32. Scenario 1—no cloud or large fragments

    This scenario takes the simplest view of the alleged frontal shot, namely that it hit and transferred most of its rearward momentum to the head and body. It does not require the shot to have produced the snap, the explosion, the cloud, or the large fragments that shot out forward. There are serious problems with this view. If it represents a second shot impacting quickly after the first (which is sometimes acknowledged to have come from the rear) and the cloud and fragments are linked to the first shot, then most or all of the rearward lurch must be attributed to that first shot. This relegates the second shot to a much lesser importance. If the frontal shot is considered alone, then the cloud, snap, and large fragments are either linked to it or not. If they are, the forward snap cannot be produced, the timing for the snap and lurch are disallowed, and much of the time the fragments exit with too high a velocity. This is another way to say that momentum cannot be properly conserved and the explanation falls apart (next section). If those other motions are not linked to the frontal shot, then something else must be invoked to explain them. Either way, the frontal shot loses credibility. Nonetheless, we consider it alone here. It will be seen that only a few percent of the available ammunition can produce the initial lurch, and none can produce the full lurch. That ends the story of the frontal shot alone.

The procedure for calculating
    The calculational procedure resembles that for the forward snap—simple conservation of momentum. The bullet comes from the right, passes through the head, transfers some of its momentum, and pushes the head and body rearward as a unit. The equation is shown below.

where Θ_v and Θ_h are the vertical and horizontal angles from the shooter to the head. The shooter was here assumed to be at the corner of the stockade fence, for which Θ_v and Θ_h are about 9° and 118°, respectively. The value of m_body was taken to be 85 lb, as before, and v_bulletafter was taken to be -200 ft s^-1. The values for m_bullet and v_bullet are described below. The equation was solved in Mathcad for v_bodyafter.

The data on bullets and results for the lurch
    Data on 312 handgun and rifle bullets were taken from the Firearms Encyclopedia (George C. Nonte, Jr., Harper & Row, New York, 1973). The velocity at 30 yards was used, and was determined by linearly interpolating between the muzzle velocity and the velocity at 100 yards. The longer tables are given separate pages. Comments are given below each table.

U.S. rimfire ammunition

    U.S. rimfire ammunition provided the weakest rearward motions of the six sets of ammunition considered here. The movements ranged from -0.02 to -0.09 ft s^-1, far smaller than the -0.8 ft s^-1 of the initial lurch and the -2.8 ft s^-1 of the final lurch. Thus rimfire ammunition fired from the stockade fence cannot explain any part of JFK's rearward lurch.

Handgun cartridges

    The handgun cartridges are the second-weakest ammunition considered here. Their lurches ranges from -0.02 to -0.40 ft s^-1, which also cannot explain any part of JFK's rearward lurch. Notable in this group is James Files's alleged XP-100 Fireball ammunition, which creates a lurch of only -0.16 ft s^-1. This shows that somebody made up Files's story.

Mannlicher-Carcano rifle

    Could a  Mannlicher-Carcano rifle with the same type of ammunition as Oswald's have created the lurch. The answer here is a clear no, just like the rimfire and handgun cartridges considered above.

Swedish rifles

    The lurches created by Swedish rifle ammunition ranged from -0.14 to -0.95 ft s^-1. Two values out of the 58 cases (3%) exceeded the -0.8 ft s^-1 of the initial lurch and thus could have created it. None came near the final lurch of -2.8 ft s^-1, however.

German rifles

    Lurches produced by German Speer/DWM rifle cartridges ranged from -0.10 to -0.92 ft s^-1. Two of the 35 cases (6%) exceeded -0.8 ft s^-1 and so could have produced the initial lurch. None came close to the final lurch, however.

Weatherby Magnum ammunition

    Lurches from Weatherby Magnum ammunition ranged from from -0.24 to -1.68 ft s^-1. Seven of the 22 cases (32%) exceeded -0.8 ft s^-1 and so could have produced the initial lurch. As above, none came close to the final lurch, however.

American rifle cartridges

    Lurches from the American rifle cartridges ranged from from -0.12 to -1.28 ft s^-1. Eight of the 113 cases (7%) exceeded -0.8 ft s^-1 and so could have produced the initial lurch. As above, none came close to the final lurch, however.

Graphical summary of results
    The lurches produced by the 312 types of ammunition considered here are summaries by major group in the graph below. It shows the 19 cases (6%) that could have produced the initial lurch of -0.8 ft s^-1. It also shows that none of the ammunition came close to producing the final lurch of -2.8 ft s^-1. This is expected, since the final lurch accumulated over too many frames to have come from a bullet.
    The final conclusion is that only 6% of the available ammunition could have caused the initial rearward lurch, and none could have caused the full lurch. In particular, neither a Mannlicher-Carcano nor an XP-100 Fireball could have done it.
    This alone is not enough to eliminate a frontal shot. That job is done by considering it in the larger picture, as detailed at the beginning of this section. It didn't happen.

Ahead to Scenario 2—with observed cloud and large fragments
Back to Intro to Frontal Hit
Back to Physics of the Head Shot