A full length quad rail, especially on an AR, lets you mount anything you need almost any place you need. As a result we have a ton of quad rail handguards like the CAA-Tactical Handguard w/Picatinny Quadrail Set for the AK or the BLACKHAWK AR15 Carbine Length 2Pc Quad Rail that doesn’t even feel the need to tell you it’s a Picatinny rail system. Having one uniform system is a great advantage because all of your accessories can be mounted anywhere you have a rail. For the most part, few people will need to worry about this because if you are buying any tactical rails or accessories they will be Picatinny. 206 inches wide on a MIL-STD-1913 (Picatinny) rail and only. The easiest way to tell them apart is that the grooves that hold things in place are. It is important to now which rail system you have and what accessories you own designed for it. CAA Tactical Handguard with Picatinny Quadrail Set

Items designed to fit a Weaver rail will generally fit a Picatinny Rail, but the inverse is not usually the case. This rail system is standardized and has consistent spacing, and while Weaver and Picatinny may look the same the dimensions are different. It is sometimes referred to by its official title of MIL-STD-1913. This later system was developed for military use in the mid-1990s. The first rail system developed for optics was the Weaver system and you still see it advertised today, however it has been in large part replaced by the Picatinny rail system.

And if you wanted to get tactical by adding a flashlight to your rifle, Duct Tape (Bill Murray style) was your only option. In the bad old days if you wanted to add an optic to your rifle you had to take it to a gunsmith who drilled and tapped the receiver in order to install scope rings.

How to install keymod accessories