Questions about my first AR build???

[LRRPF52]

That is perfect. I also used my chamfer/de-burr tool to chamfer the edges at the cut, so that it wouldn't have any sharp edges to combine with carbon or lapping compound and screw up my chamber. I only place a small amount of lapping compound on the lugs, since that is the only area being lapped.

I think I used an M16A2 rear sight spring. You do need to remove the ejector from the bolt, and I have the Brownell's AR15 tool for that-makes it an easy job.