During the course of a little over 50 years of building gun leather along with saddlery and harness we've developed these holster molds which are also called dummy guns, replica guns, non-firing guns, gun models, along with other regional nicknames. Needless to say I have used cast aluminum models, hand made wooden holster plugs, and others but each had their shortcomings - the aluminum ones that I had marked the leather and never were quite the right size, the wooden ones swelled and warped, and they were all I thought too expensive for anyone other than maybe a giant holster company.
After trying several types of castable resins, polymers, and even plastics we settled on the polyurethane that we use and have had good luck with. It is not brittle but has enough hardness and strength to do a respectable job.
There are several advantages to using a holster mold over using a real gun - first off since this is solid cast resin polymer you can shape wet leather around it and it will not mark or discolor the leather, secondly you won't need to stick the pistol into the wet leather and possibly damage it, thirdly it's safer because you'll be handling something that has no possibility of ever having an accidental discharge and also it won't be necessary for your customer to leave his weapon with you for an extended period of time.
These models also work well to display holsters where real weapons would be inappropriate or unsafe. They could be used to illustrate how the pistol would fit and ride in the holster. These models are an off white in color and have a red muzzle. If you want to use these as a display or decorator item they can easily be painted.
