if it starts a 90 gr vld at 2200 fps, it's still got 450 ft lbs left at 500 yds. If it starts the more common 69 gr smk at 2500 fps, it still hits at 500 yds like a plus P 158 gr lhp does at 3m, fired from a .38 snub. Since you guys are SO sure that a .38 snub is an adequate manstopper, so is the 10" 223, at 500 yds. At 300m, the 10" 223 can easily still have 600 ft lbs. So the bozos who "think" that a 10" 223 has nothing left at 300m are fos, quite demonstrably. Even if you "only' use the 69 gr smk in the 10" barrel, it will still have450 ft lbs, considerably more power than the .45 230 gr load has at the muzzle. So the shorty 223 is going to put that 69 gr smk CLEAN thru your chest at 300m, dumbass, and you will get a pneumothorax, and you' won't be doing CRAP after 20 seconds or so. since you aint going to RUN 250 m in 20 seconds (and throw a grenade) you'll have HAD it, dumbass. In fact, ifyou TRY to run with such a wound, you'll use up all your piddly bit of remaining strength in 15 seconds, and you wont make it 100m.