'For Shooting Reloads on Glock'
If you look around the local internet firearms forums or local sales/auction sites, you will notice that most of them recommend the use of these barrels so you can shoot reloads on Glock pistols. Glock pistols come from the factory with its own patented type of "Polygonal Rifling", which they claim lessen friction between the barrel and the bullet, thus increasing the velocity of the bullet as it leaves the barrel.
Unfortunately, such rifling tends to build up more deposits in the barrel at a faster rate, which, if the build up is sufficient enough, could cause certain types of catasthropic failures during firing in one form, or the other. This is the reason why Glock in their manual specify that lead bullets NOT be used using the stock or factory barrel.
