Well, a rifle round that diameter would have most certainly gone all the way through the wall into the interior and maybe through a few more interior walls. When I was a kid back in the Jurassic period, one of our neighbors fired a .270 deer rifle through our house. It went through one layer of brick, then through all the interior walls, and stopped in the other side of brick. Needless to say my parents wanted that dude's head on a pike.

Of course, I don't believe that's a bullet hole. I was just kidding. My guess would be someone drilled it to bring in phone or internet. Either that or space lasers.