Originally Posted by BigDogatPlay
If the range is a business open to the public then it being on private property isn't an issue. If it's a private club open solely for the exclusive, non-public use of members it might be another story.
When you went to the academy it would have been PC 12031(e) and I'm certain it would have been taught in the LD on point. It's now in PC 25850(b). Note the bolded, which I've added for clarity to to your situation. While many, including me, consider it unconstitutional to some degree or another, it's still the law and it's constitutionality is a subject for a different thread.
The authority for an e-check (now b-check) is clearly grounded that:
1) The LEO must know there is a gun.
2a) in public place in an incorporated city.
2b) in a public place of unincorporated territory where shooting is prohibited.
So, presuming for a moment that the LEO knew there was a gun, either 2a or 2b must also be satisfied in order for a loaded-check to occur.
There is no legislated authority for a LEO to generically inspect a firearm (without reasonable suspicion of a crime) other then the above.