JamesAirsofterAgent

Thanks for the info. I don't actually know what barrels they are, whatever come stock in the CM16 and Cyma m1a1 lol. Its a couple open bottles (with lids) that have been kept at the back of a cupboard.

I'll be guessing they're both standard barrels.
Just make sure no dirt is knocking around in the BB containers (and clean the barrels too, for that matter).

Others here may tell you you're running the risk of doom and disaster if you don't run Geoff's Super Precision BB's anyway, so with the caveat that that is actually safe / good advice, I'd say you'll be fine.

The only problems I've had are with 0.43g bio that had been open for over 2 years, and had started to craze. One kersploded inside a 2.3J sniper and I binned off the rest of them.