Panther's range is ~220ft so you should be able to zero your gun pretty easily, unless you're using that tiny indoor one the rentals and paintballers seem to use. If that's the case, use the one by the parking lot the regulars use, any one of the guys there will help you out if you need it.
Get someone to spot for you while you shoot, helps out. There's a tiny diamond plate at the end of the range I aim to hit consistently w/ my G3 before I'm happy w/ the hop up setting.
Just your friendly neighborhood narcissist gearwhore.