This increases accuracy and zero repeatability during disassembly and reassembly when accomplishing servicing. Within the left during the graphic here we can see the extra cuts designed in to slot 28 (in comparison with the unmarked slot to its’ suitable) which allow secure locking of the original KAC ribbed rail https://lorenzowkugo.idblogmaker.com/26448171/5-easy-facts-about-knights-armament-m4-quad-rail-described