You're right, that second shot, the double tap, is important with a handgun, especially the lighter calibres like 9mm. Being able to back up quickly and accurately is the key.

I'm not so good with a shotgun, not bad, just better in long guns and handguns. I'd still not advise standing in front of me if I had a shotgun and the intent to use it though. I can hit stuff.

I hope you're well and you have a good weekend ahead.