absent any target analysis, you would want to start with disabling locomotion by going for the legs. Navigation would be next.

double aught to the leg joints could doit, depending on relative materials e.g titanium bot frame vs Antimony hardened shot.

there is a cosmetic trend for carbine length long guns and that will determine the outcome for NATO rounds.

the 5.56 is optimised for 18-20 inch barrels, the 7.62 for 20-22 inch barrels, thus providing supersonic velocities.

5.56 is really good for hydraulic cavitation of organic entities, but looses effectiveness when the transit is not clear, leaves or windage confounding.

7.62 is superior for leafy shots or nontrivial windage, as well as superior materials defeat with respect to 5.56

a taser like device cattle prod or EMP/microwave device should be in the lineup as well vs electronic hardening.