Talk to your homeowners or renters insurance agent ....there are some companies, in some states ( insurance policies vary by state) ....that do not have a sub-limit of "Theft" on firearms --- Safeco is one in my state.
Most policies have sub-limits for "theft" only on Firearms...maybe a $ 2,500 limit. But firearms are covered, like all your property, at replacement cost - for fire, etc. Just make sure you have enough personal property coverage - for your clothes, furniture, guns, etc...if you had a bad fire.
Some policies you can increase the sub-limit for theft - to maybe $5,000...but you'll still pay a deductible ....
If you schedule your guns - by mfg, serial number, value ( you'll need to have replacement values ) ...you have to list each gun specifically / and you'll pay a premium for the value - but its not actual cash value - its always replacement cost. Bad thing about scheduling - you have to keep the list up to date /you get no automatic coverage for a new gun / you have to add it / if you sell a gun you have to remove it ...so its your responsibility to keep it up / and to keep up the values.
Most insurance companies - give you 10% of your personal property coverage on the policy ( say its $ 100,000 on policy ) then you'd only have 10% or $10,000 away from premises ( like in trunk of your car at the range )...
If you schedule the guns - it removes the sublimit / and it usually removes the deductible.
Rates vary a lot by state...check with your agent.
NRA's insurance may be all you need - they have info on their website / and it would keep a claim off of your homeowners insurance if something comes up.