Consider that the M193 55 grain from a 20" barreled M16A1 travels at 3300 FPS, and is still faster at 200 yards than the 2500-2600 fps needed to reliably yaw and fragment (the main mechanism for grievous wounding). The M855 from a 14.5 inch barrel barely breaks 2750 FPS at the muzzle and drops below the 2500-2600 FPS at 75 yards. I have seen hits from M193 in my LEO career, and I'll just say they are NASTY! The early 1/14 twist barrels were only marginally stable (like 5.45x39 7N6), and they really made bad wounds.
At close range, the M193 even surpasses the MK262 MOD1 77 grainers. past 100 yards, the MK262 surpasses, but under 100 yards, it is hard to beat M193. It was this reminiscing about what I have seen, and re-defining how I intend to use my KISS Carbine that made me decide to sell off my MK262 and M855 ammo to fund the project.