[kmeyer]

I have a TM upgraded hop unit and a TM stock one. The stock one is in my VSR and it works well but when I try to put the upgraded one in it then the bbs will not feed unless I push on the bottom of the mag. I haven't the foggiest idea of what could cause this. I even had an old VSR that I bought used which the upgraded unit came with and it worked perfectly in it. Also for that matter what is the difference between the stock unit and the upgraded one? They seem to be exactly the same in every way except the color.

 

[awagg]

So basically the opposite happened for me. The mag just needs to be a little bit higher to feed. It's good to take a little putty, and fill in the gap partially, making it raise up.

Also, yeah, they are the exact same, according to some people, if you have the TM VSR 10. However, the JG hop up has bad tolerances and you will find an improvement.