(There was a very limited run of 389 Glock 19X pistols with threaded barrels for a special contract, but only 8 are in private hands, including the one I own.) 45 is also available in MOS with threaded barrel in FDE. G45 is available with factory threaded barrel in black, gray, and FDE – all come with suppressor sights – some Ameriglo.G45 is available in MOS (in black, FDE and gray), 19X isn’t.G19X doesn’t have the newer breech cut that the newer Gen 5 pistols like the G45 have (which aids in ejection).Also would require the #33601 11 coil mag spring). G19X comes with 2×19 round mags and 1×17 round mag (although you can add ‘+’ floor plate, which is Glock part #7151, and insert, which is part #7165 to 17 round mags to make them 19 round.Current production Gen 5 G45 has front serrations, G19X doesn’t.G19X has a removable lanyard loop, G45 doesn’t (although Glock does make a black lanyard loop).There have been more than 20 versions of mags just for the G17. I put quotes around “Gen 5” because mags aren’t really generational like the pistols are. G19X won’t take “Gen 5” mags unless you swap the floor plates.G19X uses maritime spring cups, G45 uses normal spring cups (although they’re both interchangeable).G19X is coyote (NOT FDE), G45 is available in black, FDE, BFG, and gray.G19X has the nPVD slide finish, 45 has the standard Gen 5 nDLC finish.
I have compiled a list of differences that I have noticed and included them below. There are a number of differences between them that make such a comment somewhat silly. I have seen some people posting that the Glock 45 is just a black 19X.