Warning: Bullet selections are specific, and loads are not valid with substitutions of different bullets of the same weight. Variations in bullet length will alter net case capacity, pressure and velocity. Primer selection is specific and primer types are not interchangeable. These are maximum loads in my firearms and may be excessive in others. All loads should be reduced by 5% as a starting point for development where cartridges have greater than 40 grains in capacity and 10% for cartridges with less than 40 grain capacity following safe handloading practices as represented in established mainstream reloading manuals. Presentation of these loads does not constitute a solicitation for their use, nor a recommendation.
Cartridge |
257 Roberts +P |
Firearm | Ruger No.1 |
Barrel Length | 20″ |
Min – Max Case Length | 2.233″ +0.0″/-0.020″ |
Min – Max Cartridge Overall Length | 2.620″ – 2.780″ |
Primer | CCI 200 – Large Rifle |
Bullet Diameter | 0.258″ +0.0″/-0.003″ |
Reloading Dies | Lee Precision |
Bullet Type | Bullet Weight Grains |
Net H2O Grains Capacity |
COL” | Powder Type | Powder Charge Grains |
Muzzle Velocity fps |
Muzzle Energy ft/lbs |
Hornady FP | 60 | 53.2 | 2.535 | 2400 | 15.0 | 2163 | 623 |
Hornady FP | 60 | 53.2 | 2.535 | TrailBoss | 11.0 | 1899 | 481 |
Hornady FP | 60 | 53.2 | 2.535 | Varget | 47.0 | 3686 | 1811 |
Sierra Varminter | 75 | 47.0 | 2.700 | IMR4064 |
44.0 | 3481 | 2018 |
Sierra Varminter | 75 | 47.0 | 2.700 | H414 | 51.0 | 3521 | 2065 |
Sierra Varminter | 75 | 47.0 | 2.700 | Win 760 |
50.0 | 3517 | 2060 |
Barnes TSXFB | 115 | 47.3 | 2.780 | Re 19 | 46.0 | 2768 |
1957 |
Barnes TSXFB | 115 | 47.3 | 2.780 | Hybrid 100V |
46.0 | 2832 | 2049 |
Barnes TSXFB | 115 | 47.3 | 2.780 | Norma MRP | 47.0 | 2824 | 2037 |
Sierra SP | 117 | 49.1 | 2.775 | Re 17 | 43.5 | 2811 | 2053 |
Sierra SP | 117 | 49.1 | 2.775 | IMR 7828 SSC |
48.0 | 2830 | 2081 |
Sierra SP | 117 | 49.1 | 2.775 | Norma MRP | 48.0 | 2813 | 2056 |
Hornady BTSP | 117 | 48.7 | 2.780 | Re 17 | 44.0 | 2819 | 2065 |
Hornady BTSP | 117 | 48.7 | 2.780 | IMR 4831 | 46.0 | 2795 | 2030 |
Hornady BTSP | 117 | 48.7 | 2.780 | Norma 204 | 45.0 | 2796 | 2031 |
Nosler Partition | 120 | 47.8 | 2.750 | IMR 4350 | 44.0 | 2799 | 2088 |
Nosler Partition | 120 | 47.8 | 2.750 | IMR 7828SSC | 47.0 | 2792 | 2078 |
Nosler Partition | 120 | 47.8 | 2.750 | Norma MRP | 47.5 | 2771 | 2046 |
Speer SPBT |
120 |
48.6 |
2.770 |
Re19 | 46.0 | 2794 | 2081 |
Speer SPBT | 120 | 48.6 | 2.770 | IMR 4831 | 45.5 | 2800 | 2091 |
Speer SPBT | 120 | 48.6 | 2.770 |
Norma MRP | 45.5 | 2787 | 2070 |
Speer Grand Slam | 120 | 48.9 | 2.780 | Re19 | 46.0 | 2798 | 2087 |
Speer Grand Slam | 120 | 48.9 | 2.780 | IMR 4831 | 44.5 | 2762 | 2033 |
Speer Grand Slam | 120 | 48.9 | 2.780 | IMR7828SSC | 47.0 | 2759 | 2029 |
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