WE GBB Blowback openbolt problem
 

My bolt locks back and jams back while firing. As soon as lower reciever is removed bolt slams forward. Bolt catch does not correctly catch and only fires on semi auto when bolt catch down???

Any help would be greatly appreciated.

Thanks in advance

Kenny

Check the lower reciever trigger group for damage on the hammer.

It seems when the bolt comes back on full auto the hammer doesn't arm properly and that's why it is jamming. There are impact marks on the back of the hammer as well as the front end of the bolt.

Then check your auto sear to see if the springs are in place, or if there is any wear marks.

Anyone got a solution on this?

Got the same problem on my scar. it's intermittent and I can't seem to figure out why it would do this.

The problem lies withing the lower receiver trigger assembly. Do any of you who experience these problems use ra-tech lower reciever parts? Something within the hammer, sear, and springs lies the problem. Either that or the bolt catch is deformed or something weird.

This started happening on my scar a long time ago when I used ratech parts. The problem went away when I purchased a new trigger group altogether.

One way to test this issue with the hammer is:

-Pop the gun apart

-Use your thumb to cock the hammer manually

-After hearing it click and lock into place, push
down on it even further and see if it locks even
lower a second time.

-If it does lock a second time, something is worn away
or not aligned properly.

To the OP, is yours also a SCAR?

This is a very common problem on the SCAR (I think it's been fixed in the newest version), and is caused by the bolt carrier going further back than it should, and getting stuck on the hammer (hence, when removing the lower receiver the whole bolt assembly will go back).

My recommendation for the SCAR is get the GunsModify Steel Bolt set (it's excellent, your gun will lock back every time, solves the issue you're having, will give you greater recoil, and will virtually last forever).

BUT if you want to DIY the issue you're havin' (but without gettin' any of the extra features), you need to add some extra material to the rubber buffer behind your recoil spring, something like a piece of credit card, with two holes, placed in-between the buffer and the back of the recoil spring. That should add enough extra forward distance. The GunsModify actually comes with a longer plastic cylinder for the recoil spring, so it's essentially the same.


Fox.

To me, I would try to fire the gun without bolt catch see if that solves the issue on regular cycling rounds

strike marks on the back of the hammer? sounds to me that the carrier travel is too deep.