Firearms and Ammunition - As introduced, requires any person or entity posting signage prohibiting the possession of firearms on a property to accept custodial responsibility for the safety and defense of any person authorized to carry a handgun, while the person is on the property; mandates that any notice or signage posted forbidding firearm possession also contain language stating that a person authorized to carry a handgun is under the custodial responsibility of the posting person or entity. - Amends TCA Title 39, Chapter 17, Part 13.