From what I have seen the tube holding the spring detente for the slide stop and the safety has been installed or in some cases an integral part of the frame and the "coating/finish" is put on with the tube installed. This makes the interior of the tube "under spec" diameter and the spring and detente's are barely able to move. I would recommend total disassembly and removing both and remove the spring assembly then run a correct diameter (I don't know what that may be) drill bit (by hand) through the tube to clean it out and bring it to spec diameter.

__________________
H Richard
SWCA1967 SWHF244