Load Specifications
Load data in caliber .256 Mag. Gibbs with .257 | 90gr | Reichenberg HDB Universal bullet and 41 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are ReloadSwiss RS 60, Alliant Reloder-17 and Somchem S365.
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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Max Load - Barrel Length: 24"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2495 | <<locked>> | 84% | 43,613 psi | 88% | 3002 fps | 100% |
| Accurate 4064 | <<locked>> | 86% | 43,932 psi | 89% | 3045 fps | 99.9% |
| ADI AR 2208 | <<locked>> | 86% | 43,178 psi | 88% | 3005 fps | 96.6% |
| Alliant Power Pro 2000-MR | <<locked>> | 84% | 43,598 psi | 88% | 3140 fps | 96.4% |
| Alliant Reloder- TS 15.5 | <<locked>> | 86% | 42,525 psi | 86% | 3025 fps | 98% |
| Alliant Reloder-15 | <<locked>> | 84% | 42,960 psi | 87% | 3038 fps | 96.7% |
| Alliant Reloder-17 | <<locked>> | 90% | 42,366 psi | 86% | 3114 fps | 97.7% |
| Baschieri & Pellagri 107 | <<locked>> | 82% | 44,034 psi | 89% | 3054 fps | 96.4% |
| Bofors RP3 | <<locked>> | 86% | 42,511 psi | 86% | 3031 fps | 98.1% |
| Hodgdon Hybrid 100V | <<locked>> | 98% | 44,135 psi | 90% | 3077 fps | 98% |
| Hodgdon LEVERevolution | <<locked>> | 84% | 43,961 psi | 89% | 3097 fps | 98.4% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 35,070 psi | 71% | 2031 fps | 100% |
| Hodgdon VARGET | <<locked>> | 82% | 43,352 psi | 88% | 3018 fps | 97.8% |
| IMR 3031 | <<locked>> | 82% | 44,556 psi | 90% | 3081 fps | 100% |
| IMR 4064 | <<locked>> | 84% | 42,438 psi | 86% | 2982 fps | 96.6% |
| IMR 4831 | <<locked>> | 96% | 43,729 psi | 89% | 3077 fps | 96.3% |
| IMR 4895 | <<locked>> | 84% | 43,976 psi | 89% | 3074 fps | 97.6% |
| Lovex D073.6 | <<locked>> | 82% | 43,816 psi | 89% | 3041 fps | 99.6% |
| Lovex S062 | <<locked>> | 84% | 42,308 psi | 86% | 2992 fps | 98.3% |
| Norma 201 | <<locked>> | 82% | 43,932 psi | 89% | 3015 fps | 98.6% |
| Norma 202 | <<locked>> | 82% | 44,106 psi | 89% | 3025 fps | 99.8% |
| Norma 203B | <<locked>> | 84% | 42,279 psi | 86% | 3025 fps | 97.1% |
| Ramshot Big Game | <<locked>> | 84% | 42,003 psi | 85% | 3035 fps | 96.8% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 35,404 psi | 72% | 2073 fps | 100% |
| ReloadSwiss RS 52 | <<locked>> | 82% | 42,003 psi | 85% | 3087 fps | 96.3% |
| ReloadSwiss RS 60 | <<locked>> | 88% | 42,308 psi | 86% | 3130 fps | 99.5% |
| Rottweil R 902 | <<locked>> | 84% | 44,208 psi | 90% | 3012 fps | 98.6% |
| Rottweil R 903 | <<locked>> | 88% | 42,366 psi | 86% | 3022 fps | 97.8% |
| Shooters World Match Rifle | <<locked>> | 82% | 43,816 psi | 89% | 3041 fps | 99.6% |
| Shooters World Precision | <<locked>> | 84% | 42,308 psi | 86% | 2992 fps | 98.3% |
| SNPE Vectan SP 11 | <<locked>> | 88% | 43,859 psi | 89% | 3084 fps | 97.4% |
| SNPE Vectan SP 9 | <<locked>> | 82% | 43,134 psi | 87% | 3015 fps | 97.2% |
| SNPE Vectan Tubal 5000 | <<locked>> | 86% | 42,598 psi | 86% | 2920 fps | 100% |
| Somchem S355 | <<locked>> | 88% | 43,120 psi | 87% | 3028 fps | 97.8% |
| Somchem S365 | <<locked>> | 98% | 43,410 psi | 88% | 3136 fps | 99.1% |
| Vihtavuori N135 | <<locked>> | 84% | 43,627 psi | 88% | 3002 fps | 100% |
| Vihtavuori N140 | <<locked>> | 84% | 44,570 psi | 90% | 3009 fps | 99.9% |
| Vihtavuori N150 | <<locked>> | 90% | 44,266 psi | 90% | 3018 fps | 99.1% |
| Vihtavuori N540 | <<locked>> | 84% | 42,902 psi | 87% | 2989 fps | 99.7% |
| Winchester 6.5 StaBALL | <<locked>> | 92% | 42,496 psi | 86% | 2995 fps | 97.8% |
| Winchester StaBALL Match | <<locked>> | 82% | 42,612 psi | 86% | 3022 fps | 97.7% |
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% | 38,218 psi | 78% | 2890 fps | 100% |
| Accurate 4064 | <<locked>> | 80% | 36,114 psi | 73% | 2871 fps | 99% |
| ADI AR 2208 | <<locked>> | 82% | 38,116 psi | 77% | 2884 fps | 95% |
