The Ruger 10/22 again
I own a fair number of rifles, shotguns, and handguns.
IN MY EXPERIENCE, not my opinion on firearms I didn't own or didn't own very long, the most overrated is one of the few firearms I ever sold - a Ruger 10/22 I bought somewhere around 1974.
It took me a few years to sour on it - years in which I shot God knows how many gophers with it. It was never a tack driver, in fact grouping ability was pretty mediocre with any ammunition I felt was reasonably priced i.e. nothing like Eley or Lapua. But most gophers were shot at around 25 yards or less, standing up, and most were shot dead. It never jammed, although I now read others saying they jam like crazy: mine and my brothers' didn't.
But eventually I realized that the more and more I tried longer shots (as the easy gophers at closer range got thinned out, perhaps), the poor grouping ability and the lousy trigger pull were a problem I couldn't get around. Back then, all the current Kidd and Volquartson stuff didn't exist. So - in my mind - it became overrated as it was hyped as being about as fine a .22 as a blue collar guy could buy. A small game .22 should have at least a decent trigger and be able to group at least as good as my Cooey Model 39, which it didn't.
So I sold it and bought a Remington 541. My brothers at some point came to the same conclusion and dumped their 10/22s for the same reason: great bullet hoses for slaughtering gophers and tin cans at reasonably close range, but didn't have the trigger and grouping ability to go after gophers, starlings, and magpies further out there.
Both of them now own 10/22s again, BTW, with replacement barrels and all kinds of other drop in stuff from Kidd and others. Their new 10/22s with the replacement parts are now tackdrivers with great triggers - but they aren't the 10/22 rifles that they brought home new in the box a couple of years ago.
Nothing wrong with a 10/22 from my personal experience - just that as a stock rifle, they don't have the trigger pull and grouping ability to match the overrated reputation. Maybe some of the new ones, I don't know, but not the ones of the 70's, 80's, etc.
Other rifles can go the other way. I have a Sako Finnbear I bought around 1974. Beautiful rifle, shoots well, classic looks, great workmanship and finish, etc. Would never consider selling it. Meanwhile, looking at the latest Sako big game rifles, they may or may not be just as good or even better as far as performance goes. But the lines and styling of the new ones remind of Browning's descent into marketing gaudy shotguns with cosmetics and looks that make you think they hired a Davie Street drag queen to do the design work. I think of Sako hunting rifles as classics in lines and looks - the new ones are overrated if the claim is made they meet that standard.
They're running with the reputation that the classic Sako rifles earned, and they don't live up to it.
The hands down worst rifle I've ever owned was a Ruger M77 heavy barreled 220 Swift I bought new in the box somewhere around 1978 or so. Had a few tiny problems: you couldn't seat bullets out far enough to even get close to the lands, and when I drove a slug down the barrel, it went into free fall for about two inches around the middle of the barrel. Best group that thing ever shot, no matter what bullet and what powder, was about 2 MOA. When I brought it in as warranty defective, Ruger essentially told me it shot good enough and to go pound sand. I sold it to a guy who was drooling for a Swift, and who still wanted it despite my telling him what was wrong with it. Maybe I looked too young to be as smart as he was, but I was happy to take his money.
Said I would never buy another Ruger after that, and never have. Never will. But I wouldn't say that, based on my experiences, the Ruger M77 line of rifles are overrated.