no where did I say a 9mm will go through more walls than a slug

Then I must have misunderstood this.

No that shit is going through multiple walls. Handguns will go probably through more.

I did watch the video. And no, it’s not basically a slug. That’s such a silly thing to say. A slug and birdshot behave very differently and would cause very different kinds of damage. Also a slug is going to go through a person at close range, birdshot won’t. That word “basically” is doing a lot of heavy lifting.

Also at 10 feet most birdshot will have a 2 inch spread. A slug isn’t having a 2 inch spread, because yes, it does have time to disburse within 10 feet.