
Holy tamale, Andrew, you think maybe you used too high a number charge?
Sorry, it's not funny, really -- I imagine that must have shook you up! Not to mention irritated you about the CNC machine!
Stuff like that, that's when I usually start using some choice swear words about myself.

I use a #2 or #1 (green or brown) with concrete block. I think they go up to #5 (I don't even own anything over a #3).
I always shoot into a center rib or the mortar at a rib with concrete block. And since I built the wall, I know I'm going through solid. Never had a wall penetration.
Sometimes I don't get a full bury, but then I just hammer it home the old fashioned way. I'd rather under shoot than over!
Never tried it on steel. I know it's done, but seems impossible!