Welcome to this board alfalfa
When I think of bolt-action rifles, it reminds me of the 1950s and 1960s. Buy a modern muzzleloader and the link below offers you a wide choice/selection. The 2nd one listed below is an entry-level ML, called the Impact. Read about the other four T/C models and let us know which you find most appealing.
These fall/break-action muzzleloaders listed on the page below are the most modern and conceal the muzzleloader ignition systems the best. Sealing ignitions is #1 with me, when buying a muzzleloader. #2 is buying something with the least amount of large moving parts.
That's why I rule-out bolt-action muzzleloaders like the recommended Knight Ultra Light. It's a top-tier muzzleloader, for sure. But it's a bolt-action and the reason why Knight sells so little products these days. The #1 and #2 selling modern muzzleloaders today are either fall or break-action MLs. If Knight invested more heavily in fall-break action MLs, they would triple their business.
If I was in my 70s and wanted my kids to continue using my guns, I'd want them to have the most modern available today. If you agree, then scratch the idea of buying a bolt-action ML.
https://www.tcarms.com/firearms/muzzleloaders