Chrono with 0.20's, same as AEG's.
But yes GBB's have a different effect when moving up in BB weight.
They retain more energy because of the gas expansion and having more time in the barrel to use that pressure.
For example when I had a KJW P229 (which has a really short barrel) it would chrony 270-280 with 0.20's and 260 with 0.28's.
If you did the same thing with an AEG it would go down about 60fps to 210-220 or so.
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