I have been carrying a G23 in a Summer Comfort behind the belt leather holster for a few years. The weapon stays in the holster so I would think the holster should be broken in by now. My problem is that the holster is very tight to draw no matter how loose of pants I wear. Is there anything I can do to loosen it up?
I have soaked a couple of leather holsters in water, wrapped my pistol with clear plastic wrap like you would use in the kitchen, put the pistol into the holster and put them both in front of an electric heater. When the holster dries put a little neats foot oil inside it, now you have streached it and per say custom fitted you pistol to the holster. That should allow you to remove your pistol with a lot less effort.
You may want to try putting your gun into an old sock and then putting it back in the holster for a couple days. If on doesn't do too much then you can try two. I have done this twice with two different holsters and has worked great.
I bought a holster from http://theholsterstore.net/ a few months back and the recommended wrapping the gun in wax paper over night to aid the break in process. It worked for me. I think it both stretches the leather a bit and coats the inside lightly in wax (not enough for it goo up your gun though).