Editing Colt AR-15 (section)

===Sights===
The AR-15's most distinctive ergonomic feature is the carrying handle and rear sight assembly on top of the receiver. This is a by-product of the original [[ArmaLite]] design, where the carry handle served to protect the charging handle.<ref name=SAOW2>{{Cite book |last=Ezell |first=Edward Clinton |title= Small Arms of the World |year= 1983 |publisher= Stackpole Books |location=New York |isbn=978-0-88029-601-4 |pages=746–762|url=https://archive.org/details/smallarmsofworld0000ezel_12ed}}</ref> As the line of sight is {{cvt|2.5|in|1}} over the bore, the AR-15 has an inherent [[Parallax#In gunfire|parallax]] problem. At closer ranges (typically inside 15–20 meters), the shooter must compensate by aiming high to place shots where desired. The standard AR-15 rifle has a {{convert|500|mm|adj=on|2|abbr=in}} sight radius.<ref name=archive_mil>{{cite web |url=http://www.colt.com/mil/M16_2.asp |title=M16 5.56mm Rifle |access-date=2012-10-07 |url-status=dead |archive-url=https://web.archive.org/web/20110616211557/http://www.colt.com/mil/M16_2.asp |archive-date=June 16, 2011 |df=mdy-all }}. colt.com. Retrieved on 8 October 2011.</ref> The AR-15 uses an L-type flip, aperture rear sight and it is adjustable with two settings, 0 to 300 meters and 300 to 400 meters.<ref name=archive.org>{{Cite book|last=United States Government (ARMY)|url=http://archive.org/details/OperatorsManualForM16M16a1|title=Operator's Manual For M16, M16A1|language=English}}</ref> The front sight is a post adjustable for elevation. The rear sight can be adjusted for windage. The sights can be adjusted with a bullet tip or pointed tool. The AR-15 can also mount a scope on the carrying handle. With the advent of the AR-15A2, a new fully adjustable rear sight was added, allowing the rear sight to be dialed in for specific range settings between 300 and 800 meters and to allow windage adjustments without the need of a tool or cartridge.<ref name="Venola, Richard 2005">Venola, Richard (2005). "What a Long Strange Trip It's Been". Book of the AR-15 1 (2): 6–18.</ref> Current versions such as AR-15A4 have a detachable carrying handle and use [[Picatinny rail]]s, which allows for the use of various scopes and sighting devices.