'(<a href="http://www.j-archive.com/media/2002-09-05_DJ_02.jpg" target="_blank">Cheryl of the Clue Crew reports from FBI Headquarters in Washington.</a>)  Known as this, the grooves cut into the barrel help investigators match a bullet to a gun'
the rifling
STARTS WITH R: Known as this, the grooves cut into the barrel help investigators match a bullet to a gun
Known as this, the grooves cut into the barrel help investigators match a bullet to a gun
Known as this, the grooves cut into the barrel help investigators match a bullet to a gun
STARTS WITH "R"
the rifling
STARTS WITH "R"