Welcome to the forum, and to GrayBeards.
It's always interesting to read more reports on a new offering. I, among others here, have been following the 7.62x39 for awhile. The primers do seem to be the main culprit for most all misfires in this caliber Handi. I think there is still potiential to be had in this caliber Handi though, especially if you handload for it.
The whole Mil. Surplus ammo in Handi's has been debated many times, and if you do a search on it you will find several topics. NEF/H&R doesn't recommend it, but several here have shot it through theirs with mixed results.
Keep us filled in on how she shoots with different loads.
-Aaron