I don't have any money to purchase a 10-32 x 3/16 set screw but I have a set of m4-m6 set screws. When I was testing in one of my other lowers, it seemed to work but when I put the detent and spring in and then put the screw in, the screw doesn't want to thread into the hole. It seems that the spring stops the screw from doing deep enough so it can bite into the plastic.
Overall, i'm having a hard time trying to get the screw to bite.
The m5 I am using 3.6mm thick.
