44 Henry rimfire

[Phosphorus32]

https://www.proxibid.com/REMINGTON-UMC-44-HENRY-FLAT-RIMFIRE-CARTRIDGES/lotInformation/64423559&scrollLocationOnCatalog=1124

Ammo has gotten a bit pricey lately. $216.90 per round (plus your resident state sales tax and insured shipping)   

[running-man]

Laugh, in this case, the box is probably the main driver in the price as individual rounds look to run $25 on the broker https://www.gunbroker.com/item/910748162

Still, that guy probably has one heck of a collection!

[Greasemonkey]

Here is an original Henry 44 rimfire rifle locally for sale... just $27,500. I've looked at it.... from a distance..

https://www.gunsinternational.com/guns-for-sale-online/rifles/henry-rifles-antique/the-henry-rifle-1860-44-rimfire.cfm?gun_id=101729823