What's inside your Chinese Beeman?

This one is a Sportsman RS3 - The one that comes with 2 barrels.

It's low on power - 7.52ftlb in .177 and 8.15ftlb for .22.

I had it apart yesterday and took some measurements.

I'm in the UK with a sub 12ftlb power limit so, I was wondering if you all have the same set up?......... Same sized spring and a sleeve to reduce the inside of the piston?

Also, what size is the transfer port on yours?

Thanks in advance 👍🏻

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