In developing a load for a "defend your range scenario" what is the recommended remaining energy of a projectile on a soft target? Example: 223 Rem 77gr SMK with stay supersonic till 850 yds but the remaining energy is 216 ft-lbs. We know the combat effective range is this round is 300-400 yds, yet it stays supersonic to 850 yds. I have always heard the remaining energy should 500 ft-lbs and I always used that as a guideline but since handgun round are usually below that threshold, I have a hard time sticking to that guideline. I am wondering it there is a better remaining energy number out there. Thanks Erich
