I am just about to drill my trunnion and barrel for pinning; the trunnion isn't welded to the receiver yet. It seems it would be easier to have the trunnion and barrel assembly out of the receiver so I can clamp it in a drill press vise for proper positioning. This leads to my question: How do I set the alignment of the hole already in place so I do not end up with an off center hole? And, do I drill successively larger holes until I get to 7/32"? I'm not all that worried about pressing in the pin; it will be covered with weld once I am done. I know I should have mentioned this earlier, but I already headspaced the barrel at .016", and set up witness marks on the trunnion and receiver for proper re-alignment during re-assembly.