Models made of leather
Holster fit and break in.
Use an UNLOADED GUN for testing holster fit. By design, your holster will fit tight at first. With use, the leather fibers will stretch to provide a proper fit. (Don’t force your gun into the holster if the fit is too tight. It may be difficult to unholster your gun.)
Do not apply any kind of oil or leather softener to your holster. These will soften the leather so it will not retain the mold and consequently lose its retention properties.
If you can holster your gun without forcing it, work the gun in and out of the holster a few dozen times. Next, wear the holster and with your unloaded gun, repeatedly draw it in and out. The natural movements of your body will further help break it in.
If the holster is overly tight you can stretch it by inserting your completely unloaded gun into a thin nylon dress sock and force the gun and sock into the holster, twisting the gun as you do so until the gun is fully seated in the holster. Allow the gun to remain in the holster overnight. Next, repeatedly draw your gun in and out of the holster a few dozen times. Remove the sock and try drawing your gun. If it is still too tight, repeat the process.
If your holster has a retention strap it may be difficult at first to get it to snap close. With your completely unloaded gun fully seated in the holster, hold the gun grip with one hand and push on the gun while pulling the retention strap with your other hand. Keep constant pressure on the strap as you bring it over your gun to meet the other half of the snap. Have patience. With a little work the strap will stretch and you will get it to snap.
Once you have the strap snapped over your gun, keep it fastened overnight. Repeating this process will eventually stretch the strap to the point where it will easily snap close.