Polygonal rifling ( /pəˈlɪɡənəl/) is a type of gun barrel rifling where the traditional lands and grooves are replaced by "hills and valleys" in a rounded polygonal pattern, usually a hexagon or octagon.
Polygons with a larger number of edges provide a better gas seal in relatively large diameter polygonally rifled bores. In the Glock pistol, for instance, octagonal rifling is used in the large diameter .45 ACP bore, which has a 11.23 mm (0.442 in) diameter, since it resembles a circle more closely than the hexagonal rifling used in smaller diameter bores.
Read more about Polygonal Rifling: History, Advantages, Forensic Firearms Examination, Lead Bullets and Polygonal Rifling
Famous quotes containing the word rifling:
“Always polite, fastidiously dressed in a linen duster and mask, he used to leave behind facetious rhymes signed “Black Bart, Po—8,” in mail and express boxes after he had finished rifling them.”
—For the State of California, U.S. public relief program (1935-1943)