"...don't choose to insure them beyond whatever my homeowner's policy limit is..." If you become the victim of a crime or tragedy, you'll get whatever the insurance company thinks your firearms are worth. Your homeowner's policy doesn't include 'replacement value'. Insurance companies work from their own 'Blue Book' that has nothing to do with reality.
Insurance companies think everything loses value over time. Firearms generally, don't. Even late model commercial hunting rifles retain their value fairly well. Not in the short term, but certainly over 5 or 10 years. In any case, it'll cost you more to replace, say a Rem 700, than you paid for one 5 or 10 years ago. Far worse over a longer term.
Ammo, reloading supplies and the 'drawer' won't be covered.