1. Judges 3:31 (ESV)
  2. Exposition

Did he kill six hundred men at one time, like Samson with the jawbone?

Judges 3:31 (ESV)

31 After him was Shamgar the son of Anath, who killed 600 of the Philistines with an oxgoad, and he also saved Israel.

The text does not say. Perhaps he only killed a few at a time.