>> | 92% | 56,260 psi | 87% | 2943 fps | 99.8% |
| Bofors RP7 | <<locked>> | 82% | 55,521 psi | 85% | 2822 fps | 99.9% |
| Hodgdon H1000 | <<locked>> | 98% | 55,825 psi | 86% | 2943 fps | 99.8% |
| Hodgdon H414 | <<locked>> | 82% | 55,085 psi | 85% | 2874 fps | 100% |
| Hodgdon H4350 | <<locked>> | 82% | 57,653 psi | 89% | 2890 fps | 99.9% |
| Hodgdon H4831 | <<locked>> | 90% | 55,593 psi | 86% | 2884 fps | 98.8% |
| Hodgdon H4831 SC | <<locked>> | 92% | 58,392 psi | 90% | 2927 fps | 99.1% |
| Hodgdon Hybrid 100V | <<locked>> | 88% | 58,479 psi | 90% | 2851 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 98% | 56,246 psi | 87% | 3054 fps | 100% |
| Hodgdon Superformance | <<locked>> | 82% | 55,434 psi | 85% | 2910 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,260 psi | 57% | 1801 fps | 100% |
| IMR 4350 | <<locked>> | 86% | 57,406 psi | 88% | 2867 fps | 100% |
| IMR 4451 Enduron | <<locked>> | 82% | 56,753 psi | 87% | 2841 fps | 100% |
| IMR 4831 | <<locked>> | 86% | 57,595 psi | 89% | 2867 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 90% | 56,536 psi | 87% | 2867 fps | 99% |
| IMR 7828 SSC | <<locked>> | 94% | 58,059 psi | 89% | 2989 fps | 99.5% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 44,150 psi | 68% | 2782 fps | 97.6% |
| Lovex S065 | <<locked>> | 84% | 57,624 psi | 89% | 2841 fps | 100% |
| Lovex S070 | <<locked>> | 84% | 56,043 psi | 86% | 2841 fps | 100% |
| Lovex S071 | <<locked>> | 98% | 57,580 psi | 89% | 2867 fps | 100% |
| Norma 204 | <<locked>> | 86% | 58,639 psi | 90% | 2927 fps | 99.8% |
| Norma 217ᴾ | <<locked>> | 100% | 44,527 psi | 69% | 2808 fps | 99.4% |
| Norma MRP | <<locked>> | 90% | 56,333 psi | 87% | 2966 fps | 100% |
| Norma URP | <<locked>> | 84% | 55,724 psi | 86% | 2858 fps | 100% |
| Ramshot Grand | <<locked>> | 92% | 55,042 psi | 85% | 2949 fps | 99.5% |
| Ramshot Hunter | <<locked>> | 86% | 58,320 psi | 90% | 2923 fps | 100% |
| Ramshot Magnum | <<locked>> | 96% | 57,479 psi | 88% | 2943 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,159 psi | 59% | 1847 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 84% | 57,551 psi | 89% | 2900 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 84% | 55,970 psi | 86% | 2930 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 98% | 57,014 psi | 88% | 3051 fps | 100% |
| ReloadSwiss RS 80ᴾ | <<locked>> | 100% | 56,376 psi | 87% | 3012 fps | 98.9% |
| Rottweil R 904 | <<locked>> | 88% | 55,405 psi | 85% | 2851 fps | 99.2% |
| Rottweil R 905 | <<locked>> | 90% | 57,406 psi | 88% | 2920 fps | 99.9% |
| Rottweil R 907 | <<locked>> | 82% | 55,521 psi | 85% | 2822 fps | 99.9% |
| Shooters World Long Rifle | <<locked>> | 84% | 57,624 psi | 89% | 2841 fps | 100% |
| Shooters World SW4350 | <<locked>> | 84% | 56,043 psi | 86% | 2841 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 84% | 56,637 psi | 87% | 2795 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 90% | 56,971 psi | 88% | 2917 fps | 99.9% |
| Somchem S361 | <<locked>> | 88% | 56,971 psi | 88% | 2848 fps | 98.9% |
| Somchem S365 | <<locked>> | 86% | 56,623 psi | 87% | 2864 fps | 100% |
| Somchem S385 | <<locked>> | 90% | 57,754 psi | 89% | 2890 fps | 100% |
| Vihtavuori N150 | <<locked>> | 82% | 57,856 psi | 89% | 2782 fps | 100% |
| Vihtavuori N160 | <<locked>> | 84% | 57,217 psi | 88% | 2848 fps | 100% |
| Vihtavuori N165 | <<locked>> | 94% | 57,290 psi | 88% | 2871 fps | 100% |
| Vihtavuori N550 | <<locked>> | 84% | 56,347 psi | 87% | 2851 fps | 100% |
| Vihtavuori N555 | <<locked>> | 90% | 56,231 psi | 87% | 2887 fps | 100% |
