adapted to provide similar anti friction and anti adhesion performances coefficient of static friction lower than 0 1 such as other polymeric materials e g pom u2014 polyoxymethylene or even ceramic materials moreover the sleeve can be entirely made of such material or have at least a surface treatment or lining film of the anti friction material over the inner surface the surface that remains exposed for contact with the handgun inside the holster in the inserted configuration in order to make perfectly stable the engagement between the sleeve 3 and the shell 1 in the inserted arrangement the recess 2 advantageously has opposed to and spaced apart from the handgun insertion top end 1 a a longitudinal bottom end in the form of a step defining a sleeve stop bottom face a groove 2 a is out in said bottom face and locks a correspondent longitudinal bottom end lip 3 a formed by the sleeve 3 whereby the engagement between said groove and said lip prevents said sleeve from displacing in a plane orthogonal with the longitudinal direction at the handgun insertion and 1 a a further stop to the insertion position of the sleeve is provided by a sideways rim 3 b that projects over a transversal plane and is adapted to abut against said end 1 a possibly as in the example forming a step that accommodates the rim not to generate additional bulk in the longitudinal direction finally the safety against the disengagement extraction of the sleeve 3 is advantageously increased by a locking peg 5 see namely fig6 that is forced in a sideways running through seat resulting from the mutual correspondence of two holes 1.