We HK416/SOL/888 Full Auto Keep Firing
 

Hi,

I just acquired a We Hk416 as my first GBBR from a trade..owner said he put in a RA-tech trigger box and included the stock trigger box as well..

Semi works fine and crisp..didn't have a chance to go to field chrono yet..I don't have one..

Full auto goes crazy and start fire on it's own after 3 rounds or so...I have to squeeze the trigger again to stop it..

It's not a big deal for me because I only play on semi..however I still want to know and maybe fix it if i can...

I would check the setup of the trigger assembly. Since it came with two, it's obviously been taken apart. It could be that the trigger mech is sticking, so it continually cycles until you hit the trigger again and it frees up.

Cycle the action dry without a magazine and check that the safety works. Switch to semi auto, pull and hold trigger and cycle the bolt back making sure the hammer resets and does not follow the bolt home. Switch to full auto and pull and hold the trigger dropping the hammer, when you cycle the action back the hammer should reset and stay back until the bolt is a few millimeters from closed.

Function test will let you know if you have gremlins in the lock work.

I suspect worn sears in the case of the OEM trigger box causing the runaway or fitment issues in the case of the aftermarket one.

Hope this helps

good luck!