Tuning Gauges?

So I got a new Umarex Readyair. Filling one of my pcp's it agrees with the gauge. It is a brand new Ninja adjustable regulator. The other 2 not so much. My Air Venturi Avenger shows 500psi higher than the digital pressure on the pump, and my new to me bottled Mrod shows 3600 when the pump is at 3000. Should I invest in some replacement gauges? I have heard these little gauges are not always accurate.

Jim
 
I would have to agree more with JimNM as I have had the small gun gauges be off by as much as 40bar which is about where you are, on a new gun before. Still for safeties sake, when in doubt, I always go with the gauge that reads the highest.

If you can find a paintball shop that fills tanks you can have one of your guns filled. Their gauge will be more accurate than anything you have and you can go from there. 

You can also buy an oil filled gauge for your pump it would likely be more accurate as well. Or you can buy a couple more gauges for your guns and go with your best average guess between what you have.