The Ruger Mini-30 does look like a larger caliber alternative to the Mini-14.
In this video the guy firing his Mini-30 is hitting a target out at 420 yards. Not bad!
http://www.youtube.com/watch?v=n4SVwSGPLOc
7.72x39 has very similar ballistic properties to the 30-30. Both have dropped every critter that walks or crawls in North America. I have a few .223 caliber guns but I’m not real fond of the cartridge, especially up here in AK.