I have mine covered on my home owners. I think up to $2500 is automatically covered on my Statefarm homeowners policy here in Texas. I pay like $6 a year extra to cover up to $5k in firearms. They won't go above $5k. After that, U have to insure guns seperately at a prorated fee depending on their value. And, that would only cover theft and not fire.
But, if ya have under $5k worth, ya need only worry about the extra few dollars a year. Now, this is Texas - Statefarm operates a bit differently in each state due to different laws in each state.
I was told I just needed the receipt and the owners manual to make a claim. I have the receipts and manuals locked up in my bank box.