samyang .50 power tune advise

Samyang .50 dragon claw dual reservoir power tune.
I put lead inside the hammer about 100 gr= about 10/15mm of height it made the standart spring get more compressed when assembeled and made a new transfer port whent from the standart 0.290 inches(7,39mm) to a new one with 0.322 inches (8.18 mm) with this I didnt gain to much power from 663 fps (178gr roundball) to 689 fps (178gr roundball) but for eache shot the power would boost more fps and for a total of 6 shots then it went down. In the standart mode the power was a little bit less and with eache shot the power would come down.
with this tune it´s all I think I can get, for more I would have to take out the valve and cut some coils of the inside spring, as I learned by the power tune for eache shot the power would incress meaning that the air inside the reservoir and the spring was batteling against the hammer and when less air from eache shot was wasted the hammer could strike further letting more air out.
Need Advise in the dissasemble of the valve:
I want to take the valve from the rifle and cut some coils of the intake spring valve to help the hammer in the first shots were the power is lower due to the hard valve spring and the high pressure in the reservoirs fighting the hammer strike.
Thank´s and sorry for long post.