To answer which BB weight is best for AEGs, Cisco of Airsoft GI does a BB Shootout video. For us, it is what we find more comfortable to use in shooting is what you should go for... "We get asked what weight BBs to use for AEGs by beginners quite frequently, so we've shot a video to show you what's what!

We performed the test at approximately maximum effective range for the stock G&G Combat Machine we used for the trial - approximately 250 feet or so. As you can see, there's a sweet spot to be found for stock guns! The .28 BB was able to punch out accurately without causing complications to the hop up unit. What BB do you run?"