M9 GBBP Going "full auto"
 

Hi everyone.

I have a Jg M9 and recently put some upgrades in it including a 150% guarder spring set and a new guarder 'piston head'. Previous upgrades were an action army bearing spring guide and an action high flow valve. With the nee upgrades, the pistol shoots okay its first couple shots and all the sudden goes fully automatic. Sometimes it just goes full auto right on the first trigger pull on a new mag. With the stock recoil spring and trigger sping it shot without full auto problems. What could possibly be happening? The sears seem to be in good condition. On a side note thr gun has been sitting awhile before these nee upgrades. Thanks everyone.

Swap the old parts back in, see if it still happens.
Simple elimination of possibilities.

Forgot to add i did and it worked as it should. The blowback on the old.trigger and recoil spring is to laugh at, as in very very light.

The new recoil spring is too strong and the slide doesn't go back enought to re-engage the trigger sear.

How can this be fixed?

Put a weaker recoil spring in, or maybe try to shoot while pushing the mag upward, sometimes there is a little space between the mag's rubber and the nozzle, and a certain amount of gas is venting instead of being transfered to the nozzle.

Could it possibly be that my trigger sear spring is not strong enough and the stronger recoil spring is pushing the slide forward so fast that the weak spring cannot catch on the trigger? The gun is 2 years old and has been sitting for awhile, maybe the spring isn't doing as well of a job as its supposed to.

EDIT: Maybe this is what I need....
http://www.airsoftparts.ca/store2/in...roducts_id=976

You can try that. Does it locks back on empty mag with the stronger recoil spring? If it doesn't, chances are the slide isn't going back enought. If it does lock on every empty mag, then it might be your sear as you stated.

when it is warm out (aka not in my basement) with the stronger recoil spring it locks back if it doesn't hiccup on and just do full auto. I am going to try and get that new spring set and see how it goes. I may end up needing a new sear kit, but I cannot seem to find the sear that latches onto the notches in the hammer. If any part of the trigger would be worn, it would probably be that part.
EDIT- This is part 46