Others have answered your original question. Here is another angle to look at it from. For some of us it is about more than could it go bang, it is simply illegal. Here is the wording of a regulation in Colorado “It is illegal to have a loaded (in the chamber) rifle or shotgun in or on any motor vehicle. Muzzleloading rifles are considered unloaded if the percussion cap or shotshell primer is removed, or if the powder is removed from flashpan. It is illegal for anyone to have a loaded electronic-ignition muzzleloader in or on a motor vehicle unless the chamber is unloaded or the battery is disconnected and removed from its compartment.”
I wouldnt want to argue semantics with a warden or trooper on wether an open bolt with a round “partially” loaded in the chamber is gtg or not. We also obviously then can’t discharge a firearm from a vehicle legally either so that takes care of that. I’m sure other states see it differently.