Hi guys here for sale is KJW M9 GBB as you can see by the pics it’s in good condition, all metal construction wise, it’s not working correctly though vents all its gas on the first shot. I’ve stripped it and gave it a check over & clean put it back together with some lube and it made no difference, all the internals look fine so should imagine it will just be a worn spring or seal so will be a cheap fix, just no time to fix. 
Looking for just £30.00 collected from Birmingham or £35.00 posted.