A friend I used to work with (Randy) bought a new Winchester 70, .416 Rem Mag for an upcoming Africa trip. He put a low power scope on it (I think it was a Leopold) and took it out to sight it in. He couldn't dial the scope down far enough to get the rifle to print any lower than 1 foot high at 100 yards. Besides that, it was a .416 Rem Mag, and after about 20 rounds, it had Randy so jittery he wasn't sure if it was him or the rifle that was causing the shots to go high, and Randy is a very experienced big game hunter.
Anyway, Randy asked me to take the rifle home one day after work and see what I could do with it. He said if it printed high for me, to yank the scope off it and shoot it with the open sights.
So, I took it down to the gravel pit (my "range") and put two rounds through it at a hundred yards. Randy was right - a foot high, and the SOB kicked like I couldn't believe! I then pulled the scope off, lowered the rear sight as far as it would go, and fired once more. Same thing - over a foot high at 100 yards, and by that time I was shaking. So I walked downrange, within 25 yards of the target, and because it was muddy, I just kneeled down and fired one more shot. That time the danged thing sat me down in the mud, and it still hit about 4 inches high!
Randy shipped the rifle back to Winchester. I think they determined it had a bent barrel, which they replaced, and Randy took a real nice Leopard, as well as several different species of African plane's game with it later on that year.