Hi John, we regularly scrap batches of 100's of aircraft life jackets at work that are C02 operated, some have powerlets similar but slightly different to anything used in any airgun (I used to see guys popping powerlets for days then scrapping the containers and thought "what a waste").

Anyway, the shelflife is to re-weigh at 4 years and there is a percentage that is allowable, much like a fire extinguisher test, on my gas inflated lifejackets on the boat they just say change at 4 years regardless.

Thing is, I have seen containers 20-25 years old from storage that are still perfect, but the are very high quality as you would expect, so maybe it's down to the type of closure as mentioned by another poster.

We must have binned thousands since I have worked there, I will see if I can find some samples to measure as it would almost be worth making an adaptor if you are a C02 buff,

The REAL fun (and dangerous due to the energy) stuff is letting off scrap aircraft slides and 60 person liferafts

ATB, Ed