Firearm series numbering guide (Glock, Beretta and S&W).

There are so many pistols and revolver series that it is sometimes difficult to remember what is what.
To be honest most of time there is just a single variant of a given modelgun, but sometimes we are spoiled ;-)

Glocks come in various chambering and size. Glock FAQ compares all models in nice tables:
http://www.glockfaq.com/content.aspx?ckey=glock_faq_glock_model_guide

	Subcompact	Compact	Standard	Competition	Slimline	Short Frame
9x19mm	G26	G19	G17	G17L/G34
.40	G27	G23	G22	G24/G35
.45 ACP	G30		G21		G36	G21SF
.45 GAP	G39	G38	G37
10mm	G29		G20
.357	G33	G32	G31
.380 ACP	G28	G25

S&W pistol series numbering is covered in this article from "Modern Firearms":
http://world.guns.ru/handguns/hg01-e.htm

S&W revolver frame sizes, chambering and series numbers are listed here:
http://en.wikipedia.org/wiki/Smith_&_Wesson#Notable_revolvers

Beretta 90 series are covered in Wikipedia table:
http://en.wikipedia.org/wiki/Beretta_92_Models

Beretta 80 series (Cheetah) are described (no table) in "Modern Firearms" website:
http://world.guns.ru/handguns/hg108-e.htm