I don't know guns but I understand Physics. The shot has left the barrel. Any reactive force would already be evident in Obamas shoulder or facial expression as he reacts to the blast
Obama does not even flinch. The gun obviously has VERY little kickback and the rightwing posters on this thread are full of shit
Or more likely it has no kickback and it not a "real" pic.
Thus the odd gas patterns.
Background sure doesnt scream shooting range.