In my safe I use the top shelf for my handguns.
Below the top shelf I took out all of the internal racks and with all my rifles and shotguns with gun socks on them to keep them from getting scratched, I stack them half with barrels up and half with barrels down.
You can get up to about 30 long guns in a safe this way and my safe is a standard size safe, there are problems if you want to get a rifle from the back of the safe you have to take out most of the rifles, and most of my high caliber rifles have the red dot scopes and regular rifle scopes taken off with quick detachable mounts like LaRue. It is more convenient just to buy a second safe but you will be suprised at how many firearms you can get into a safe this way.
Life Member,,,Military Order of the Purple Heart, Veterans of Foreign Wars, American Legion, Amvets, Disabled American Veterans, 173rd Airborne Skysoldier Association, National Rifle Association, Member,,,IDPA, USPSA, Iowa Sheriffs and Deputies Association,,Website http://www.handgunholsters.net