The one I have is all metal, but has a formed "bead" at the top. I took it out to the belt sander tonight and shortened it by the height of that bead... we shall see what difference it makes. I'll keep shortening it till it shoots like I want and then buy a firesight in that height.
3006bluffhunter.. thanks for the offer, but I think when I figure it out, the firesite I think will fit the bill.
Ian