Non disclosure of WHAT..exactly. Smoking is an exemple in Quebec, because you get a discount if you're a non-smoker. If you say you don't smoke to get a better price and you DO smoke, you can bet your last dollar the insurance company won't pay if a fire destroys your house and the direct cause is a smoker's accessory (cig, match, lighter). Fireplaces are another, because if you have one, you must declare it and pay more for the fire protection. If you don't, to save money..HA HA caught again, we no pay !
I looked at my homeowners insurance and found nothing to indicate I should declare reloading or firearms for that matter. If I want specific protection for my "guns" then yes, I have to specify them, pictures, make and caliber. Same for specific protection of jewelry. Otherwise, I'm automatically covered by a blanket amount ( varies from company to company) for the firearms and the jewelry.