There’s one of those on my .270. I fill it up before I leave the house. When I leave the truck I load the gun from that stock sock which leaves it about 1/3 full. When I unload I fill it back up. That’s an easy way to know if the gun is loaded or not (blind magazine) if I shoot, I pick up the empties while waiting for the animal to expire calmly, I then stick the empties back in the sock and reload the rifle. It’s a lot more convenient than other methods, and the beauty of it is that if you put it there before you leave home, you know you have ammo when you get to your hunting spot.
The comments on muzzle discipline... if he uses my method then he has verified the gun is empty (full sock, 2 empty cases in the sock indicating he shot twice and unloaded) so it is nothing more than an expensive piece of iron laying next to him. An open action would have been better, but I am not faulting the man here because it matches almost exactly what I would do, and I know that what I do is safe.