I took a bit of time out today for a range trip, mostly to get my Shield's round count up closer to a thousand, but I brought my MP9FS as well. It was rainy, and there was a puddle in the grass next to the shade structure. So I thought, hey why not?

So I emptied it, removed the mag, locked the slide back, and dropped it in the puddle. Then as it marinated, I put five rounds into the mag, then fished it out.

I simply slid the mag in and slingshotted the slide as usual, and it didn't go into battery. Muck, grit, or blades of grass were interfering with the slide movement. With the ammo out, I dragged a finger into the ejection port and pushed away what I could reach. Bang, but the next round didn't feed. I cleaned it a little better, and got two rounds to feed, one ejected as the next was being fed and jammed it. One round had dropped in the puddle when I was clearing it, but it fired just fine once I'd wiped it off with my shirt tail.

Conclusion... those internet torture tests don't guarantee results for YOUR gun. Do they clean them behind the scene? Who knows.

But I'd recommend you try a test like this with your favorite gun, just to see what the real world has in store for you.