2 Verbs to Use for the Word zipping

" "One hears the zip-zip of the bullets, the boom of the great guns, the tang of our sharp French artillery, and in all this infernal experience of noise and stench, the screams of dying horses and men joined with the fury of the gun-fire, and rose shrill above it.

"Let her zip!" said the Eminent Person.

2 Verbs to Use for the Word  zipping