Yep. And actually the time between the first and third shot was estimated at 8 seconds. About 3 seconds between 1st and 2nd shot, about 5 seconds between 2nd and 3rd shot.
The Failure Analysis guys considered a few different timing scenarios, including one where a total of six seconds covered all three shots. They found even that was plausible, although working an old Carcano carbine that fast isn't the easiest thing in the world.
Oswald had qualified as a sharpshooter in the Marines (score 212, M-1 rifle, December 21, 1956). Indicating that he could, from a standing position, hit a 10-inch bullseye from a minimum of 200 yards away, 8 times out of 10.
Yup. And that's with iron sights.