On my open gun, STI frame, slide, Nowlin barrel, major 9, with a hard chrome finish, the slide has developed a problem going all the way forward. When I lower the slide slowly by hand on an empty chamber it stops 7/32 short of going into battery(which appears to be about the distance a slide goes reward to unlock), a slight pressure or bringing it forward with only slightly more speed and it snaps into battery.
When running the gun with a recoil master installed I was having the same problem fairly frequently, by switching to a std rod and 11# ISMI spring it runs better but still stoped a couple of time today.
Any ideas?? I have checked for burrs and find none. the locking lugs are square and appears that the gun locks up tight, it is a fairly new gun with about 3 to 4,000 rounds through it.