This is a printable "teklok" style mount. Use this for your mag carriers, shotshell caddies, knife holsters, whatever you want! I don't recommend using it to actually carry a pistol though, while it may hold up it would be wise to simply use the real deal.
-Print the parts
-Drill out the holes that the dowel pins will go in with a 3/32 drill bit
-Press in two (one on each side) 3/32 diameter by 7/8 long dowel pins (ACE hardware had them for me)