I respectfully disagree that the caliber of a bullet is enough to classify it as such.
The M1A is based off of the M14, but I think if anybody tried to classify it as a military grade “assault weapon”, they would be disingenuous.
A number of M21 and National Match variant M14's were produced in semiauto only configuration, functionally identical to the modern M1A.
Other than the trigger group, "military grade" is not a distinction, as it should be.
The only difference between an M1A and the M14 rifle, circa 1968, that I shot Expert with, is that the M1A did not and does not have a full auto selector, while most M14 rifles could have full auto selectors installed and some did. Circa 1968 the full auto capable M14 rifles were used as squad automatic weapons. Even the full auto M14 is not deemed an “assault rifle” because it fires full power 7.62 x 51 NATO ammo, instead of the medium power ammo that’s used in genuine assault rifles.