| Vihtavuori N560 | <<locked>> | 90% | 55,999 psi | 86% | 2963 fps | 99% |
| Vihtavuori N565 | <<locked>> | 96% | 55,999 psi | 86% | 2943 fps | 99.2% |
| Vihtavuori N568ᴾ | <<locked>> | 100% | 57,145 psi | 88% | 3012 fps | 98.5% |
| Vihtavuori N570ᴾ | <<locked>> | 100% | 53,795 psi | 83% | 2999 fps | 96.2% |
| Winchester 6.5 StaBALL | <<locked>> | 84% | 56,637 psi | 87% | 2802 fps | 100% |
| Winchester 760 | <<locked>> | 82% | 55,405 psi | 85% | 2881 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 94% | 56,550 psi | 87% | 2995 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 92% | 57,667 psi | 89% | 2887 fps | 99.8% |
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 3100 | <<locked>> | 80% | 37,768 psi | 58% | 2526 fps | 98.8% |
| Accurate 4350 | <<locked>> | 80% | 50,198 psi | 77% | 2769 fps | 100% |
| Accurate MAGPRO | <<locked>> | 82% | 41,611 psi | 64% | 2694 fps | 95.2% |
| ADI AR 2209 | <<locked>> | 80% | 41,640 psi | 64% | 2648 fps | 97.6% |
| ADI AR 2213 | <<locked>> | 82% | 39,958 psi | 61% | 2644 fps | 95.8% |
| ADI AR 2217 | <<locked>> | 90% | 38,653 psi | 59% | 2612 fps | 95.7% |
| ADI AR 2225 | <<locked>> | 86% | 30,603 psi | 47% | 2454 fps | 95.5% |
| Alliant Power Pro Varmint | <<locked>> | 80% | 42,134 psi | 65% | 2651 fps | 97.7% |
| Alliant Reloder-16 | <<locked>> | 80% | 47,935 psi | 74% | 2772 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 41,756 psi | 64% | 2644 fps | 97.7% |
| Alliant Reloder-22 | <<locked>> | 80% | 37,579 psi | 58% | 2589 fps | 96.5% |
| Alliant Reloder-23 | <<locked>> | 80% | 36,289 psi | 56% | 2546 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 31,415 psi | 48% | 2464 fps | 97.7% |
| Alliant Reloder-26 | <<locked>> | 80% | 40,190 psi | 62% | 2694 fps | 99.9% |
| Baschieri & Pellagri 109 | <<locked>> | 88% | 47,514 psi | 73% | 2736 fps | 95% |
| Bofors RP15 | <<locked>> | 80% | 35,128 psi | 54% | 2530 fps | 95.5% |
| Bofors RP30 | <<locked>> | 88% | 38,058 psi | 59% | 2628 fps | 95.9% |
| Bofors RP5 | <<locked>> | 80% | 37,579 psi | 58% | 2589 fps | 96.5% |
| Bofors RP7 | <<locked>> | 80% | 52,127 psi | 80% | 2769 fps | 99.8% |
| Hodgdon H1000 | <<locked>> | 86% | 36,941 psi | 57% | 2575 fps | 95.8% |
| Hodgdon H414 | <<locked>> | 80% | 51,721 psi | 80% | 2822 fps | 99.9% |
| Hodgdon H4350 | <<locked>> | 80% | 53,882 psi | 83% | 2831 fps | 99.7% |
| Hodgdon H4831 | <<locked>> | 80% | 39,653 psi | 61% | 2585 fps | 95% |
| Hodgdon H4831 SC | <<locked>> | 82% | 41,901 psi | 64% | 2635 fps | 95.8% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 45,223 psi | 70% | 2651 fps | 100% |
| Hodgdon Retumbo | 50.3 gr | 82% | 32,851 psi | 51% | 2549 fps | 95.1% |
| Hodgdon Superformance | <<locked>> | 80% | 51,692 psi | 80% | 2851 fps | 99.9% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,949 psi | 43% | 1611 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 47,398 psi | 73% | 2703 fps | 99.4% |
| IMR 4451 Enduron | <<locked>> | 80% | 53,374 psi | 82% | 2789 fps | 100% |
| IMR 4831 | <<locked>> | 80% | 47,587 psi | 73% | 2713 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 41,220 psi | 63% | 2585 fps | 95.8% |
| IMR 7828 SSC | <<locked>> | 82% | 38,421 psi | 59% | 2621 fps | 95.4% |
| IMR 8133 Enduron | <<locked>> | 96% | 38,580 psi | 59% | 2661 fps | 95.9% |
| Lovex S065 | <<locked>> | 80% | 50,937 psi | 78% | 2740 fps | 100% |
| Lovex S070 | <<locked>> | 80% | 49,516 psi | 76% | 2736 fps | 99.9% |
| Lovex S071 | <<locked>> | 80% | 32,474 psi | 50% | 2402 fps | 97.3% |
