I'm going to install a Lilja 1.00" barrel in a CZ 457 Standard Varmint stock. My question is, do I start at the bottom of the channel with smaller socket/ sandpaper? Or, start at top of channel with final width of socket and sand paper needed. I just want to avoid the top finished edges from getting chipped or scuffed. I suppose I could tape off that top edges? I'm open to all suggestions / ideas! Thanks! 