Oswald was qualified by the United States Marine Corps as sharpshooter.
In any case the fact remains that the killing shot came from the front. And that to duplicate his shooting job would take a rifleman with world class precision.
Think about it. Three shots were fired in about 6 seconds at a target the size of a human head. With a really bad bolt action rifle. With two hits, as far as we know. The killing head shot was fired from the front and at a low angle. Kennedy's head moved back and to the left. Now way Oswald did it. No way.