An insert for a collapsible firearm receptacle of a concealed carry holster includes a body that may fit snugly into the collapsible firearm receptacle. The insert may also hold the collapsible firearm receptacle in a somewhat open arrangement to facilitate the ready insertion of a barrel of a firearm into the collapsible firearm receptacle and removal of the barrel of the firearm from the collapsible firearm receptacle. The insert may include an outer wall, a front wall, and a rear wall that define an interior of the insert. The insert may also include a lip that protrudes outwardly to extend beyond an upper edge of the collapsible firearm receptacle. Concealed carry holsters that include the insert are also disclosed, as are methods of using the insert and concealed carry holsters that include the insert.