...Not sure any advantage to it...
THESE days, that is a BIG advantage! I sold my brass, dies and mould with the 527 Youth Carbine last summer, but while I was messing with it, I was constantly watching for ANY 7.62x39 BRASS. It was not nearly as easy to find as 30/30, which was one of MY reasons for settling on the 30/30.
GREAT rifle for cast and GREAT little rifle to do cast in. The Mini-Mausers are just ass cool, but have the advantage of the integral, staggered box magazine. Neither is chambered for 30/30, obviously.
I will keep an eye out for brass for you. My only real social contact is with my students and I usually have several who are shooters, but for some reason, all but a couple this semester just WANT to get into shooting, but are not yet. I hope that's not a trend.