My response:
Your insurance agent is absolutely correct. Your hunting equipment is not a covered loss because it's not part of your car; e.g., glass, hubcaps, tires, windshield.
Comprehensive Coverage, as the name implies, generally indemnifies you for direct accidental loss to the covered vehicle by causes other than collision. Typically, this includes loss caused by fire and theft plus other risks resulting in physical damage to
*** the insured car (e.g., storm, flood, riot, etc.).***
Here's a sample provision found in a policy:
"We will pay for direct and accidental loss to your covered auto, including its equipment, minus any deductible shown in the Declarations, other than loss caused by collision (for which separate coverage is available). The following losses are covered and not considered "collision": Loss caused by missiles, falling objects, fire, theft or larceny, explosion, earthquake, windstorm, hail, water, flood, malicious mischief or vandalism, riot or civil commotion, contact with bird or animal, or breakage of glass."
If you had homeowners or renters insurance, then you could claim under that policy - - but, not your vehicle policy.
Good luck to you.
IAAL