What did Jensen do with a pistol? What did lee strunk admit to taking?

From the text:

Jensen broke his own nose with a pistol.

Because late that same night he borrowed a pistol, gripped it by the barrel, and used it like a hammer to break his own nose.

Strunk stole his Jensen's jackknife.

But in the morning Lee Strunk couldn't stop laughing. "The man's crazy," he said. "I stole his fucking jackknife."