Upper receiver lapping?

[A5BLASTER]

Here are a couple shots of one I did last Friday. It wasn't as far off as the last one I did, but you can tell in the first shot that it is slightly uneven. The second shot is closer, but still not completely even. I didn't get a shot of the finished upper before the barrel was installed.

I definitely think it's worth taking the time to do. I grease up the lapping tool shaft and use a drill while holding the upper in my hand to reduce lateral loading.

I lock mine vertical in my vice and use my cordless drill to power it as well. Been useing clp on the guide shaft as a lub.

Seems to work good. I typically wait till I have broken the action in by hand cycling a wet bcg/buffer before I go lapp it and install the barrel.