Looking for adjustable gas blocks for a pair of x39 Ar's that I'm building. I wanted the Kies adjustable gen 2's but I can't find them in-stock anywhere. Any other good options that won't break the bank?

An adjustable gas block can only reduce the amount of gas tapped to run the action. It can never give you more. Unless you're having "over gassing" issues it's not needed or wanted. My 7.62x39mm AR-15 rifles are borderline weak when it comes to the ejection cycle. The last thing they need is less gas.

I'm considering opening up the gas port in an effort to get more cycling action on these rifles. They are both relatively new and haven't been fired enough to be considered broken in. If they don't start running a little stronger I'll have to enlarge the gas port. They won't function with lighter reloads.

AK-47 and SKS carbines have huge gas ports when compared to AR-15's. No USA made rifles have gas ports this large regardless of caliber. This makes for vigorous functioning but beats the crap out of the rifles and the brass. It's not uncommon for my SKS or AK-47 to throw brass 30 feet or more upon ejection. AK's that have been shot a lot usually have hammered interior sections in the rear of the receiver where the bolt carrier has been pounding it on ejection.

A standard gas block should serve you well. PRI makes a good adjustable gas block as does JP Rifles if you are convinced you must have this thing.

Joebobs has the clamp on version in stock. I use the standard Kies in mine and it was a huge improvement, imported ammo fluctuates in pressure so much it is nice to be able to adjust it. I've done it both ways, heavy bolt carrier/ buffer and with an adjustable gas block and honestly they both work. My current build uses a light weight colt half moon semi carrier and a standard carbine buffer/ spring and it is just as reliable as my other 7.62 build that runs a heavy buffer system and xp buffer spring. i have found that most carbine length 7.62x39 AR's are over gassed.

Thanks for the information, Ihave been reading the many threads on x39 AR's and the different information can get confusing at times. Alot of people talk about the extra power springs and what not and I guess I had that confused with the rifle being overgassed, like short barrel 5.56 which requires the heavier buffers to slow down the action. So is this the opposite where lighter springs and buffers would help to keep the action open longer?

I'm also planning to run these supressed. I'm new to all of this but would the extra back pressure from the can help cycle the rifle more reliably.
I will definitely make sure to check for concentricity and any signs of keyhling first though.

ETA- I'm going to be running a pistol and carbine length so it sounds like I'm going to have to figure out if I'll be over or under gassed to find the correct solution. I'll definitely be running mostly surp ammo through it.

All mine are over-gassed, the Adjustable gas block is the way to go, it certainly doesn't hurt anything and is like $10 more.

most are over gassed.
I'll have an adjustable on mine

What is your gas port size on the barrel?

I wonder what size the port is on the guy above saying it is under gassed,

AR's in X39 Cal. run best with a mid-length gas systems...If you have a Carbine gas system then a good quality gas block is usually
a good move as they do tend to be over-gassed with the Carbine gas system...

For this reason I order/purchase my AR X39 barrels with a mid-length gas systems as they tend to be softer shooting and gain more
velocity to boot...I'm pondering a 20" X39 build for my Son in the near future...

Good luck.

I decided to try this route. happy so far.

There is probably quite a variation between barrels since it is not a mil-spec part. combine that with irregular ammo. I will say if you are shooting tulammo, that stuff is very weak where as my red army standard ammo I just chrony'd was exiting at over 2500 fps! so better to build in some leeway for yourself. I like middy's but they are hard to come by in this caliber.

http://www.blackriflearms.com/16-762x39-Mid-Length-4150-Nitrided-Barrel_p_168.html

 i have 4 SLR Sentry adjustable gas blocks on my 7.62 x39 AR builds.. they are fantastic. highly recommended.

Good to see B/A is back making 7.62 barrels, I used one of their 5.45x39 middy barrels  for a build before all the 7n6 ammo dried up. It was an excellent shooter and after putting thousands of round of corrosive ammo through her (ultimately running out of 7n6 supply) I took the upper down and there was no corrosion or wear noticeable anywhere even under the hand-guard where I didn't clean regularly. These guys are one of the few companies who can nitride parts correctly.