TriggerTalk August 2018 Courant Article – AR15 Accessory Rails
When first designed by Eugen Stoner the Armalite Rifle was a fairly simple lightweight design wonder. Quickly identified by the solid polymer stock and triangular shaped forestock (also known as a forearm or handguard) and built in carry handle.
The desire to mount optics on the AR15 and M16 to take advantage of the accuracy and long range potential of the AR15 led to a removable carry handle that was integral with the upper receiver on prior models. On top of the receiver is a very precise rail is used both to mount the removable handle as well as optics mounts. The rail is designed to a specific set of dimension and was dubbed the M1913 Picatinny Rail named after the Military Arsenal in Picatinny, New Jersey where testing took place.
The Military Standard design ensures that equipment designed for it will indeed fit and when properly matched to the mount will allow the removal and reinstallation of equipment that retains the zero settings and accuracy of the remounted optic.
On the AR15 this led to the birth of an entire industry, the original and most common being called a “Quad Rail”. This beautiful piece of machined metal takes the place of the standard forestock and replaces it with the a four sided handguard with a Picatinny rail that matches the receiver on top and adds rails to each side and bottom.
Over the past 23 years the Picatinny rail has been used on many rifles as original equipment or added via the forestock or other mechanical attachments. The list of things that can be mounted is virtually endless. Owners quickly realized that when mounting a scope low on the rifle, the original A2 front sight was visible in the center of the scope, so people removed the combination gas block and sight and aftermarket folding front and rear sights were born.
Vertical or angled fore grips were added to provide a more comfortable hand position and bipods were often added to the bottom rail for steady long range shooting.
Far beyond the Picatinny rail there are proprietary systems such as M-Lok and others may or may not be compatible with your existing equipment. At a recent Shot Show I observed three separate areas with thousands of square feet dedicated to these add-on accessories
I you embark down this path, do not forget that the original purpose for the forestock was twofold: 1st provide a comfortable convenient place to hold on to the gun, and 2nd to insulate the shooters hand from the heat generated in the barrel from firing the gun.
Today’s rails allow for hand grips, optics mounts. back-up 45 degree sights, bright weapons lights with pressure activated switch as well as other devices all add up to a lot of weight Be sure to be practical when equipping your gun!