Why do the .45 caliber Glocks have octagonal rifling vs the hexagonal rifling in the other calibers?
The octagonal rifling provides a better gas seal in the large caliber .45 ACP. Notice how the image on the right has a lot less space between the bullet & barrel compared to the image on the left: Back To Top How long will a Glock factory barrel last? Thousands and thousands and thousands of rounds. The inside of the barrel is much, much harder than a copper-jacketed or lead bullet and will not wear appreciably with normal use. Chuck Taylor has put more than 157,000 rounds through his Glock 17 without ever replacing the barrel.