Sentence:  His soldier's instinct had him dropping to the ground before he even thought of it, and Captain Hargreaves fired his <WSD>Colt</WSD>. The bullet zoomed over Butsko's head and whacked in the chest of the hapless soldier who'd been standing behind him. Butsko rolled over on the ground, stopped, and brought his rifle quickly to his  shoulder as Captain Hargreaves fired again, his bullet burrowing in the muck six inches from Butsko's face. Butsko fired at Captain Hargreaves ... 
Meaning of the word marked with <WSD> tags:  A revolver (gun) (Colt's Manufacturing Company), associated especially but not exclusively with the American Wild West.