4 of 4 .257 Roberts factory loads carry 800 ft·lb and expansion velocity for pronghorn; the best reach 600 yd (Nosler Trophy Grade 110 gr AccuBond). Ranked, with the drop chart for each.
| Load | gr | Max ethical yd | MV fps | 500 yd ft·lb | Shoulder shot |
|---|---|---|---|---|---|
| Nosler Trophy Grade 110 gr AccuBond | 110 | 600 | 3,050 | 970 | yes |
| Hornady Superformance 117 gr SST | 117 | 550 | 2,946 | 888 | behind the shoulder only |
| Remington 117 gr Core-Lokt Soft Point | 117 | 250 | 2,650 | 364 | behind the shoulder only |
| Winchester 117 gr Power-Point | 117 | 250 | 2,780 | 403 | behind the shoulder only |
Chuck Hawks: ~800 ft·lb at impact with a .24″+ bullet of SD ≥ .215. Legal: CO: 1,000 ft·lb at 100 yd (rifle). Floor used: 800 ft·lb at impact plus the bullet's published expansion velocity. Orange = a target or varmint bullet (construction, not energy); red = never carries the energy. Sources: www.chuckhawks.com, cpw.state.co.us.