Green’s Dictionary of Slang

1. (US gay) the erect penis; thus as v., to copulate aggressively .

1972		B. Rodgers Queens’ Vernacular.
1988		H. Max Gay (S)language.
2001		C. Stella Eddie’s World 10: The prick was jackhammering her ass. he pulled out, blood all over the end of his dick.

2. (N.Z. prison) a hypodermic syringe.

2001

D. Looser Boobslang [U. Canterbury D.Phil. thesis] 94/2: jackhammer a hypodermic syringe and needle).

3. a very hard punch.

2010

(con. 1973) C. Stella Johnny Porno 158: Bartosz had caught Albano [...] with a solid punch to the solar plexes, then nailed him with a jackhammer right.