I see that Ruger now makes the rifle chambered for the .300 Blackout.
6.5 Creedmoor is latest greatest surpassing the Blackout for rag time, is it short enough for that rifle?
The Remington 750 is no longer made, and all the others are AR based.
Creed, no. Grendel, yes, but you'd have to go custom. With Ruger selling the RAR in 300BO now, magazines are more available for the Mini-300. 556 cases, 308 bullets. But the venerable mini-30 has been selling for over 40 years now. They made it in 6.8spc for a short run, but you asked for 30 cal.