I dry-fire mine before storing them, but it's probably more of a "We did it that way in the military" thing than anything else.

The firing pin/striker spring in a Glock is only partially compressed during cocking; your finger and the trigger complete the compression stroke just prior to firing, so the spring is not fully compressed while at rest (unlike some other gun designs).

If you're going to dry-fire, I recommend having an extra-safe direction to do it. Always practice and remember basic safety rules, and keep in mind the two worst noises a handgun shooter will ever hear:

- A "Click" when they expect a "Bang" (in defensive use)

- A "Bang" when they expect a "Click" (during so-called dry-fire)

I'm away from home for some pretty extended periods of time - six month to a year has been common. I go for the "click" before storing them. I also clean and then use the factory style copper lube before doing the "click". And due to over training, I check as follows before pulling the trigger.
1. REMOVE THE MAGAZINE.
2. Lock back slide and check for round in chamber.
3. Cycle the slide a couple times and repeat step 2.
4. Stick finger in and look through barrel to see finger.

NOW I release the slide, point in a safe direction, and pull the trigger.
Don't want no Bang if I'm expecting a click...

Guns go back in factory box and get locked up in the gun safe. Key goes to brother in case I have to ride back in the bottom of the plane...

OH - unload the mags...

When the trigger is back, you know that there can not be around in the chamber. When it is left forward it's possibly loaded.