The prob with that argument is that every state already restricts gun rights in some way and has a police force much better armed (and more rights) than the public. Not infringed would mean no regulations on it exist yet every state has them.
“Reasonable restrictions” would likely substitute “shall not be infringed” and many compromisers would likely be willing to sacrifice that for some other issue.
every state already restricts gun rights in some way
So you are afraid that what is now happening in "every state" will now simply be explicitly authorized by the Constitution. What difference does it make to your right to own or bear a weapon that the damage is done one way as opposed to the other?
A basic impetus for convention of the states is to stop the unconstitutional incursions into our liberties done every day by the Congress, the courts, the deep state. You acknowledge that is also obstructing our right to own and bear arms. Are we to forfeit all chances of stopping this unconstitutional path to tyranny and obstruction of all our fundamental rights to favor the illusory fears concerning guns?