Tell me why I think this clip is funny.

I originally posted this at Facebook but they blocked it from everyone's view because it might be copyrighted content.

Fuck them. Here's my FB post:

"This clip is from "Pure Luck" with Danny Glover and Martin Short. It's a comedy anyway, but I'm sure the director didn't intend for me to get such a laugh out of what I saw in this scene.
See if you can tell why I thought it was funny.

Just a tip. People familiar with firearms will get it."