Glock has come out with factory threaded barrels for the G19. They don't specify if it is Gen3 or Gen4. Assuming they are Gen4 spec, will they function correctly in my Gen3 H-series G19? In other words, are barrels interchangeable between Gen3 and Gen4 Glock 19's? Specifically Gen4 barrels into Gen3 guns, and not the other way around. Anyone with one of these threaded barrels put through a good amount of rounds with a Gen3 Glock 19? Suppressed and unsupressed.