My 700 mm Panthera starting about two weeks after it arrived - leaking 100 bar per week. I called FX and their customer service team and they gave me a repair authorization allowing me to send it back at my expense. I did and it arrived back about a month later with the regulator gauge severely smashed and still leaking.
To make a long story short, FX issued a call tag and it went back again, this time at their expense. It came back about five weeks later, seemingly fine to this point.
In fairness, FX couldn’t have been more gracious and responsive. They fixed the problem. The rifle is so unique in terms of power and accuracy, it is worth it and I truly appreciate that they stepped up to the plate and handled the issues.