I'm sure that the kraken is basically a cyma ak so anything that would bump that should work in yours. Maybe a m120 or m125 depending on how good the airseal is. You could just get a really good airseal and put a m100 in it and crank 400. Ive seen it happen. A m120 is probably your best bet though.

I am doing a triple video comparison between the kwa ATP, echo 1 timberwolf, and the APS ACP. So far i havent seen many problems but the timber wolf does have mag problems but its due to a weak follower as they keep breaking. The ATP has a weak hammer spring issue as it is clearly not strong enough to provide a solid hit to the gas valve. The ACP is the only one without issues so far and seems the most promising for a glock style side arm. If the ACP wasnt CO2 it would probably be the best choice as the internals would have much less stress put on them using propane. Ill have to keep an eye on that barrel issue now.

just checked out your channel and that intro you have on your video is crazy, very cool.

welcome its good to have you here. Im still going to attempt to play outdoors just due to the size and fps restrictions you get when playing at an indoor field. I almost feel no difference in temp when it comes to the actual field area at an indoor airsoft place. Stay hydrated and happy airsofting.

SOLD FOR REAL THIS TIME

So im thinking about selling my g&p woc. Depending on the offers i may just keep it but m4's are boring to me now. So starting off with what's included; the WOC, a g&p pmag, and some extra parts are what you're getting. Externally my WOC has a g&p magpul lower receiver and a vltor MUR upper. On the receiver i have put a g&p steel selector (non ambi) and g&p ambi mag release. The stock is a g&p vltor style one (emod i think) and the stock tube is a 5ku vltor engraved one with a qd sling plate with mount. The grip is a magpul miad and the rail is 7 inch DD lite rail. I've put a vltor front sight and troy rear sight on it and the barrel is a 14.5 g&p steel barrel. Last thing is the front pivot receiver pin is a ra-tech magic pin so there is no receiver wobble at all.

Now for the internals! This has the standard g&p firing block, g&p steel firing pin, g&p steel bolt catch, g&p steel trigger, g&p steel trigger sear, g&p steel hammer, g&p steel buffer lock, g&p metal hop up set and inner barrel, g&p standard charging handle, and g&p aluminum buffer. The bolt carrier is a 5ku aluminum vltor and the bolt (nozzle) is a SA nylon fiber one. I will include a 5ku metal nozzle and locking plate as well. Some extra springs and parts will be included as well. Im asking $350 plus shipping. Price lowered because while i was running a drill with this guy the new plastic nozzle cracked at the tip so now im down to using the metal nozzle. The metal nozzle does not produce a seal near as well as the plastic one so the oring needs to be replaced with a thicker one to get better gas efficiency ATM it sucks. oring size is either a 2.4mm or 2.5mm with a 12 or 12.5mm inner diameter. Cash is king here. Feast your eyes on my m4 now. Ive also posted this on gasguns.info so i can cover my bases.
 

not sure why i didnt bring this up before but you can also ask around the gas guns info forum. Alot of those people are gas gun gods and they can provide alot of help and information beyond just getting your gun up and running.

thanks for the info!  sounds like a great place to start going to before it gets crazy hot