First off, avoid the Butler Creek tuff, It's cheap for a reason. While you're on RimfireCentral, do some searches on thier stuff, especially the so called "carbon fiber" bbls. If you're serious about building one of these up with accuracy in mind, don't go that route.
Done a bunch of these builds, have 3 midbuild or waiting and 2 more planned. Got any Q's send a PM. Glad to help ifI can.