On the way home from the delivery room at the hospital with your new born baby, do you walk in the house, and wonder where you are going to put little Johnny? Most likely not, as you have been planning, and have a baby's room all ready.
This is blunt, but if you have a gun or guns, and have no safe or safes, you have no business with guns.
A locked tin cabinet is not a safe.
Every gun not on your person, needs a secure safe for storage. No exceptions.
Safe needs to be UL rated for fire and burglary. It needs to be heavy, and bolted down.
Ammo also needs locked up, and it should have a separate safe, that is ideal.
Have five guns and no safe? Sell four of them, and take the money and purchase a safe.