Squaring & Lapping the Upper Face

[MikeGideon]

I have squared and bedded 3 so far, all CMT Billet uppers, and all Grendels. Unfortunately, none have made it to the range yet. The receivers were probably above average in quality, and still weren't completely square. You can tell by how the finish comes off the end of the receiver. I used the Wheeler lapping tool.

Couple of tips... Oil the bejeesus out of the pilot, and make sure none of the lapping compound makes it into the receiver. That will happen if you pull the tool out too far as you are checking progress.