Sorry to have taken so long to answer your thread keith...was at an archery tournament all weekend. I measured the thickness of my Virginia's forend last night, for the first time, because I don't aim at a particular dimension when I'm making it. The amount of wood along the barrel channel at the muzzle is determined by the apex of the curve of the nose piece, just as Ken said. The nose piece in my parts set was smaller that the muzzle of the barrel, and I had to file quite a lot out to make it fit. This ended up favourably, as the distance from the apex to the side flat of the barrel is just over 3/32", actually .098" or a #40 drill bit. This continues toward the breech evenly until I arrive at the entry pipe where the width gradually increases, ending at just under 1/8" at the molding around the lock panel, actually a #31 drill bit. I will add, regarding the shaping of my forend, that the top edge of the forend right from the lock to the nose piece is well below the centre line of the barrel. This came about because of lock inlet, and similarly, the nose piece's installation. The result is that I was able to give the whole forend a nice round convex shape to take away any hint of slab sidedness. Even though this rifle has a voluptuous butt, her forend is lovely and slim. This is one of my favourite rifles.