a substantially nonbonded composite / metallic gun barrel is disclosed . the gun barrel has a metallic liner and a composite casing disposed thereabout . unlike composite / metallic gun barrels of the prior art , the embodiments of the present invention provide little if any bonding between the composite casing and the metallic liner so as to decrease the warping of the gun barrel caused by the differing thermal expansion coefficients of the composite material and the metallic liner . in accordance with one aspect of the invention , a short binding layer is used to hold the composite casing to the metallic liner adjacent the chamber which holds a cartridge to be fired . the short layer prevents rotation of the casing and the liner with respect to one another , while preventing little risk of warping . in accordance with another aspect of the invention , a holding pin is inserted in the gun barrel to prevent the metallic liner and the composite casing from rotating relative one another .