From a Stephen King book if I remember rightly. His adaptations are either great or ****, and never really in between.
No one says it's impossible to shoot so many rounds in that period of time with a bolt rifle, not if they're an actual marksman. In fact, most people agree that the shots were -easy- from his range. Oswald even missed his first shot. They doubt he could do it the Italian rifle he used because they're reportedly ****. But unfortunately "I find that dubious" isn't really evidence of anything, it's just you finding something dubious. Oswald shot and missed, he the fired again, it struck JFK in the neck and bounced around the vehicle hitting the fellow passenger in this wrist. He then fired the final, fatal shot, which struck JFK in the head. Each shot was enough time between for Oswald to bolt the rifle again and take aim. It's why he DID miss the first and almost missed the second. He was going fast. Edit: Reading an article, if Oswald was actually aiming for JFKs head, the second shot was also a miss. It struck JFK but not where Oswald intended.
Think Oswald’s shooting skills are being slightly upgraded on this thread. http://22november1963.org.uk/lee-harvey-oswald-marksman-sharpshooter He had been good but his skill as a marksman had deteriorated before he even left the Marines. Very questionable as to whether he had the requisite skills by the time of the assassination.
Equally so people are greatly exaggerating the distance and difficultly of the shot. Oswald was aiming for JFKs head, missed two shots, before hitting his third. People exaggerate because he actually nailed JFK on his second attempt, but he was aiming for the head and missed. So he was close, the car was moving slowly, he had time for 3 attempts, he missed 2 out of 3 and took out his target at a third attempt. None of this is at all unbelievable, even if he was a mediocre shooter. I am an incredibly inexperienced shooter and have shot a target at a longer range than Oswald shot the president at. The Trump shooter grazed Trumps dome in his first shot and was using an assault rifle. Oswald was actually using a sniper rifle. Oswald had more experience than the Trump shooter
I've seen someone shooting a cacano rifle and they are surprisingly accurate. The were surplus Italian military. Also, he easily did the three shots in the time and he was left handed.