I was wondering if there is a threaded nut the front sling swivel stud screws into or if it screws into the barrel. I suspect the former. I guess I could find out by taking the stock off but I don't want to.

Also, what would be the preferred way to secure it. I've considered Lock Tite and Epoxy glue.

Your on the right track. I have used JB weld on these befor from the inside.