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 Θv and Θh 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 Θv and Θh are about 9° and 118°, respectively. The value of mbody was taken to be 85 lb, as before, and vbulletafter was taken to be -200 ft s-1. The values for mbullet and vbullet are described below. The equation was solved in Mathcad for vbodyafter.

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

 US Rimfire ammunition Wt, grains Rimfire veloc 30 yds, ft s-1 vlurch corner, ft s-1 22 Short 29 974.5 -0.02 22 Short Hi-Vel. 29 1063.5 -0.03 22 Short HP Hi-Vel. 27 1084.5 -0.03 22 Long Hi-Vel. 29 1157.5 -0.03 22 Long Rifle 40 1094 -0.04 22 Long Rifle 40 1069 -0.04 22 Long Rifle 40 1109.5 -0.04 22 Long Rifle Hi-Vel. 40 1248 -0.05 22 Long Rifle HP (Hi-Vel.) 37 1267.5 -0.05 22 Long Rifle HP (Hi-Vel.) 36 1267.5 -0.05 22 WRF (Rem. Spl.) 45 1348 -0.06 22 WRF Mag. 40 1817 -0.09 22 WRF Mag. 40 1817 -0.09 22 Win. Auto Inside Lub. 45 1017.5 -0.04 5 mm Rem. RFM 38 1951.5 -0.09

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

 LHO's rifle Wt, grains WCC/MC veloc 30 yd, ft s-1 vlurch corner, ft s-1 Western 6.5 MC 161 2067 -0.41

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

 Speer/DWM rifle cartridge Wt, grains German veloc 30 yds, ft s-1 vlurch corner, ft s-1 5.6x35 R Vierling 46 1871 -0.1 5.6x52 R (Savage H.P.) 71 2733 -0.26 5.6x61 SE 77 3598 -0.38 5.6x61 R 77 3378 -0.35 6.5x54 MS 159 2096.5 -0.41 6.5x57 Mauser 93 3224 -0.4 6.5x57 R 93 3224 -0.4 7x57 Mauser 103 3190.5 -0.44 7x57 Mauser 162 2693.5 -0.57 7x57 R 103 3141.5 -0.44 7x57 R 139 2457 -0.44 7x57 R 162 2623 -0.55 7x64 103 3433.4 -0.48 7x64 139 2871 -0.53 7x64 162 2852.9 -0.61 7x64 177 2815.5 -0.66 7x65 R 103 3339 -0.47 7x65 R 139 2871 -0.53 7x65 R 162 2782.9 -0.59 7x65 R 177 2754 -0.64 7 mm SE 169 3223.5 -0.74 7x75 R SE 169 3001 -0.68 30-06 180 2766.4 -0.66 8x57 JS 123 2779.3 -0.45 8x57 JS 198 2636.9 -0.68 8x57 JR 196 2271 -0.56 8x57 JRS 123 2781 -0.45 8x57 JRS 196 2378 -0.6 8x57 JRS 198 2516 -0.64 8x60 S 196 2458.1 -0.62 8x60 S 198 2681 -0.69 9.3x62 293 2453.5 -0.92 9.3x64 293 2583 -0.98 9.3x72 R 193 1827.5 -0.42 9.3x74 R 293 2300 -0.85

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

 Weatherby Magnum Wt, grains Weath veloc 30 yds, ft s-1 vlurch corner, ft s-1 224 Varmintmaster 50 3573 -0.24 224 Varmintmaster 55 3500 -0.26 240 70 3713.5 -0.36 240 90 3390.5 -0.42 240 100 3311 -0.45 257 87 3664.5 -0.44 257 100 3433.5 -0.47 257 117 3180 -0.5 270 100 3719.5 -0.51 270 130 3277.5 -0.58 270 150 3158 -0.64 7 mm 139 3208.5 -0.6 7 mm 154 3077.5 -0.64 300 150 3440 -0.7 300 180 3159.5 -0.77 300 220 2816.5 -0.82 340 200 3118.5 -0.84 340 210 3088.5 -0.87 340 250 2769 -0.91 378 270 3081 -1.12 378 300 2830.5 -1.12 460 500 2589 -1.68

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.