I don't know how "rare" they are but I have 2 that, to my knowledge were never cataloged.
1. a 1 of 100 Ruger Alaskan in .375 Ruger. This is one of the first released, no barrel band sling swivel, no brake just a tidy little "carbine".
2. a Browning LH A-Bolt SS in .280. Killed several deer with it but just don't use it anymore. Truth be told I wish the barrel was marked .270.


Bore size is no substitute for shot placement and
Power is no substitute for bullet performance. 458WIN