[elhombrelibre]

We know the round recovered is a .223 Remington or as the military says 5.56 mm. I didn't go to the Russian web site, so I don't know if they even made this bullet. I believe the lethality of a .223 isn't very good at modest ranges let alone at a mile. I'd say the effectiveness so far is largely do to well-placed shots on unsuspecting targets. In other words, a .22 caliber long rifle could do that at the right ranges. That's my two cents.

[Francohio]

According to SOF, which is rarely wrong on these matters, sniper versions of the 5.56 are shooting with sub-MOA accuracy at 700 meters in Afghanistan.

The report went on to state that the hits at extreme ranges with the sniper versions of the 5.56 are not always as lethal as the snipers might wish, but reliably on target.

Scoped varmint rifles chambered for the old 220 Swift, 222 Remington, etc. which are not that different than the 5.56, were reliably accurate on varmints at 500 yards. The right 5.56 rifle, in trained hands, may therefore be quite capable of inflicting the damage seen in the DC attacks. We also don't know the range of the shots. It's possible the guy is only 150 yards away. That's a long way off in a suburban environment with lots of trees, buildings, and cars to break the line of sight and bounce the sound around.

I also think it possible that a single, unsupported shooter could be responsible. Only one shot is being fired per attack, so there is no need for a spotter. If it is a team, the other guy is the driver.