I am building 2 AR's, one in 300 blackout, and the other 5.56. The 300 is pretty much a done deal as to what I am using for the barrel, but the 5.56 I am unsure if I should go chrome lined barrel or not. I know chrome lined bores last longer and are less accurate, but exactly how much does accuracy suffer? The places I have been looking don't seem to be able to keep the chrome lined barrels in stock except for the cheap ones, and I'm not sure I want to go down that road. Maybe I'm making this out to be more than it is, but these 2 AR's are going to be my first, and I haven't been able to find much of an argument about chrome or not other than chrome lasts longer and non chrome shoots better. I got tired of working on my friend's and my brother in law's all the time and not having one of my own. Those two bought rifles off the shelf and dumped enough money on upgrades into them so far they could have built two for what they spent on one. Of course the labor was cheap since I did the work on them for next to nothing.