Definition of "vent-plug" [vent-plug]

• Same as vent-peg, 1. (noun)
• Anything used to stop the vent of a gun while it is being sponged, the object being to insure the complete extinction of any sparks that remain from the last cartridge fired. (noun)

The Century Dictionary (Public Domain)

• "No. 1 puts in the vent-plug, wipes and lays the hammer in place and the lock-string around it, then puts on the lock-cover; sees his gun properly secured, and the implements and spare articles returned to their places."
• "The screw-thread is then to be cleaned out, and the new vent-plug screwed in."
• "One lock with string and vent-plug | complete | In place on the gun."