JFK Assassination Forum

You don't think all those other spectators would see a shooter on the overpass or hear his gunshot?

Do conspiracy hobbyists ever think through their theories?

The survey data at CE884 puts the Kennedy to Rifle distance 218.0 feet at z255 and 265.3 feet at z313. That means that he travelled 47.3 feet in 58 frames. At that rate at z271 JBC was 233 feet from the rifle. At 2000 fps that means the trigger was pressed about 233/2000=116.5 ms earlier.

For the shot that struck at z313 when JFK was 265.3 feet from the rifle, the trigger would have been pulled 265.3/2000=133 ms earlier.

So we are talking about a difference of 16.5 ms or .0165 of a second

Since the exposure time of Zapruder’s camera was 1/40th of a second or 25 ms., there was 30 ms of non-exposure between frames.

When I say z271-272 I mean the shot occurred at some time either very late during the exposure of z270 up to very early in the beginning of the exposure of z272.  Since the time between frames is 1000/18.3=55 ms, that provides a range of the time of the shot of 55+30=85 ms. The head shot could have occurred very late in the exposure of z312 to the middle of the exposure of z313.  That is about 45 ms. Total uncertainty is 130/2=65 ms=.065 sec.

So the time difference t between trigger pulls between the second shot striking JBC at z271-272 and the third shot striking JFK at z312 to z313 a distance of 32.3 feet farther from the rifle is:
t=(312-270)/18.3-(32.3/2000)  ± .065 seconds

t=(42)/18.3-.0165 ± .065 seconds

t=2.28  ± .065 seconds or 2.22 to 2.34 seconds

Certainly. Hickey just said that JFK’s hair flew up at the moment he heard the second shot. There could have been movement of the air caused by something other than the bullet.  But that wouldn’t alter the observation that the hair flutter-which occurs at no other time-coincided with the sound of the second shot.  But I don’t see the hair of anyone else move.

The Warren Commission found that a minimum of about 2.3 seconds was required to fire, reload aim and fire again using Oswald’s rifle. This appears to be based on the FBI re-enactment using that rifle. FBI ballistics expert Robert Frazier, who actually fired 3
shots in 4.6 seconds, said “4.6 seconds is firing this weapon as fast as the bolt can be operated, I think”. (3H407). The FBI’s Ronald Simmons noted that one marksman fired three shots in 4.6 seconds using the telescopic sight and three shots in 4.45 seconds using the iron sights.(3H446). There was no time placed on the middle shots so we cannot determine the smallest interval between shots.

The head shot would have to have been fired at Z311 or earlier to cover the 88 yards before striking JFK's head at Z313. That is based on an estimated average velocity of 2000 fps.
88 yards is 264 feet.
264 / 2000 = 0.132 seconds to cover the 88 yards.
1 / 18.3 = 0.546.... elapsed time for a single frame.
0.132 / 0.546... = 2.4156 frames for the bullet to travel 88 yards

I don't suppose you considered the possibility that JFK's hair movement could be cause by the fact he is in a moving open top car.

Oswald could have fired a shot 2.3 seconds after a previous shot as long as he didn't bother to take time to aim the rifle. The FBI determined it would take a shooter a minimum of 2.4 seconds between shots if the shooter took time to aim.