Dean Andrews is fascinating:
Liebeler: Do you mean to suggest by that statement that you have considerable doubt in your mind that Oswald killed the President?
Andrews: I know good and well he did not. With that weapon, he couldn't have been capable of making three controlled shots in that short time.
Liebeler: You are basing your opinion on reports that you have received over news media as to how many shots were fired in what period of time; is that correct?
Andrews: I am basing my opinion on five years as an ordnanceman in the Navy. You can lean into those things, and with throwing the bolts--if I couldn't do it myself, eight hours a day, doing this for a living, constantly on the range, I know this civilian couldn't do it. He might have been a sharp marksman at one time, but if you don't lean into that rifle and don't squeeze and control constantly, your brain can tell you how to do it, but you don't have the capability. . . .You have to stay with it. You just don't pick up a rifle or pistol or whatever weapon you are using and stay proficient with it You have to know what you are doing. You have to be a conniver. This boy could have connived the deal, but I think he is a patsy. Somebody else pulled the trigger. . . .It's just taking the five years and thinking about it a bit. I have fired as much as 40,000 rounds of ammo a day for seven days a week. You get pretty good with it as long as you keep firing. Then I have gone back after two weeks. I used to be able to take a shotgun, go on a skeet, and pop 100 out of 100. After two weeks, I could only pop 60 of them. I would have to start shooting again, same way with the rifle and machine guns. Every other person I knew, same thing happened to them. You just have to stay at it. [11H 330]
The most famous American military sniper in history, with 93 confirmed kills in Vietnam, Gunnery Sergeant Carlos Hathcock, U.S. Marine Corps senior instructor at the Sniper Instructor School at Quantico, Virginia, said his Marines had not been able to duplicate the shooting attributed to Oswald after duplicating the conditions exactly. "Now if I can't do it, how in the world could a guy who was a non-Qual on the rifle range and later only qualified 'marksman' do it?" (Craig Roberts, A Sniper Looks At Dealey Plaza, CPI, 1994, pp. 89-90.