I have several AEGs and some are not fired for maybe 7-8 monthes. I shot in semi before store them. There is no problem at all. But be sure you keep them dry to prevent rust and mold.
I also have a "new" AEG, which I brought in 2013, but I believe that gun was out in 2007 and discontinued in 2008-2009, which means 4-6 years of storage (the amount of dust collecting inside the receiver can support me). Still no problem.
However, I found that AEGs that have been stored for long tend to have lower FPS on first few shots. After 2-3 shots then it just come back to normal.
Last edited by ccyg8774; December 28th, 2013 at 02:22..