The Gen 5 guns eliminated the locking block pin which Glock felt was necessary in all the calibers above 9mm.Ever wonder why Glock has no Gen 5 .45/ acp?
Basically there are no Gen 5 guns in any calibers other than 9mm. That "generation" was really just a modification intended to make their 9mm pistols more attractive in the U.S. military sidearm competition.