Factory Glock replacement barrel for Glock 19 frames. Drop-in fit on Glock 19 Gen 3, Gen 4, and Gen 5 slides cut to OEM spec - no fitting required. This is the same barrel Glock ships from the factory in a new Glock 19. Frame and Slide Compatibility Fits all Glock 19 generations (Gen 3, Gen 4, Gen 5) and Glock 19-pattern slides built to OEM dimensions. The Glock 19X and Glock 45 use the same barrel; long-slide variants do not. Finish Factory black nitride (Tenifer-equivalent) over Glock-spec barrel steel - same metallurgy and surface treatment as the OEM barrel that ships in a new pistol. Specs Caliber: 9mm Luger Rifling: polygonal (factory Glock profile) Length: 4.02" - Glock 19 standard Finish: black nitride Manufacturer part: SP03577 Fit: Glock 19 Gen 3, Gen 4, Gen 5 Polygonal rifling does not pair well with unjacketed lead bullets - run FMJ or jacketed defense loads only. Confirm your slide is a standard Glock 19 cut (not 19X long-slide, not custom aftermarket lengths) before ordering. DISCLAIMER: "GLOCK" is a federally registered trademark of GLOCK, Inc. and is one of many trademarks owned by GLOCK, Inc. and GLOCK Ges.m.b.H. Neither 3CR Tactical nor this site are affiliated in any manner with, or otherwise endorsed by, GLOCK, Inc. or GLOCK Ges.m.b.H. The use of "GLOCK" on this page is merely to advertise the sale of GLOCK pistols, parts, or components. For additional genuine GLOCK, Inc. and GLOCK Ges.m.b.H products and parts visit www.glock.com.