@Technosavant
Combat rifle could mean whatever you want it to mean, and I would agree that it is any rifle taken into combat.
Battle rifle and Assault rifle, on the other hand, are clearly distinguished, hence the Designated Marksmen position in infantry squads. the DM's job is to engage targets between 300 and 700 meters. this distance requires a more powerful round, which is one reason the 7.62x51NATO is still in use- its too powerful for automatic fire, but fills the role of the DM- semi-auto fire for longer range positions. The 5.56x45, as in intermediate cartridge, does not have the power to engage targets at 700 meters, or even 350 meters (accuracy yes, but at that distance it will no longer penetrate body armor), but its decreased power comes with decreased recoil, meaning that sustained fully automatic fire is both possible and realistic, making the round a smart and better choice for storming, that is, assaulting, positions.
To put it simply, full power loads in semi-automatic rifles are clearly not in the assault rifle class. So what, then, are they called?
Battle rifles.
And to say that battle rifles have not been in use since the 60's is simply uninformed. There is the SR-25, the M14, the MK14, the SVD, HK 417, HK G3SG, Galatz, M39, M76 and the list goes on. Most of those use the 7.62 NATO, but a few are different- the SVD is 7.62x54R, and the M76 is 8x57IS. All of those rifles are currently in common use for the DM position for various countries.