Flat hop.
 

Hey just wondering when doing a flat hop should I be removing the bridge on the barrel or not. I looked at post online no one says either way. I've been trying to donit with leaving the bridge in but the hop up never seems to be functioning properly the bbs go everywhere.

Leave the bridge.

Ok them do I have to widen it cause to get the nub to fit into the window it has to be so tiny

You don't have to do anything.

Remove mound
Turn bucking 90 degrees
Install appropriate flat nub or eraser
Call it a day

Likely hood of your gun shooting exellent afterwards with no further adjustments are quite high.

you need to remove the nub from the bucking, you also need to remove the lock ridge from the bucking,

Most flat hop nubs although claiming to be drop in do need to be cut down length wise, a particular way.

As much as I hate to do this amped airsoft does have a half decent flat hop guide, its not the end all to be all guide, but it will show you how you should be cutting the nub.
https://www.youtube.com/watch?v=ZqXbVQshNpI

I facepalmed a little bit when i saw the title of the video series. This was a good guide though

So sort of went against everything you all said and widend and lenthened the window just a goose hair. Flat hop works perfect now thanks