I don't subscribe to the saying "ALL GUNS ARE LOADED".
Maybe because you are only using part of the saying?
its "assume (or treat) all guns as loaded until you are certain otherwise"
Meaning, until you, personally have verified it is empty, treat it as loaded for safety.
I don't know anyone who would argue that a gun with ammo in it (chambered round, or not) isn't "loaded".
That is just basic common sense.
Where it gets confusing is the state definition of loaded when the common definition is different.
This most often is applied during transport.
Some places use the common definition, rounds in the gun, loaded, no rounds in the gun, unloaded.
But some places use a MUCH broader definition. In those places, a gun with NO AMMO IN IT can legally be a loaded gun, and you can be prosecuted for it.
If the gun, and the ammo are within your control (meaning within reach, or within the same "room" (passenger compartment of a car or truck for example)
the fact that you COULD get the ammo and load the gun legally constitutes a loaded gun.
And there is virtually no defense. IF the conditions specified in law are met, then no matter your intentions, or what you THOUGHT was ok, buddy, you are guilty.
So, the real problem for shooters isn't when is a loaded gun a loaded gun, (because it always is), but when a physically unloaded gun IS A LOADED GUN in the eyes of the law.
So, some legal definitions (the sane ones) rely on the actual physical configuration of the gun and ammunition. Others rely on the POTENTIAL configuration of the gun and ammo. VERY IMPORTANT to know which does which, where!!!!