Exactly what it’s supposed to be - Wheeler Fine Gunsmith Equipment AR 15 Receiver Lapping Tool

This tool works exactly how it’s supposed to, building a better quality upper while saving time and frustration. I’ve done a few uppers so far, one so bad it was unusable, one spot on perfect, and another just a hair off made perfect. It’s critically important that you keep any grinding compound or dirt out of the inside and oil the shaft. Each time you pull out to check only go just far enough to re-smear the compound. If you pull too far, clean everything out and restart. I have more pro tips, but have to save those for a video. This is a tool I’ll use on every one of my builds.