M4 mechanical trigger stiff
 

Hi, my trigger doesn't depress in semi but does in full auto although it's a little stiff. I know theres a spring that pushes the trigger back out after it is pulled. Before I buy the part and open it up, is there anything else it could be? Selector switch? Thank you.

Remove the gearbox from the receiver and check that the trigger is moving freely when the selector plate is pushed in the appropriate spot.

If that is not the issue then check that the fire selector is aligned with the selector plate.

Thanks. I took the gun and gearbox apart and there is a very small piece broken off the trigger and the trigger spring appears to be slightly bent. (I can post a picture later today).

It's a version 2 gearbox, so will basically any plain m4 trigger sold by stores in Canada work? I've seen a couple for $10 or less.

The triggers are 'supposed' to be universal but some fit better than others e.g. installation is more stiff but yes generally any will work.

Pay an extra couple of dollars and get a steel trigger.