[Statua]

The x won't affect the fps. The inner barrel is the same diameter of a cylindrical file I have so I filed the inside of the pen tube. It's perfectly smooth and flush with the inner barrel. There is at least 1 cm between the inner barrel tip and the outer barrel so the pen actually goes inside the outer barrel, ultimately making the path for the bb clear of debris. The only thing that would cause a fps drop would be the spiral formation of exhaust holes I made in the pen to reduce the sound.