Product Description
NO THREADSThese are for the MA Compliant LITE Model 43921 with an O-Ring where threads would normally be.
These have too large ID to be tapped for 1/2x28
BUT
You could find an O-Ring to fit inside the inner groove and get one to possibly work on threads.
Ruger shipped us these by mistake
They have minor chips in the finish on the corner/edge where they would meet the barrel
Factory Ruger part
Part #3 in Exploded View