Time to shoot my case:
Trying to decide where to put the holes.
I had originally planned on using the .40SW pictured, but at the last minute, my father, who is a ballistics expert, warned me that the .40SW is too large and too slow to make a good looking hole. After doing some test shots on some other metal I saw that he was right. The .40 SW tore it to pieces.
So plan B: the classic .223. And it worked like a charm.
Unfortunately I do not have video of the event, but the results are here. I did not want to risk shooting from a distance and missing the marks so I shot at very close range. The escaping gases at the muzzle bent the panel out of shape a bit, but I was able to bend it back no problem. Also, the blasts took off chips of paint, but that just adds to the effect.