It was evident that it had penetrated the glass, as the witness cardboard flew several yards behind the target.

Here's the piece of the back of the glass that was blown off.

And here's the hole in the front of the glass.

I turned it around to show you the back.

We noticed something laying in the hole.

It was a part of the slug, and we recovered the rest off of the plastic sheet.

Lessons learned:
1. This glass is tough stuff, and will stand up to a .44 Magnum, just as advertised.

2. You can "chew" through the glass by shooting in the same area several times.

3. Even though not designed to stop rifle rounds, it stopped one round of 5.56.

4. A shotgun slug that weighs 1 1/8 ounce seems to say, "I'm not stopping."

5. It's fun to shoot stuff.

Next time: Rifle rated glass.