Ive killed plenty of critters with bergers. Also, been a part of quite a few of other's kills. I have experienced a couple bergers, penciling thru and not expanding at all. It's been very rare, but it has happened to us. We found a bullet one year in the offside hide that was still fully intact. This was more than 10 years ago and I dont recall all the specifics of yardage or impact velocity. Apart from those rare instances, the amount of internal damage on most of the kills was nothing short of fantastic.
I still shoot them in quite a few of my guns and love their accuracy. This year I plan on letting my 6.5 BB eat with the 130 vldh.