greeting , I have a Benjamin Cayden .22 it is a non regulated pcp, It fills to 3000psi , and I use a compressor to fill. my question is can I fill the gun at any point ? or does it need to be shot down to say 1000 psi? I was told that non regulated guns have to be shot down and shouldn't be filled in the middle of a shot string. I question this ,.. but don't know for sure . I could use some experienced clarification Please.