I bought some 5-40 x 1/4" button head screws and used them to add some "tacticool" to my AR lowers. The front hole in the Magpul trigger guard is already a 5-40 thread the rear is not. I considered going one size larger for the rear but that would mean I would also have to open up the holes in my lowers, not gonna happen.
I used JBWeld and filled the rear hole. First I cleaned the hole with brake cleaner and let it dry. After it dried I mixed up my JB Weld and made sure to leave the left over close at hand so that I could monitor the drying stage. I loaded a toothpick up with JB and ran it through the hole making sure to coat it completely. I then pulled the toothpick out and cleaned the opening on one side with a straight edge and then applied a piece of scotch tape.
After 1.5 hours I cleaned the other side of the hole using a straight edge and applied another piece of scotch tape. I used some release agent (cooking spray!) on a straightened paperclip and inserted it through the scotch tape all the way through the hole as closed to dead center as I could get. I held the trigger guards under a hair dryer for 10 minutes and then let them sit.
After 2.5 hours I removed the paperclips and as you can see it left a channel all the way through. I then used a drill bit slightly undersized than the 5-40 screws. I then used the screws as my "tap" by applying some cooking spray and then lining the screw up with the hole while holding steady downward pressure I worked them in and let them sit overnight.
After sitting overnight I backed them out and cleaned up the trigger guards one more time and then installed them on my rifles.
I plan on ordering a helicoil set and will remove the JB Weld and tap the roll pin hole and insert a helicoil into the rear hole to make for a solid connection. The JB Weld is solid but I want to be 100% sure.
I posted this for those that do not have all of the tools to the helicoil method. It is pretty straightforward and simple. I have about 80 extra screws if anyone wants some shoot me a PM.
I used JBWeld and filled the rear hole. First I cleaned the hole with brake cleaner and let it dry. After it dried I mixed up my JB Weld and made sure to leave the left over close at hand so that I could monitor the drying stage. I loaded a toothpick up with JB and ran it through the hole making sure to coat it completely. I then pulled the toothpick out and cleaned the opening on one side with a straight edge and then applied a piece of scotch tape.
After 1.5 hours I cleaned the other side of the hole using a straight edge and applied another piece of scotch tape. I used some release agent (cooking spray!) on a straightened paperclip and inserted it through the scotch tape all the way through the hole as closed to dead center as I could get. I held the trigger guards under a hair dryer for 10 minutes and then let them sit.
After 2.5 hours I removed the paperclips and as you can see it left a channel all the way through. I then used a drill bit slightly undersized than the 5-40 screws. I then used the screws as my "tap" by applying some cooking spray and then lining the screw up with the hole while holding steady downward pressure I worked them in and let them sit overnight.
After sitting overnight I backed them out and cleaned up the trigger guards one more time and then installed them on my rifles.
I plan on ordering a helicoil set and will remove the JB Weld and tap the roll pin hole and insert a helicoil into the rear hole to make for a solid connection. The JB Weld is solid but I want to be 100% sure.
I posted this for those that do not have all of the tools to the helicoil method. It is pretty straightforward and simple. I have about 80 extra screws if anyone wants some shoot me a PM.
