Umm, carrying live ammo with the gun is highly not recommended. Especially for casual range shooting.
Keep ammo in the original box or in a special ammo box. Keep the gun separate and locked, even if its in your car. Even worse idea is a loaded magazine, thats asking for trouble.
The only time a gun and/or its magazines should be loaded is when all of them are under your direct control. Thats not the situation when its in a case, in your trunk, on the way to a range.
Ditto the night stand. If you arent in the house with it, take the magazine (and possibly chambered round) out and store them separately. When you go to bed for the night and you feel you need a loaded weapon, go ahead and put the magazine back in then. Thats also a good opportunity to look the gun over and see if anything is wrong with it, as opposed to leaving it in your night stand for years and not knowing how well it functions.
Oh, and obviously concealed or open carry also qualifies as under your direct control, not just standing at the shooting line.