If it was offered, a 8x57R would be interesting, but then every caliberr is interesting in some way. A .308 has less body taper, so a 8x57 chamber may not clean up right. :You would have to rebore and rechamber something like a .223 barrel, or do the stub route. From the standpoint of the bean counters, all "needs" are covered by .223, .243, 7-08, .308,(and or); 30-06, and 45-70 .22, and .357.
I do wish there were more offerings in bottle necks over .30.
And while we are wishing for improbable chamberings: .33 WCF, .348 Win., and for real, .338 Federal. Given enough time and money, I would have a handi in every one of the .308 family, every 30-06 family, the Mauser family (.257 Roberts), and all the 45-70 based brass.