Reply to Keith:
No, barrels not fully open as I took the photo with one hand holding the gun open with the other. If I had put the gun in my vise to be able to take the photos with the barrels at maximum drop the hooks would be marginally short of engagement.

As to the manner by which the hook keyway earned it's slop my guess is as good as anybody's.

Last edited by LetFly; 03/21/20 03:34 PM.