GHK AK dropping BB's and getting bad range

[Sentenced2Burn]

So I thought I'd start a thread for a friend and see if I could glean some information on a problem we've both been encountering on a brand-new GHK AK. As far as I'm aware, these things should be shooting great right out of the box without issues such as this one:

It will fire and cycle fine 100% of the time, but the range is absolute garbage (as in something is clearly wrong with it), with the first few BB's flying fairly straight and decently far, but the following BB's losing tons of hop and dropping to the ground.
After looking at the hopup design and disassembling many times to learn more, it appears as if the hopup "free-spins" and has no lock on it at the minimum/maximum values. We have tried teflon taping the housing underneath the hopup wheel to make sure it's not loosely floating and spinning/adjusting itself, but to no avail. Different buckings (hard, soft, stock, 75-degree, 60-degree, W-hold) have made little difference in the overall poor performance.


The hopup unit seems to be the problem after trying different barrels (stock and TBB) as well as different buckings and nubs. I have yet to get him to chrono-test it to find out if it is losing compression, but I have thoroughly examined the nozzle and blowback housing and made sure there are no tolerance issues in the seal formed there. I have also teflon taped the barrel and bucking to ensure no compression is lost at the hopup point.



Can anyone here weigh in on this? Did we get a lemon, or is there another simple cause that we can fix ourselves? I've heard of the aftermarket hopup chambers but they seem to solve a different issue entirely and require filing in order to make it shoot okay, and from what I've been told and read online, the GHK AK series is supposed to perform solid right out of the box.

Thanks in advance for any insight.