Oswald’s Marine Booklet


I am currently reading a fascinating book called “Oswald and the CIA”, by John Newman, a must-read for JFK assassination aficionados.

On page 326 of Newman’s book, we are told that Oswald gave his Marine Corp manual to an anti-Castro and CIA connected fellow named Bringuier with the following passage highlighted:

“Sight setting: 1 minute of angle or approximately 1 inch on target for each 100 yards.”

Well clearly, this is a physics problem.  One inch divided by 100 yards is 1/3600th of a radian or approximately 1/63rd of a degree, so about 1 arcminute.  Check.

This leaves open the question of the speed of the bullet.  Using basic kinematics, and realizing the bullet drops 1 inch as it horizontally travels 100 yards, and using the approximation of g = 32 ft/sec squared, I found a horizontal speed of 4157 ft/sec, which is an incredible Mach 3.7.

I found this speed to be unbelievable, but sure enough there was a bullet commercially available as early as 1935 from Winchester, called the .220 Swift, with a muzzle speed of approximately 4100 ft/sec!

By the way, the reason why Oswald couldn’t drive a car was not because he had bad eyesight.  It was because he could not get a driver’s license, due to his dishonorable discharge from the Marine Corps.

And yes, I did see Ruby shoot Oswald on live TV as a kid.


Author: Bob Mahoney

Physics teacher

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