330 on .20's (1 Joule) and you should be fine for pretty much every indoor/cqb venue.
As for the Kraken, I've heard the spring settles pretty fast and you'll end up around 370-380 on .20's usually. However your best bet is to get a lower rated spring.
ಠ_ಠLess QQ more Pew Pew
READY TO >> RACE