Editing Rifle (section)

===Barrel wear===

[[File:Benchrest mauser rifle.jpg|thumb|300px|[[Benchrest shooting]] with a Mauser rifle]]

As the bullet enters the barrel, it inserts itself into the rifling, a process that gradually wears down the barrel, and also causes the barrel to heat up more rapidly. Therefore, some [[machine gun]]s are equipped with quick-change barrels that can be swapped every few thousand rounds, or in earlier designs, were water-cooled. Unlike older carbon [[steel]] barrels, which were limited to around 1,000 shots before the extreme heat caused accuracy to fade, modern [[stainless steel]] barrels for target rifles are much more resistant to wear, allowing many thousands of rounds to be fired before accuracy drops. (Many shotguns and small arms have [[Chrome plating|chrome]]-lined barrels to reduce wear and enhance corrosion resistance. This is rare on rifles designed for extreme accuracy, as the plating process is difficult and liable to reduce the effect of the rifling.) Modern ammunition has a hardened lead core with a softer outer cladding or jacket, typically of an alloy of copper and nickel – [[cupro-nickel]]. Some ammunition is coated with [[molybdenum disulfide]] to further reduce internal friction – the so-called 'moly-coated' bullet.<ref>{{cite web|url=http://www.6mmbr.com/bulletcoating.html|title=GUIDE to Bullet Coating|website=www.6mmbr.com|access-date=2017-01-12}}</ref>