| Norma 204 | <<locked>> | 80% | 47,863 psi | 74% | 2746 fps | 98.8% |
| Norma 217 | <<locked>> | 90% | 31,734 psi | 49% | 2510 fps | 95.4% |
| Norma MRP | <<locked>> | 80% | 39,523 psi | 61% | 2657 fps | 98.4% |
| Norma URP | <<locked>> | 80% | 48,994 psi | 75% | 2753 fps | 100% |
| Ramshot Grand | <<locked>> | 82% | 38,058 psi | 59% | 2625 fps | 95.7% |
| Ramshot Hunter | <<locked>> | 80% | 47,805 psi | 74% | 2753 fps | 99.9% |
| Ramshot Magnum | <<locked>> | 80% | 31,749 psi | 49% | 2444 fps | 95.1% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,805 psi | 44% | 1654 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 50,111 psi | 77% | 2789 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 48,443 psi | 75% | 2812 fps | 100% |
| ReloadSwiss RS 76 | 53.8 gr | 82% | 31,879 psi | 49% | 2520 fps | 96% |
| ReloadSwiss RS 80 | <<locked>> | 92% | 41,568 psi | 64% | 2740 fps | 95.4% |
| Rottweil R 904 | <<locked>> | 80% | 42,902 psi | 66% | 2628 fps | 96.9% |
| Rottweil R 905 | <<locked>> | 80% | 41,133 psi | 63% | 2631 fps | 97.7% |
| Rottweil R 907 | <<locked>> | 80% | 52,127 psi | 80% | 2769 fps | 99.8% |
| Shooters World Long Rifle | <<locked>> | 80% | 50,937 psi | 78% | 2740 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 49,516 psi | 76% | 2736 fps | 99.9% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 49,893 psi | 77% | 2690 fps | 99.8% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 40,799 psi | 63% | 2625 fps | 97.6% |
| Somchem S361 | <<locked>> | 80% | 43,714 psi | 67% | 2618 fps | 96.3% |
| Somchem S365 | <<locked>> | 80% | 46,151 psi | 71% | 2707 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 41,655 psi | 64% | 2615 fps | 98.5% |
| Vihtavuori N150 | <<locked>> | 80% | 54,317 psi | 84% | 2733 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 50,343 psi | 77% | 2746 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 36,230 psi | 56% | 2490 fps | 96.7% |
| Vihtavuori N550 | <<locked>> | 80% | 49,763 psi | 77% | 2753 fps | 100% |
| Vihtavuori N555 | <<locked>> | 80% | 40,596 psi | 62% | 2621 fps | 100% |
| Vihtavuori N560 | 50.9 gr | 80% | 39,523 psi | 61% | 2648 fps | 95.2% |
| Vihtavuori N565 | <<locked>> | 86% | 40,089 psi | 62% | 2648 fps | 95.7% |
| Vihtavuori N568 | <<locked>> | 92% | 42,989 psi | 66% | 2756 fps | 95.2% |
| Vihtavuori N570 | <<locked>> | 98% | 50,299 psi | 77% | 2933 fps | 95.3% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 49,458 psi | 76% | 2700 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 51,721 psi | 80% | 2822 fps | 99.9% |
| Winchester StaBALL HD | <<locked>> | 80% | 32,982 psi | 51% | 2582 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 38,159 psi | 59% | 2539 fps | 96.7% |
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 72 powders for .25 WYB RPM loaded with the .257 | 133gr | Berger Elite Hunter. Hodgdon Retumbo delivers the highest muzzle velocity at 3,054 fps; across all powders the maximum-charge window runs from 1,801 fps to 3,054 fps. ADI AR 2217 gives the best case fill at 100 %, and 72 of the 72 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (448 MPa), the top charges use 57–90 %, leaving at least 10 % headroom. The 133.0 gr projectile in 0.257" calls for a 1:8.0 twist; slower twists will usually not stabilise this weight. ADI AR 2217, ADI AR 2225, Bofors RP30 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. Hodgdon Retumbo, ReloadSwiss RS 76, Vihtavuori N560 rank at the top here: for .25 WYB RPM with the .257 | 133gr | Berger Elite 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.