Originally Posted by Magnum Brown
I'm new to the Forum and guns. About 6 months ago I purchased a Glock g21 .45 ACP, with 3 mags (One extended)
Based on the pics, I'm pretty sure it's a Gen 2.5. My question is... How can I tell the difference between a gen 2.5 and 3? (Sorry if this is a silly question, but Im a newb)
I just dropped by and caught one I can answer.
In the Glock 21 what we call gen 2.5 means it has the finger grooves but the frame does NOT have the accessory rail. There used to be pics of these in the old Serial Number Thread, but I couldn't find them. I'll look again later.
If you have neither rail nor finger grooves it is gen 2.
If you have finger grooves only, it is gen 2.5.
If you have both, it is gen 3.
Gen 2.5 means something a little different in the subcompact 26 and 27 than it does with your large frame 21. DJ did a nice job of explaining what a gen 2.5 means for the subcompacts. I think in all uses, "gen 2.5" simply refers to intermediate step between gen 2 and gen 3. There is no such thing as a gen 2.5 in a Glock 19 or 17 for instance, nor for several other models.
It gets confusing and not everyone agrees on these definitions, especially with the subs. If my definitions above were applied to the subcompacts, they would still be gen 2.5 since they still lack the rail.
I've "over answered" your question.
You can use your serial number alpha prefix to get the date of production if you are interested. Hopefully the link in my signature is still good.
ETA: The first one I see posted in the SN thread is this one:
CGD*** G-21C 2.5 1997-05-01
I would not be surprised if there were earlier ones though. Someone might have submitted their SN and not realized that the finger grooves meant we'd call it Gen 2.5.
I hope you like your G21 and that you enjoy it.