Word of caution:
I broke off the head of my bbl bolt on the 10.5" today upon reassembly. I've taken the bbl off probably a dozen times now. I'd highly recommend anyone taking their bbl off that frequently to go ahead and replace it when you get up around 1/2 dozen times or so.....
I always just use a standard allen L shaped 1/4" wrench (5.625" long, so over leverage wasn't an issue) and it snapped the head off. The bolt was not defective. My gut feeling in working with a lot of fasteners in the aerospace industry is that over time, the bolt continues to stretch in the threaded portion and eventually, it just snaps. IMO, this was just run of the mill metal fatigue.
I'm considering going to a set screw instead of the socket head screw next time around (after I drill and easy out or tap the current clusterfuck) as this problem cannot occur with the set screw....though I could conceivably strip the head....but allen head set screws would also act like a self centering pilot hole if that happened.
Anyone know off hand what the correct length is for the set screw? Anyone know what size allen bit fits this set screw? I'm concerned that you may overtorque the allen wrench itself if it is significantly smaller than the 1/4" wrench used on the socket head screw. Finally, anyone know if the set screw (or the socket head allen screw for that matter) has a special degree chamfer on the end that mates to the bbl or if it's just a standard taper? I'd like to just pick this up at the local hardware store tomorrow as opposed to having to order from Kermit.
PS. I'm going to post this as a new thread to hopefully get the info on the bolt more quickly.