| Alliant Power Pro 2000-MR | <<locked>> | 82% | 40,828 psi | 83% | 3071 fps | 95.4% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 35,041 psi | 71% | 2841 fps | 95.8% |
| Alliant Reloder-15 | <<locked>> | 80% | 37,855 psi | 77% | 2917 fps | 95.1% |
| Alliant Reloder-17 | 44.4 gr | 86% | 37,173 psi | 75% | 2979 fps | 95.8% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 40,973 psi | 83% | 2986 fps | 95.4% |
| Bofors RP3 | <<locked>> | 80% | 34,606 psi | 70% | 2841 fps | 95.7% |
| Hodgdon Hybrid 100V | <<locked>> | 92% | 36,535 psi | 74% | 2900 fps | 95.8% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 38,174 psi | 77% | 2963 fps | 96.9% |
| Hodgdon TrailBoss | <<locked>> | 80% | 26,092 psi | 53% | 1818 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 40,567 psi | 82% | 2956 fps | 97.1% |
| IMR 3031 | <<locked>> | 80% | 41,510 psi | 84% | 3018 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 37,376 psi | 76% | 2861 fps | 95% |
| IMR 4831 | <<locked>> | 94% | 40,872 psi | 83% | 3012 fps | 95.4% |
| IMR 4895 | <<locked>> | 80% | 38,740 psi | 79% | 2953 fps | 96.1% |
| Lovex D073.6 | <<locked>> | 80% | 40,683 psi | 83% | 2972 fps | 99.1% |
| Lovex S062 | <<locked>> | 80% | 37,275 psi | 76% | 2871 fps | 97% |
| Norma 201 | <<locked>> | 80% | 41,104 psi | 83% | 2953 fps | 98% |
| Norma 202 | <<locked>> | 80% | 41,249 psi | 84% | 2966 fps | 99.6% |
| Norma 203B | <<locked>> | 80% | 37,231 psi | 76% | 2904 fps | 95.5% |
| Ramshot Big Game | <<locked>> | 80% | 36,579 psi | 74% | 2904 fps | 95% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 26,223 psi | 53% | 1857 fps | 100% |
| ReloadSwiss RS 52 | <<locked>> | 80% | 39,117 psi | 79% | 3015 fps | 95.4% |
| ReloadSwiss RS 60 | 41.3 gr | 80% | 32,329 psi | 66% | 2854 fps | 96.4% |
| Rottweil R 902 | <<locked>> | 80% | 38,986 psi | 79% | 2894 fps | 97.5% |
| Rottweil R 903 | <<locked>> | 82% | 34,737 psi | 70% | 2838 fps | 95.4% |
| Shooters World Match Rifle | <<locked>> | 80% | 40,683 psi | 83% | 2972 fps | 99.1% |
| Shooters World Precision | <<locked>> | 80% | 37,275 psi | 76% | 2871 fps | 97% |
| SNPE Vectan SP 11 | <<locked>> | 84% | 38,406 psi | 78% | 2956 fps | 95.8% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 40,408 psi | 82% | 2956 fps | 96.5% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 35,172 psi | 71% | 2756 fps | 99.3% |
| Somchem S355 | <<locked>> | 82% | 35,795 psi | 73% | 2851 fps | 95.6% |
| Somchem S365 | 43.1 gr | 88% | 31,415 psi | 64% | 2818 fps | 95.1% |
| Vihtavuori N135 | <<locked>> | 80% | 38,203 psi | 77% | 2890 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 39,001 psi | 79% | 2894 fps | 99.5% |
| Vihtavuori N150 | <<locked>> | 80% | 31,705 psi | 64% | 2720 fps | 95.6% |
| Vihtavuori N540 | <<locked>> | 80% | 37,652 psi | 76% | 2874 fps | 99% |
| Winchester 6.5 StaBALL | <<locked>> | 86% | 34,664 psi | 70% | 2802 fps | 95.1% |
| Winchester StaBALL Match | <<locked>> | 80% | 39,885 psi | 81% | 2959 fps | 97% |
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 70 powders for .256 Mag. Gibbs loaded with the .257 | 90gr | Reichenberg HDB Universal. Alliant Power Pro 2000-MR delivers the highest muzzle velocity at 3,140 fps; across all powders the maximum-charge window runs from 2,031 fps to 3,140 fps. Accurate 3100 gives the best case fill at 100 %, and 70 of the 70 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (340 MPa), the top charges use 66–90 %, leaving at least 10 % headroom. The 90.0 gr projectile in 0.257" calls for a 1:11.0 twist; slower twists will usually not stabilise this weight. Accurate 3100, Alliant Reloder-23, Alliant Reloder-26 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 60, Alliant Reloder-17, Somchem S365 rank at the top here: for .256 Mag. Gibbs with the .257 | 90gr | Reichenberg HDB Universal they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, Accurate 2700, Accurate 3100, Alliant Reloder-26 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.