Here is a little back story:
A few weeks ago I purchased one of Kennyd's 5000 psi gauges to check my hydraulic pressure because the FEL seemed a little weak. I ran three tests, 2000 psi, 1975 psi and 2000 psi were my results. I happened to be at my dealership while purchasing a Frontier rotary cutter and got shooting the bull with the service manager. Looking at the tech manual there are a few relief valves on these tractors, so I was really questioning which one to use to make the adjustment. So Tom (service manager) says to me "you know Pat, if you word that the right way I can adjust that under warranty". I was pretty quick on the take this time so I said "okay Tom, my FEL doesn't seem to be picking up as much as it should", he said, "now we have a problem, I'll take your word for it on the diagnosis and send a guy up to your place first chance I get"
Tech stopped today and adjusted the main relief valve, he said his initial test with his gauge was only 1900, adjusted it to 2200 psi on his gauge and it is reading 2300 psi on my gauge. If anyone in New York needs a great dealership I would highly recommend Cazenovia Equipment Company, even if they are not your closest dealer it will be worth the drive.
Now the only question is, who's gauge is correct
Either way, 300 psi jump in hydraulic pressure should be more than noticeable IMO.