The word "shall" is a key component of the second amendment. My attorney explained to me the difference between "may" and "shall" years ago.

"May" indicates flexibility, whatever is being referred to may be changed at some point and its enforceability is also subject to change.

"Shall" is concrete, it is an absolute. There is no flexibility when the word "shall" is used. Therefore, "the right of the people to keep and bear arms shall not be infringed" is absolute, so laws and ordinances that restrict this right are unlawful and unconstitutional. Getting the courts to actually uphold this portion of the second amendment is difficult as so many people want to alter or reinterpret the amendment.