Perhaps I determined the direction of the RR groove using a more time consuming way {swamped bbl} but it came out as I wanted. After measuring the swamped bbl in a few places, I then determined dims that measured from the top flat to a dowel pin laying in the RR groove. To really make the RR groove consistent, a size board that was 12" long w/ the desired radius filed on had a sheet of 150 grit sandpaper that was used to make the groove straight. No guessing w/ this procedure but it did take awhile, so after the 4th LR, began having the work done.
All the Bucks County LRs I've built have a 1/16" or slightly less web at the breech and 5/32" at the muzzle and used a #6-32 front lock bolt and an #8-32 for the rear. Never had any problems using a #6-32 lockbolt...afterall it only holds the lock in and the inlet does most of the work. The 1/16" web requires a special bbl lug for the 1/16 dia music wire which I use for all the pins in a LR.......Fred