PTR Industries PTR 91 308 Winchester 20 Round Rifle Magazine Black. Specifications for PTR Industries PTR 91 308 Winchester 20 Round Rifle Magazine: Manufacturer: PTR Industries Color: Black Magazine Capacity: 20 Round Caliber: .308 Winchester Gun Model: PTR 91 Package Contents: PTR Industries PTR 91 308 Winchester 20 Round Rifle Magazine What firearm models does the manufacturer say PTR Industries PTR 91 308 Winchester 20 Round Rifle Magazine is compatible with? The manufacturer says that PTR Industries PTR 91 308 Winchester 20 Round Rifle Magazine is compatible with PTR 91PTR Industries PTR500098-20RD: PTR 91 308 Winchester 20 Round Rifle Magazine Black