Deles,
Same as for any cartridge.....
Start with the LARGEST opening and shoot single rounds. Enlarge the opening until the bolt begins to lock open after the brass is ejected. Then try to shoot multiple rounds from a clip. If you have reliable function from the clip, then you are there. If you are still getting short strokes, then enlarge again until the short strokes stop.
Best regards,
Swampy
Garands forever