Hatsan's rams are only supposed to be rated for 150 bar or roughly 2175.5 psi, but I'm guessing you already know that. I'd also guess Hatsan had their reasons for it and designed all the moving parts to be able to handle that much pressure if someone decided to stretch it to their max listed pressure. Next question is how much extra did they factor into all those parts if someone decided like you did to jack that up like you have to 175 bar or roughly a little over 2538 psi. You'd have to ask Hatsan how much pressure the seals in that gas ram are even designed to withstand before they blow out. You mentioned the velocities are holding, now how much harder is it to be accurate with that much power behind the trigger?
You also don't seem to have factored in way more stress on the cocking arm, seals, trigger sears, receiver, the screws holding that action in the stock. Sooner or later all that extra pressure and the force required to cock it not to mention the forces generated firing is going to make something break loose long before it was probably meant to.
You want that much power, my suggestion is go buy a PCP.
