Gibbs is competent with a rifle

Gibbs aimed down the sights, and the rifle kicked against his shoulder. An ex sprayed its brains behind it and toppled over. He re-aimed, fired, and the dead woman stumbled at the last instant. His round tore a wide strip of the ex’s scalp away and knocked its head to the side, but it kept plodding forward.

Excerpt From Ex-Isle, pg 550
Peter Clines
https://books.apple.com/us/book/ex-isle/id989619017