Search results
Results From The WOW.Com Content Network
Machining the rifling grooves texture on a thin metal plate, then folding the plate into the inner bore of the barrel (liner rifling) The grooves are the spaces that are cut out, and the resulting ridges are called lands. These lands and grooves can vary in number, depth, shape, direction of twist (right or left), and twist rate.
Conventional eight groove rifling on the left, and octagonal polygonal rifling on the right. Polygonal rifling (/ p ə ˈ l ɪ ɡ ə n əl / pə-LIG-ə-nəl) is a type of gun barrel rifling where the traditional sharp-edged "lands and grooves" are replaced by less pronounced "hills and valleys", so the barrel bore has a polygonal (usually hexagonal or octagonal) cross-sectional profile.
A rifled bore consists of alternating grooves and lands. The distance across the bore from groove to groove is greater than the distance from land to land. Projectiles fired from rifled barrels must be of the full groove-to-groove diameter to be effectively rotated by the rifling, but the caliber has sometimes been specified as the land-to-land ...
The lands and grooves of barrel are the bumps and valleys created when the rifling is created. The caliber is the diameter of the barrel. The caliber is the diameter of the barrel. The twist is the direction of the striations left by the barrel's rifling, clockwise (right-handed) or counterclockwise (left-handed).
The .308 Winchester is measured across the grooves and uses a .308-in diameter (7.82-mm) bullet; the military-specification version is known as 7.62 × 51 mm NATO, so called because the bore diameter measured between the lands is 7.62 mm, and the cartridge has a case 51 mm long. [5]
Gradually, rifles appeared with cylindrical barrels cut with helical grooves, the surfaces between the grooves being "lands". The innovation was shortly followed by the mass adoption of breech-loading weapons, as it was not practical to push an overbore bullet down through a rifled barrel. The dirt and grime from prior shots were pushed down ...
Checked Out. Countless grocery store chains have come and gone over the years, many that were household names at one point in time. With competition from upstarts, razor thin profit margins, and ...
These grooves and their counterpart, called "lands" imprint groove and land impressions on the surface of the bullet. Together with these land and groove impressions, imperfections on the barrel surface are incidentally transferred to the bullet's surface. Because these imperfections are randomly generated, during manufacture or due to use ...