Hay guys! I recently bought a Madbull Surefire Mini 5 suppressor, and the compensator that is suppose to screw onto the barrel, has a rear end that overlaps the barrel before it screws in. That whole where the barrel is suppose to go in, is 1mm too small. I watched videos on people installing it no problem on their barrels, so I am assuming because I have a GBB, its milspec and the AEG outer barrels are probably a tad thinner?
So I tried sanding it down with 60 grit sand paper, no go, and also tried filing it down, no go
Any ideas?
The hole on that compensator >

It screws on, but cant go in further due to it being smaller.