I had my own insurance agency in the 90's. Every company that I ever knew of had specific limits for firearms, jewelry, antiques, musical instruments, etc.
Firearms had specific limits allowed for theft unless they were scheduled on a rider for an additional premium. However, firearms were covered up to total policy limits for loss due to fire, tornado, etc.
The reason behind this is to prevent dishonest insureds from suddenly having thousands of dollars of undocumented firearms, jewelry, antiques, etc claimed after being lost to a burgler.
As far as Dr.s' asking about firearms in the house, you can thank the current resident of the White House, Bloomberg, et. al.