Editing M16 rifle (section)

===Mk 12 Special Purpose Rifle===
{{Main|Mk 12 Special Purpose Rifle}}
[[File:SPRCrane.jpg|thumb|US Navy Mk 12 Special Purpose Rifle]]

Developed to increase the effective range of soldiers in the designated marksman role, the U.S. Navy developed the Mk 12 Special Purpose Rifle (SPR). Configurations in service vary, but the core of the Mk 12 SPR is an 18" heavy barrel with muzzle brake and free float tube. This tube relieves pressure on the barrel caused by standard handguards and greatly increases the potential accuracy of the system. Also common are higher magnification optics ranging from the 6× power Trijicon ACOG to the Leupold Mark 4 Tactical rifle scopes. Firing Mk 262 Mod 0 ammunition with a 77gr Open tip Match bullet, the system has an official effective range of 600+ meters. However, published reports of confirmed kills beyond 800&nbsp;m from Iraq and Afghanistan were not uncommon.{{Citation needed|date=May 2010}}