19 of 19 .375 H&H Mag factory loads carry 1,000 ft·lb and expansion velocity for whitetail deer; the best reach 750 yd (Hornady Dangerous Game Series 270 gr SP-RP InterLock). Ranked, with the drop chart for each.
The 1,000 ft·lb deer figure traces to Townsend Whelen and is the one everyone repeats; Hawks puts the floor nearer 800. An 8–10″ heart/lung zone. Legal: CO: 1,000 ft·lb at 100 yd · SD: 1,000 ft·lb at muzzle. Floor used: 1,000 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.outdoorlife.com, www.petersenshunting.com, chuckhawks.com.