Reese Hoffa who has thrown very close to Barnes is by his own admission quite weak by comparison to the other throwers of his caliber. I’d LOVE to see video of Johnson’s squats to see what they looked like. They’ve become an urban legend of sorts.
RE: Flo Jos lunges….I have seen a STILL photo with her with 315 on her back and I’m pretty sure she was either doing lunges or the caption said she was doing lunges. As you say though, it seems highly unlikely that they were full lunges if they were lunges at all. To lunge that much (even if it isn’t quite complete), I’d guess you need to have a squat max in excess of 450….which would be more than 3x body weight.
My favorite is when Dan told me he saw Christo Markov SINGLE LEG Squatting 300lbs. I’d also bet that Brian Wellman could have put up some big numbers, leg wise…