I'd add 7.62x39mm to the "approved" rifle list.

FIRST CHOICE = 22LR
SECOND CHOICE = 5.56x45mm (223Rem) or 7.62x51mm (308Win)
THIRD CHOICE = 7.62x39mm (M43 Russian)

Must have a 22 rifle to compliment the 22 handgun.

If you're wanting a semi-auto centerfire rifle:

BCM or Colt AR15
DSA SA58 (FAL)
Arsenal SLR-106, SLR-106FR, SGL-21 (AKM)

All the above are top quality and parts availability is abundant.

For the esoteric:

FN SCAR-H
IMI Galil (5.56 NOT 7.62)

Any of the above will outlast you, and will provide generational service.

ETA....for rimfire rifles I prefer:

Ruger 10/22 (semi-auto)
CZ 452 (bolt action)