Load Specifications
Load data in caliber .257 Roberts with .257 | 100gr | Nosler Ballistic Tip Hunting bullet and 56 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are ReloadSwiss RS 60 and ReloadSwiss RS 70.
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% | 46,050 psi | 89% | 2877 fps | 100% |
| Accurate 4064 | <<locked>> | 86% | 46,238 psi | 90% | 2923 fps | 100% |
| Accurate 4350 | <<locked>> | 94% | 45,237 psi | 88% | 2972 fps | 97.6% |
| ADI AR 2208 | <<locked>> | 86% | 45,020 psi | 87% | 2887 fps | 98% |
| Alliant Power Pro 2000-MR | <<locked>> | 84% | 45,788 psi | 89% | 3038 fps | 98.1% |
| Alliant Reloder- TS 15.5 | <<locked>> | 86% | 44,614 psi | 87% | 2913 fps | 99.1% |
| Alliant Reloder-15 | <<locked>> | 84% | 44,976 psi | 87% | 2923 fps | 98.1% |
| Alliant Reloder-16 | <<locked>> | 94% | 44,222 psi | 86% | 2979 fps | 97.6% |
| Alliant Reloder-17 | <<locked>> | 90% | 44,701 psi | 87% | 3015 fps | 99.1% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 38,029 psi | 74% | 2858 fps | 97.4% |
| Alliant Reloder-26ᴾ | <<locked>> | 100% | 42,453 psi | 82% | 3018 fps | 96.4% |
| Baschieri & Pellagri 107 | <<locked>> | 82% | 46,108 psi | 90% | 2943 fps | 97.9% |
| Bofors RP3 | <<locked>> | 86% | 44,657 psi | 87% | 2920 fps | 99.2% |
| Hodgdon H380 | <<locked>> | 86% | 45,498 psi | 88% | 2923 fps | 97.1% |
| Hodgdon Hybrid 100V | <<locked>> | 98% | 46,325 psi | 90% | 2969 fps | 99.2% |
| Hodgdon LEVERevolution | <<locked>> | 84% | 46,238 psi | 90% | 2982 fps | 99.4% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 35,331 psi | 69% | 1906 fps | 100% |
| Hodgdon VARGET | <<locked>> | 82% | 45,382 psi | 88% | 2904 fps | 99% |
| IMR 4064 | <<locked>> | 84% | 44,483 psi | 86% | 2871 fps | 98.1% |
| IMR 4831 | <<locked>> | 96% | 46,093 psi | 90% | 2969 fps | 97.9% |
| IMR 4895 | <<locked>> | 84% | 46,093 psi | 90% | 2959 fps | 98.8% |
| Lovex D073.6 | <<locked>> | 82% | 45,745 psi | 89% | 2917 fps | 100% |
| Lovex S060 | <<locked>> | 82% | 46,528 psi | 90% | 2871 fps | 98.8% |
| Lovex S062 | <<locked>> | 84% | 44,063 psi | 86% | 2867 fps | 99.3% |
| Lovex S065 | <<locked>> | 92% | 46,485 psi | 90% | 2913 fps | 96.5% |
| Norma 201 | <<locked>> | 82% | 45,556 psi | 88% | 2887 fps | 99.4% |
| Norma 202 | <<locked>> | 82% | 46,151 psi | 90% | 2900 fps | 100% |
| Norma 203B | <<locked>> | 84% | 44,266 psi | 86% | 2910 fps | 98.5% |
| Norma URP | <<locked>> | 94% | 44,904 psi | 87% | 2966 fps | 97.4% |
| Ramshot Big Game | <<locked>> | 84% | 44,251 psi | 86% | 2930 fps | 98.3% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 35,752 psi | 69% | 1949 fps | 100% |
| ReloadSwiss RS 52 | <<locked>> | 82% | 44,440 psi | 86% | 2979 fps | 98% |
| ReloadSwiss RS 60 | <<locked>> | 88% | 44,440 psi | 86% | 3022 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 94% | 44,976 psi | 87% | 2992 fps | 97.3% |
| ReloadSwiss RS 70 | <<locked>> | 94% | 44,947 psi | 87% | 3005 fps | 96.6% |
| Rottweil R 902 | <<locked>> | 84% | 46,224 psi | 90% | 2890 fps | 99.5% |
| Rottweil R 903 | <<locked>> | 88% | 44,541 psi | 87% | 2910 fps | 99% |
| Shooters World Long Rifle | <<locked>> | 92% | 46,485 psi | 90% | 2913 fps | 96.5% |
| Shooters World Match Rifle | <<locked>> | 82% | 45,745 psi | 89% | 2917 fps | 100% |
| Shooters World Precision | <<locked>> | 84% | 44,063 psi | 86% | 2867 fps | 99.3% |
