Now start my centerline . Now this centerline is important to keep everything centered and straight . I'm sure there are different ways of doing this but just my way here ....this one is easy as the blank is way over thick . If its thin and warped you have to fight it a bit to make sure you get that barrel in there , first part in , most important and dictates everything else's location . This one ,like I said is easy and notvwarped too bad do I just found center at the breach and checked both ends , muzzle and butt , and there's lots of room so I just found center at muzzle end and laid this metal at my two marks ...it was fine at the butt ,plenty of room , so it'll go there just fine . If it was bad I'd just try to use that straight edge and fit it all in there . By the way ....just picked this long aluminum stock up at the hardware , 7ft. Works really well ....before I had to kinda piece the lines together and then eye ball the center line and see if its straight or not ....