Tschappat graduated fifth in his class from United States Military Academy at West Point, New York in 1896.

In 1898, he became a first lieutenant in the Ordnance Department and had an assignment at Watertown Arsenal, followed by an assignment in the Office of the Chief of Ordnance in Washington, D.C. Next, he spent five years at Sandy Hook Proving Ground, followed by inspection duties at the Bethlehem Steel plant in South Bethlehem, Pennsylvania.

At Picatinny Arsenal, he conducted a number of the scientific investigations in powder design and its effect upon projectiles for which he was widely recognized.

[1] In 1912, Tschappat was assigned to West Point as professor of ordnance and the science of gunnery and was promoted to lieutenant colonel during his tenure.

In addition, in 1936, the M1 Garand Semiautomatic Rifle was adopted and became the standard weapon of American infantrymen in World War II.