Unless you already have, are going to buy, or build, a jig to hold the front sight assembly perfectly straight while you drill and ream the holes through both the front sight and barrel, you will in all likelihood end up with issues that at the very least will result in a canted front sight, and at worst require a new barrel and front sight assembly. If this is your first build, and you are not a machinist/mechanic/etc. you should probably either get someone to do it for you, or change your build plan.
Regards.
Mark