Using the same rifle (6.5 mm Carcano Model 91/38), marksmen have gotten off 3 shots in the time frame consistent with the audio recording on the police scanner and analysis of the Zapruder film. The time frame is always debated (from 4.8 to almost 8 seconds).
Even still, CBS did a study in the 60's with 11 marksman shooting the same model gun, and most of them hit the target with 2 of 3 shots in 5 seconds.
The other debatable issue is how many shots were fired. Blakey and the Senate Committee based much of their conclusions on the audio recordings, which suggested more than 3 shots were fired. A modern re-examination of the recording demonstrated that the 1970's analysis was flawed - they counted echos as shots. Blakey has said that it now seems clear only 3 shots were fired. Despite that, he is still on record that he believes the mob was involved.
IMO, the Mob was involved using LHO as the patsy and the shooter. I don't believe there were shots fired by anyone else (ie the grassy knoll). I do believe that Oswald slipped out of the book depository to avoid getting caught. I believe Ruby killed him to shut him up, on behalf of the mob.
I do not believe it goes beyond the mob. I don't think the CIA, Lyndon Johnson, Israel, Cuba, the Russians or anyone else was involved. For me, it is pretty simple = the Kennedy's double crossed the mob, and the mob did what they do to people who do that.
First, was the target these marksmen were shooting at moving at the same speed and at the same distance and angle as JFK's motorcade?
Second, were these marksmen considered comparable or better shots than Oswald?
Third, one has to take into account the extreme nervousness that would be present in the shooter at the moment he's taking aim at the president. I'm not sure they can really recreate that.
