I have a kraken too =.=
Nylon bushings. And after about 5000 rds, they were wobbling like crazy in their sockets.
The plastic body cracked at most of the holes for the screws too. Rather than buying a new kraken, I'm suggesting someone purchase a used JG that will probably have had metal bushings installed, maybe a metal spring guide, and had preventative maintenance anyways.
Also the air seal is poor enough that it leaks even if I push the nozzle all the way against the cylinder head.
The $200 difference isn't that much really...
The spring(keep in mind the shitty air seal with a horrible clear nozzle and piston head o-ring) was shooting 380 even in around -15 weather.
EDIT: I stand corrected. Forgot about the CM035 ><. However it seems some new ones are still coming out with nylon bushings. Hell, I wonder if they have gotten rid of that shitty clear spring guide.