Where do you keep record of your firearm inventory?

Good point on the ammo, what with prices being all over the place even still today.

All I have at present is a 5x7 hand written tally sheet in the .cal..50 cans--so I don't have to dig through them looking. My cal..30 cans only ever hold one caliber at a time.

Spreadsheet (Apple Numbers, as it happens) with regular printed out back ups. I also record when guns leave my possession.

I use Reportit for civilians from LEADS Online. https://reportit.leadsonline.com/

allows me to update, store info on the item (not just guns) and record serial numbers, model numbers and upload pics of the item in case they are stolen, or lost in a fire.