The simple fact of the matter is that no one has ever truly duplicated Oswald's alleged shooting feat of 2/3 in 6 seconds. The only way to expand the firing time is to assume that he missed the first shot, the closest and easiest shot.
The only test that involved the alleged murder rifle itself is very revealing.
The WC hired three Master-rated riflemen to attempt to duplicate Oswald's alleged shooting feat. The three Master-rated shooters who participated in that test fired 18 rounds while using the scope and three rounds while using the iron sights. They used the alleged murder weapon, the Mannlicher-Carcano that was traced to Lee Harvey Oswald. Tellingly, they missed the head and neck area of the target board silhouettes 18 out of 18 times when they used the scope, and 2 out of 3 times when they used the iron sights. In other words, they missed the head and neck area of the target silhouettes 20 out of 21 times. Several of their misses were far apart on the boards. Some of their shots missed the silhouettes entirely. It's revealing that they shot so poorly even though they were allowed to take as long as they wanted for the first shot, even though two of them took longer than 6 seconds to fire, even though they were only firing from 30 feet up, and even though they were shooting at stationary--yes, stationary--target boards.
The three riflemen in the test were named Miller, Hendrix, and Staley. (Their first names were never given.) In the first series, Miller took 4.6 seconds to fire three shots, Staley took 6.75 seconds, and Hendrix took 8.25 seconds. In the next series, Miller took 5.15 seconds, Staley took 6.45 seconds, and Hendrix took 7 seconds. It bears repeating that Oswald would have had only one attempt, only one series. Oswald supposedly scored two hits out of three shots, yet Miller, Hendrix, and Staley—all Master-rated riflemen—missed the head and neck area of the target silhouettes 20 out of 21 times.