2 shots in 8 or 9 seconds, slow moving target, fired by a qualified sharpshooter from 190 to 265 feet. Yeah, not too difficult.
How about with a wonky scope that no one so far has incorporated into their re-enactment? The FBI needed to add 3 shims to the scope mount just so they could hit the target, let alone thread the needle. And why would qualified sharpshooter Oswald not have sighted in the scope when he practiced his ass off, as ALL sharpshooters must do to keep sharp? Ans: because he never even fired CE 139, otherwise, he would have left at least 1 print on it that wasn't put there post-mortem.
Face it, CE 139 was the planted patsy rifle. They used it to shoot magic bullet CE 399 into a swimming pool so they could plant it on the wrong stretcher in pristine condition with no DNA on it. Yeah, not too difficult.