I use Lockton Affinity. $250 deductible. Covered home, away, in transit, and acts of terrorism. No serial numbers, but firearms over $2500, they do want listed. For me, the policy and coverage was the decider. It's a little more than Collectables Insurance, but for me it was worth it.

Collectables is about $8/1K and Lockton is about $11/1K annually. I did not insure to full value with Lockton, because I have some through homeowners, NRA and my Instructor Insurance as well.