True but states have mandates on many things and require that in order to operate or occupy you need insurance, I was just checking around to see whats out there and found a couple of NRA endorsed firearm insurance programs, this isn't a milli and not specific to the PA requirement but I think it's a good thing to have regardless seems beneficial if as a gun owner I screw up.
Excess Personal Liability
Certificate of Coverage
"The NRA Endorsed Insurance Program is one of my favorite NRA benefits! "
Excess Personal Liability provides NRA members extra liability protection when they hunt or shoot.
Most homeowners' policies fall far short of adequate protection for liability claims. With Excess Personal Liability, you'll protect yourself against liability suits up to $250,000 for any injuries you unintentionally cause while hunting or trapping on public or private land.
The National Rifle Association Endorsed Excess Personal Liability plan also protects you while shooting in competitions or at private shooting ranges.
Provides coverage for bodily injury or property damage caused by the use of a firearm, airgun, bow & arrow or trapping equipment when you are legally obligated for damages.
Pays most defense costs in addition to liability limit -- even if lawsuit is false
Liability Limit Options $100,000 up to $250,000
Optional Self-Defense Coverage available
NRA Endorsed Insurance Program Excess Personal Liability