Get back and let everone know what you did.Would be great info for alot of gun owners here.

I was in the insurance business for 20+ yrs(Claims).Handled a few gun losses.I would go to your insurance agent on the Renters Policy.I've never seen a policy without a standard coverage on Firearms.If you have a large collection talk to agent about "Rider" as someone mentioned.
Your renters policy should be the cheapest way to go. Good Luck