If the Duchamp urinal is art, then anything is. But there has to be consensus about good art among informed people -- artists, dealers, curators, collectors. Somebody has to be the first to say something is good, but if you put it up the flagpole and nobody salutes it, then there's nothing there. WILLIAM RUBIN
Conventional eight groove rifling on the left, and octagonal rifling on the right. Polygonal rifling /pÉËlÉªÉ¡ÉnÉl/ 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 taking the form of a hexagon or octagon.n the Glock pistol, for instance, octagonal rifling is used in the large diameter .45 ACP bore, which has an 11.23 mm (0.442 in) diameter, since it resembles a circle more closely than the hexagonal rifling used in smaller diameter bores.
'Rifling' is grooves in a barrel which grip and spin the projectile, like this cut-away of the venerable L7 105mm shows: This is the classic rifling method, called 'land and groove'.However, there are different types of rifling, including one called 'polygonal rifling', which has undulations in the inside of the barrel with hills and valleys, instead of sharp-edged lands and grooves:Illustrating the differences with a schematic:n small arms bullets, where you actually deform the entire projectile, polygonal rifling is supposed to give a sightly better gas seal and slightly lower friction. For large-caliber systems, the driving band system offers less deformation of material, and therefore less wear.