Re: Interchangeable backstraps for Glocks
I doubt that you will ever see this for a Glock manufactured firearm. They really haven't changed their design since it was first introduced, and it is so popular now that I doubt they ever do.
If it is something you think you may really be interested in, there is a company called CCF Raceframes that makes an all metal (Stainless, Aluminum or Titanium) frame for Glock pistols. Their frame uses an interchangeable backstrap design.
BTW... Welcome to the forum. Hope you find it to be a useful place to visit.
"...As to the species of exercise, I advise the gun. While this gives a moderate exercise to the body, it gives boldness, enterprise, and independence to the mind. Games played with the ball, and others of that nature, are too violent for the body, and stamp no character on the mind. Let your gun therefore be the constant companion of your walks."