| SNPE Vectan SP 11 | <<locked>> | 88% | 45,977 psi | 89% | 2969 fps | 98.7% |
| SNPE Vectan SP 9 | <<locked>> | 82% | 45,107 psi | 88% | 2904 fps | 98.6% |
| SNPE Vectan Tubal 5000 | <<locked>> | 86% | 44,527 psi | 86% | 2799 fps | 100% |
| Somchem S335 | <<locked>> | 82% | 46,528 psi | 90% | 2841 fps | 100% |
| Somchem S355 | <<locked>> | 88% | 45,353 psi | 88% | 2917 fps | 99% |
| Somchem S365 | <<locked>> | 98% | 45,948 psi | 89% | 3028 fps | 99.9% |
| Vihtavuori N135 | <<locked>> | 84% | 45,730 psi | 89% | 2874 fps | 100% |
| Vihtavuori N140 | <<locked>> | 84% | 46,528 psi | 90% | 2884 fps | 100% |
| Vihtavuori N150 | <<locked>> | 90% | 46,166 psi | 90% | 2897 fps | 99.8% |
| Vihtavuori N160 | <<locked>> | 92% | 43,976 psi | 85% | 2907 fps | 97.1% |
| Vihtavuori N540 | <<locked>> | 84% | 44,991 psi | 87% | 2871 fps | 100% |
| Vihtavuori N550 | <<locked>> | 94% | 46,282 psi | 90% | 2969 fps | 97.5% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 41,379 psi | 80% | 2943 fps | 97.4% |
| Winchester 6.5 StaBALL | <<locked>> | 92% | 44,353 psi | 86% | 2890 fps | 99% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 34,229 psi | 66% | 2835 fps | 96.6% |
| Winchester StaBALL Match | <<locked>> | 82% | 44,875 psi | 87% | 2913 fps | 99% |
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% | 40,132 psi | 78% | 2772 fps | 100% |
| Accurate 4064 | <<locked>> | 80% | 37,956 psi | 74% | 2759 fps | 99.8% |
| Accurate 4350 | <<locked>> | 88% | 36,651 psi | 71% | 2785 fps | 95.1% |
| ADI AR 2208 | <<locked>> | 80% | 37,362 psi | 73% | 2720 fps | 96% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 39,842 psi | 77% | 2900 fps | 96.5% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 36,695 psi | 71% | 2736 fps | 97.5% |
| Alliant Reloder-15 | <<locked>> | 80% | 39,421 psi | 77% | 2805 fps | 96.8% |
| Alliant Reloder-16 | <<locked>> | 88% | 36,767 psi | 71% | 2795 fps | 95.1% |
| Alliant Reloder-17 | <<locked>> | 82% | 33,895 psi | 66% | 2749 fps | 95.9% |
| Alliant Reloder-23 | <<locked>> | 96% | 33,634 psi | 65% | 2740 fps | 95.6% |
| Alliant Reloder-26 | <<locked>> | 98% | 39,581 psi | 77% | 2946 fps | 95.3% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 43,076 psi | 84% | 2881 fps | 97.2% |
| Bofors RP3 | <<locked>> | 80% | 36,535 psi | 71% | 2743 fps | 97.5% |
| Hodgdon H380 | <<locked>> | 82% | 39,871 psi | 77% | 2802 fps | 95.5% |
| Hodgdon Hybrid 100V | <<locked>> | 86% | 31,589 psi | 61% | 2625 fps | 95% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 40,118 psi | 78% | 2858 fps | 98.4% |
| Hodgdon TrailBoss | <<locked>> | 80% | 26,382 psi | 51% | 1706 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 42,337 psi | 82% | 2841 fps | 98.4% |
| IMR 4064 | <<locked>> | 80% | 39,218 psi | 76% | 2756 fps | 96.8% |
| IMR 4831 | <<locked>> | 90% | 37,768 psi | 73% | 2795 fps | 95.6% |
| IMR 4895 | <<locked>> | 80% | 40,364 psi | 78% | 2838 fps | 97.6% |
| Lovex D073.6 | <<locked>> | 80% | 42,946 psi | 83% | 2861 fps | 99.8% |
| Lovex S060 | <<locked>> | 80% | 43,816 psi | 85% | 2815 fps | 98.4% |
| Lovex S062 | <<locked>> | 80% | 38,885 psi | 76% | 2759 fps | 98.4% |
| Lovex S065 | <<locked>> | 90% | 43,714 psi | 85% | 2858 fps | 95.7% |
| Norma 201 | <<locked>> | 80% | 42,815 psi | 83% | 2831 fps | 99.1% |
