1 of 1 .275 Rigby factory loads carry 800 ft·lb and expansion velocity for pronghorn; the best reach 500 yd (Hornady Custom 140 gr SP InterLock). Ranked, with the drop chart for each.
| Load | gr | Max ethical yd | MV fps | 500 yd ft·lb | Shoulder shot |
|---|---|---|---|---|---|
| Hornady Custom 140 gr SP InterLock | 140 | 500 | 2,680 | 850 | 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.