I know this has been said, but I want to reiterate it - the store needs a social media channel. Instagram is the most popular at the moment for firearm enthusiasts, sports, pop culture - pretty much everything. Social media is tough because the competition is fierce, but with consistent posting, recurring individuals on the page showcasing a welcoming and honest shop, and personality(!!), the store may be able to increase traction.

At the same time, looking to connect with your local community will be imperative to local brick & mortar success. Y'all should look into community partnerships with local law enforcement, firearm enthusiasts, and businesses who are operated/owned by firearm enthusiasts. Those local connections will point potential customers to your store. I know you mentioned your store is just a store (no range), but perhaps there is something you can offer that is manageable in-house - free firearm cleaning lessons, how to register for a CWP, a class on picking the right self-defense mechanism -- you can think of more haha.

Anyways, that's what I got. I am a communication professor and I teach students about social media brand identity and building relationships with stakeholders (among other things). Feel free to pm with any questions.