| Norma 202 | <<locked>> | 80% | 43,033 psi | 84% | 2844 fps | 100% |
| Norma 203B | <<locked>> | 80% | 38,798 psi | 75% | 2792 fps | 97.2% |
| Norma URP | <<locked>> | 90% | 39,262 psi | 76% | 2844 fps | 95.8% |
| Ramshot Big Game | <<locked>> | 80% | 38,537 psi | 75% | 2805 fps | 96.9% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 26,585 psi | 52% | 1745 fps | 100% |
| ReloadSwiss RS 52 | <<locked>> | 80% | 41,553 psi | 81% | 2917 fps | 97.3% |
| ReloadSwiss RS 60 | 39.1 gr | 80% | 33,924 psi | 66% | 2766 fps | 98.4% |
| ReloadSwiss RS 62 | <<locked>> | 90% | 39,001 psi | 76% | 2864 fps | 95.5% |
| ReloadSwiss RS 70 | 45.6 gr | 92% | 41,930 psi | 81% | 2933 fps | 95.6% |
| Rottweil R 902 | <<locked>> | 80% | 40,814 psi | 79% | 2782 fps | 98.7% |
| Rottweil R 903 | <<locked>> | 80% | 34,127 psi | 66% | 2677 fps | 96.5% |
| Shooters World Long Rifle | <<locked>> | 90% | 43,714 psi | 85% | 2858 fps | 95.7% |
| Shooters World Match Rifle | <<locked>> | 80% | 42,946 psi | 83% | 2861 fps | 99.8% |
| Shooters World Precision | <<locked>> | 80% | 38,885 psi | 76% | 2759 fps | 98.4% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 35,288 psi | 69% | 2730 fps | 95.9% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 42,438 psi | 82% | 2848 fps | 98% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 36,709 psi | 71% | 2641 fps | 99.9% |
| Somchem S335 | <<locked>> | 80% | 43,772 psi | 85% | 2789 fps | 100% |
| Somchem S355 | <<locked>> | 80% | 35,027 psi | 68% | 2687 fps | 96.5% |
| Somchem S365 | <<locked>> | 84% | 28,950 psi | 56% | 2608 fps | 95.3% |
| Vihtavuori N135 | <<locked>> | 80% | 40,103 psi | 78% | 2769 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 40,756 psi | 79% | 2772 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 33,257 psi | 65% | 2618 fps | 97.4% |
| Vihtavuori N160 | <<locked>> | 88% | 38,667 psi | 75% | 2792 fps | 95.5% |
| Vihtavuori N540 | <<locked>> | 80% | 39,523 psi | 77% | 2762 fps | 99.7% |
| Vihtavuori N550 | <<locked>> | 88% | 38,101 psi | 74% | 2792 fps | 95.1% |
| Vihtavuori N555 | <<locked>> | 96% | 36,274 psi | 70% | 2822 fps | 95.8% |
| Winchester 6.5 StaBALL | <<locked>> | 82% | 31,807 psi | 62% | 2592 fps | 95.2% |
| Winchester StaBALL HD | <<locked>> | 98% | 31,981 psi | 62% | 2759 fps | 95.1% |
| Winchester StaBALL Match | <<locked>> | 80% | 41,858 psi | 81% | 2851 fps | 98.4% |
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 56 powders for .257 Roberts loaded with the .257 | 100gr | Nosler Ballistic Tip Hunting. Alliant Power Pro 2000-MR delivers the highest muzzle velocity at 3,038 fps; across all powders the maximum-charge window runs from 1,906 fps to 3,038 fps. Alliant Reloder-23 gives the best case fill at 100 %, and 56 of the 56 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (355 MPa), the top charges use 66–90 %, leaving at least 10 % headroom. The 100.0 gr projectile in 0.257" calls for a 1:10.0 twist; slower twists will usually not stabilise this weight. Alliant Reloder-23, Alliant Reloder-26, Hodgdon TrailBoss 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. IMR 4350, ReloadSwiss RS 60, ReloadSwiss RS 70 rank at the top here: for .257 Roberts with the .257 | 100gr | Nosler Ballistic Tip Hunting 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.