Under fire when this magazine is emptied you shout for “ammo” but perhaps No. 2, the ammo carrier, is lying in the rear with a bullet through his napper. Then it's “napoo-fini” (Tommy's French) for Mr. Lewis.1917, Arthur Guy Empey, “Lewis Gun”, in Over the Top, G. P. Putnam's, page 297:
'Hey, Limey,' called The Robber patiently. 'Come on out or I start using pineapples. I been expectin' you an' I got plenty ammo.'1954, Ian Fleming, “Midnight Among The Worms”, in Live and Let Die, London: Pan Books, published 1957, page 161:
2 more examples
We walked onto the racecourse like a pair of Wyatt Earps, cashed up and plenty of ammo and we walked off like a pair of Elmer Fudds, out of `buwwets'.1995, Paul Vautin, Turn It Up!, Sydney: Pan Macmillan Australia, page 110:
As with handguns and rifles, some ammos are more accurate than others.2011, Mark Brannon, Tom Hanrahan, Shooting Sporting Clays, page 39: