In the old days, you'd soak your holster in water. Then you'd grease up your gun and wrap it tighly in plastic. The gun was introduced into the holster and the holster molded to fit the gun. The holster was allowed to dry before the gun was removed (then the gun was unwrapped, cleaned and inspected for rust). Afterwards, the holster should fit the gun like a glove. Got this from Bill Jordan's "No Second Place Winner."