I’m pretty sure a lot of people have heard the same line about one shot kills, to the tune that if you’re not playing a light you don’t need to worry about it. And even then it’s only if you’re not buffed.
Here’s the fact: What you heard is not true.
From the stats I’ve seen the Barnett and Mossington can both one shot you, though one of those needs to practically be up your bung first. I was a little upset at first like, “Oh I was lied to!” but whatever. That’s the game, take it or leave it. In some cases you can be one shot by the Ritchie and probably the Dragonov too.