Sounds dodgy to me, you shouldn't ever need to, the gas ram is maintainance free.
It's not a good idea to try and get FAC power levels this way if thats the plan?
Nice to know that you are getting your full 12 ft.lbs though! Just had mine tweaked because they do drop after time - and it cost me a 30 mile round-trip and £12 !! Pumps are sold by Weihrauch precisely for this purpose - and are £90 brand new and (hopefully) cheaper second-hand . . . . you do the maths!
Anyhow, I reckon you would need very large 'spherical appendages' in order to cock a break-barrel at FAC pressures!