This is becoming a complex discussion. Apparently AR-15's vary in barrel twist [1 in 7, 1 in 9, 1 in 12, and 1 in 16 at least], performance with different grades of .223 or 22LR ammunitiion [more expensive genreally more accurate], and on and on.

Various internet sources and forum contributors differ on whether .223 shot from AR-15s tumble and so damage larger parts of what the slug hits. Ditto with the effectiveness of the AR-15 .223 as a one shot, one kill deer rifle.

At the moment in my researches, it seems all concur that the accuracy of 22LR fired through and AR-15 .223 barrel is not great and probably not appropriate for hunting at any distance.

More research!