I keep sorting though my locking shoulders for FAL when headspacing. You can file a couple thou but its getting where the only shoulders I have left are way to thick. So, my evening project build a fixture to machine locking shoulders.
For me the trick part was measuring the exact angle between the lock surface and the locating ear. its 11 degrees. Actually I got 11 on two shoulders and 11.5 on another. See pic for my setup
I then machined a block to hold the locking shoulder. Couple points on this jig. I made the locating ear stick up 1 RCH (red c$%^t hair) so the shoulder would clamp tight in the vice. I also made the block exactly 1 inch higher than the shoulder measurement. Then I can put a
1-2 mike on the shoulder in the jig and measure exactly where its at without removing from the mill.
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