The city could start by obeying the federal Constitution's Second Amendment, and Article 1, Section 21. of the PA state constitution.
“The right of the citizens to bear arms in defense of themselves and the State shall not be questioned.”
"Shall not be questioned", but you have to beg the Chief of Police for permission to bear arms, including long arms, in Philadelphia, (or the Sheriff elsewhere in the state)
But only for permission to bear a handgun. Outside of the City of Brotherly love, long arms do not require permission.
Except when you might need that long gun the most.
From the NRA/ILA summary of PA gun laws
It is unlawful to carry a handgun, rifle or shotgun upon the public streets or upon any public property during an emergency proclaimed by a governmental executive unless the person carrying is actively engaged in lawful self defense, is licensed to carry firearms, or is exempt from licensing requirements. It is unlawful to carry a handgun, rifle or shotgun upon the public streets or upon any public property in Philadelphia unless the person carrying is licensed to carry firearms or is exempt from licensing requirements.