Hello, I’m currently starting up a 6mm ARC build and am trying to decide on a upper/lower combo that will pair well with this long(ish) range build. From what I’ve read im currently leaning towards the zev billet receiver set because it seems like it has some tight tolerances all the way around. But wanted to see if anyone has any experience with them, or any recommendations like SLR or any other brand? Thanks for comments. Im putting good money into this and want to get it right the first time!