Target: adult book title

["Rebecca S. Dann" <rdann@DOE.STATE.IN.US>]

A friend has asked me to ask you all if any of you remember a book he read
several times in the late 80s and now cannot remember the title or author.
If we can locate it he wishes to buy it if it is still in print. Here is
the basic scenario:
        The main character is a marksman who studies arms and targeting.
He thinks he is hired by the government to calculate trajectory and
accuracy of new weapons. He does an in depth study of a particular weapon
which is then used in an assassination. Of course he is arrested and most
of the book is court room stuff. He is in the end proven innocent because
the real assassin suspected a setup and did something to the weapon so
that it wouldn't shoot. Sounds vaguely familiar to me but too many years
ago for me to recall. Any help would be greatly appreciated. E-mail me
personally please, to address below.

Rebecca Dann
Adams Central Community Schools
222 West Washington
Monroe, Indiana  46772
rdann@ideanet.doe.state.in.us