300feet with 0.40BBs hard to see. :-/
To upload FPS want PSG1 spring or screw spring piece in some other spring by AEG.

Would make testing, depending on which is placed the extra spring, and will be changing the fps, you try and how many coils you need.
I have it in ATOZ close behind with about 5 coils of spring 130, 150 and wearing entire.
That is a 150 and 5 coils of 130. To have a few fps less than 550 (546fps)
Personally if you find ATOZ get this better and not the A & K
(I am afraid that this time I execution the grammar :-[)
To upload FPS want PSG1 spring or screw spring piece in some other spring by AEG.

Would make testing, depending on which is placed the extra spring, and will be changing the fps, you try and how many coils you need.
I have it in ATOZ close behind with about 5 coils of spring 130, 150 and wearing entire.
That is a 150 and 5 coils of 130. To have a few fps less than 550 (546fps)
Personally if you find ATOZ get this better and not the A & K
(I am afraid that this time I execution the grammar :-[)