If one decides to put in some study on the AR platform you will find that several things can be done when you are building then that will enhance the accuracy of them besides the barrel and trigger . True the upper to the barrel and true the bolt carrier area of the upper to the barrel extension change out the extractor make sure the bolt is true and has no binds when locking up ,the type of gas block ect. this is just some of the things that can be done to help them be accurate . Early on I had some bad experiences with the AR type of fire arm and didn't look at them for some years but I like to study and figure things out so started to study them they are a challenge and can be quit accurate . The ammo can also be tuned for them .