i did not lose the spring, but the spring might not have enough tension to push the piston sear all the way up.vindicareassassin said:You took it apart, didn't take any notice it was there, and re assembled the trigger, and have now lost it..... havn't you? :
Not sure even where you would start to look for a new one :-/
You could try a supplier that stocks TM/BAR parts, or even a store selling car parts as they would have a selection of springs that might be the same/similar.
Alternativly you might want to put a WTB or WTT for some one who has swapped out their trigger for a Zero trigger etc.