Mid-Caps and Low-Caps I empty completely, I have a few hi caps which I let spit out back into the bottle if unused, but those springs are 10feet long and made of unicorn hair so I think once they start dropping or misfeeding they're gubbed, so maybe worth continuing to empty if you use. Gas mags, I keep a bit inside and regularly (once/twice a month) check the release valve on the back is under pressure. I’m always happy to be corrected, but most legit airsoft gas has some silicon based lube in it. (Hehehe, I said lube….)