This Stevens bolt action 20 gauge is the worst gun I've bought. I paid $85 for it thinking it was at least a functioning gun, but the stock was cracked around the single retention lug (a bolt that goes vertically through the stock and screws into the action). This caused the action to jam itself backwards in the stock when it was fired and you had to smack it forward to cycle the bolt. I got tired of this and drilled a horizontal hole through the stock to insert a bolt right behind that stock attachment lug to prevent it from slamming back in the stock, and the lug sheared off 3 shots in. I slapped some hose clamps on it to hold the action down, took it out maybe three more times, and I haven't shot it since 2015.

A very close second would be a $1300 S&W 986 PC that arrived in an unfinished condition and would barely work. I took it apart, fitted all the parts right, and it's become a very good revolver, but that's the worst new gun I've ever bought.
>>63910743
What the fuck, those things were everywhere for a dollar a piece 15 years ago. I guess they dried up like everything else.