Technically still a 22lr

Hmm, so I’m thinking anyone who would like to experiment with this without building/modifying a custom action could just try it in a Thompson Center Contender with the firing pin selector set to centerfire. Furthermore, if the charts I’ve read are correct, they made bores in 12 twist and 16 twist.
As for the gent contemplating modifying a Rem 580 series, I’ve heard of it being done and chambered to .22hornet, but didn’t see the gun. Fellow said it did crack a couple of the locking lugs. Also, I’d recommend lapping the lugs for full engagement (you’ll likely be surprised how erratic it is), but remember to check headspace afterwards.