Abstract: A composite projectile barrel having an inner barrel section and a composite outer barrel shell aligned coaxially with the inner barrel section is described. The inner barrel section may be made from a metal or metal alloy. The composite outer barrel shell may include two or more layers of carbon fiber prepreg and a layer of non-woven nanofiber web membrane disposed between adjacent layer of carbon fiber prepreg. The carbon fiber prepreg can include a weave of carbon fibers in a nanoparticle-reinforced resin matrix, with the resin content being less than or equal to 35 wt % of the carbon fiber content. The non-woven nanofiber web membrane can be Xantu.layr™.