Yes. In sociology (and a great many areas of soft science and the humanities) the majority view is by definition the right view. So the group view and the right view will tend to coincide. It's a subtle form of confirmation bias.
That doesn't apply to physics.
Several different issues here, but the group polling dynamic actually works far beyond confirmation bias. Certainly if you ask folks what the best flavor of ice cream is and 87% say chocolate, then chocolate IS the best flavor because they all said so.
However, if you ask a large enough group of the same people some question of hard-science or history fact (Q: Which year did Vasco DeGama first land in India?) and give them a set of choices (A: 1450, 1498, 1515, or 1537?) the group does tend to pick the right answer more often than not. That's rather the opposite of confirmation bias.
It doesn't even apply to the stock market or home prices. Did the group here predict two years ago that bulk pack .22lr would be a rare and precious substance today? No.
This is a bit of a red herring. The group has to be given all the relevant information in play, and this of course can't predict outlying oddities and unforeseen events.
If you'd polled gun owners a totally blind question like, "How much will a brick of .22 LR ammo cost in March of 2013?" They'd have totally blown the answer. If you'd said, "If we have a highly publicized mass shooting of children during a Democrat presidency and in an intensely polarized political climate, what will the price of a brick of .22 LR ammo be four months later?" They'd be quite likely to guess a price point not very far off from reality.
Bringing this back to the realm of the discussion we're having here, when there are pretty much two choices (Option A: JHP, or Option B: mixed ammo, mostly FMJ ball) and the debate over the question had largely been answered decades back, with NO relevant new data arising in that time to lend further support to the value of "Option B" -- the group really doesn't stand a chance of getting the answer wrong. Calling their answer "groupthink" makes it sound like the answer is questionable or worse, which is a way of casting doubt on the answer's validity without having to provide a legitimate basis for that doubt.
"
Battery acid is poisonous! Do not drink it!" ---> Pshaw! That's just groupthink! Be a free thinker! They don't want you to know the TRUTH!