Out if the box, AA set them up at approx 10.5 fpe IIRC. They can be tweaked and mine runs at 11.3 with AA Fields in .177.
The difference bewteen 10.5 and 11.3 is minimal.
Your best bet is to buy a Chrono from the sponser of BBS, JSR in Keighley. Then you will always have the gear to test the power of your rifle and keep it legal. Also buy some Bisley Mags to test the power (heavy pellet).
(Put the tin of free pellets in the post Ed )
You will not find on here details of how to up the power on any rifle, so a trip to your local gunsmith is a good starting place.
AA 410k, 3-9X50
FN19 Hawke, 6-18x44
AA S200, 6-24X50
S10, 8-32X50