Storing guns behind the firing line, especially at a public range, is generally not a good idea. I can't tell you how many times I've seen people try to do this, or try to uncase guns back behind the line, and they end up sweeping everyone on the line. At one point some dude did this with a loaded .270 bolt gun, cased his gun behind the line, negligently and inadvertently pulled the trigger, fired a round down the firing line, through the trash can, ricocheted back and I believe hit the opposite end of the firing line. Thankfully this was 3-4 feet back from the firing line, indoor range, and no one was hurt due to pure dumb luck. I find that the average person is, unfortunately, way too unsafe to allow handling of or storing firearms back behind the firing line. As long as there is room to do so, I usually recommend people store their stuff on the shooting bench, on the ground at their feet, or anywhere else right at the firing line if possible. Sometimes it's not possible, and that's cool, it just means you have to be that much more focused on safety and make sure you don't become complacent. I'm just speaking generally here about all of us.