The mouth of the holster can be curved outward slightly. If the holster doesn't come that way, you can always bend it out slightly by dampening the leather and curving it outward slightly with your hand. No matter who makes your holsters, you may want to wet-fit them to the gun anyway. It is a simple process, which entails running tepid water inside and outside the holster for about 15-20 second, or until the leather appears completely wet. Do NOT soak the leather overnight or any such nonsense! Wrap the gun tightly in a plastic baggie and insert into the holster. If the gun has an ejector rod offset to one side of the barrel (most Colt's Single Actions do), obtain a hardwood dowel, sand one end rounded slightly and insert into the holster, before the gun. A 3/4" (19mm) will do to form the body for the barrel and front sight. Note where the ejector thumbpiece shows in the holster body. Take a 1/2" (12.7mm) dowel also rounded on one end, and use it to form a track from where the thumbpiece comes when the gun is in the holster up toward the mouth (top). This is to prevent the thumbpiece from forming a pocket that will trap the gun in the holsters. Allow the leather to dry with the bagged gun in the holster for 6-12 hours (overnight). Remove the gun and allow the leather to dry for a couple of days, periodically inserting and withdrawing the gun from the holster to be sure the leather hasn't shrunk too much. Use a bit of care. You can always repeat the process. Treat the dried holster leather with a good leather conditioner (Do NOT use straight Neatsfoot oil!), LIGHTLY. Hope this helps.