Nope. You're supposed to use a barrel-alignment jig to center the barrel. Then you carefully file off the amount necessary to get clearance enough to make the hood fit into its slot. I didn't want to spend the money, so I use the file-a-little, put it together, file-a-little more-till-it-fits method.
I was just wondering. I did the sides already using your method. I found a procedure for calculating the hood length just never saw anything about the sides of the hood.
