WE-Tech G39 Gas Blowback Rifle Factory Spare Part #91 - Firing Pin Delay Stop

"Apparently this fits the we m4 and l85 as well, going to buy more just in case.

"If your G39 is half stroking and acting funny while firing (fires a bb, then half strokes some shots, fire another, half strokes, etc.), then you will need this part. This part feels more sturdy than the pot metal, but if it does break, I know where to get more.

Pros:
Fixed my gun

Cons:
Chance of breaking again