I never bothered to memorize the Glock numbering scheme. I just ask for a specific size and caliber. Since, I prefer a compact 9mm. Therefore, I typically buy a Glock 19.
The reason I don’t keep up with the numbering system is that it does not make sense for the user. They are not numbered in order of caliber or size.
Glocks are numbered by the order Gaston Glock gets patent number. I would prefer them listed by caliber and size.
Why not put all the 9mm guns in a row, then number by size. Glock 1, 2, and 3 could be the standard, compact, subcompact. Then the 4,5, and 6 could be the .40 S&W guns. Next could come the .45 ACP in the 7, 8, and 9 models.
That would be much easier for me to remember. In contrast, the reason Glock pistols start at 17 is that Gaston Glock had 16 patents before guns. He originally made polymer kitchen utensils before he decided to go after an Austrian military contract for a new pistol.
(* I made that number up. There is not a Glock 324 but I expect some day Glock may make one)
Here is a Basic Breakdown
- Glock 17 is a 9mm full size
- The 18 is the select fire version
- Nest, the Glock 19 is the 9mm compact
- 20, 21, 22 are all full size, with the 20 chambered in 10mm, the 21 in .45 acp, and the 22 in .40 S&W
- 22, 23, and 24 are all .40 with the difference being size. The 23 is compact, the 24 is sized for competition.
- Glock 25 is a compact .380
- 26-30 are all sub compacts. In order of caliber, they are: 9mm, .40, .380, 10mm. Lastly the 30 is a .45acp
- 31, 32, and 33 are all chambered in .357 sig. the 31 is fill sized, the 32 compact, and the 33 is subcompact. This is the series the TN Highway patrol carries.
- 34 and 35 are competition guns. the 34 is 9mm. the 35 is .40 S&W
- The Glock 36 is a slimline .45 acp
- Lastly, the 37, 38, and 39 are chambered in .45GAP. the 37 is the standard full size, the 38 compact, and the 39 the sub compact.