I've been told they can swallow bass up to about 2 lbs. Haven't seen it but there is a lot of stretch to that throat. I know for a fact they will impale any size bass. If it moves their natural instinct is to impale it. I have seen scars and fresh wounds on some of my larger bass.
I WILL be putting up an electric fence to keep the SOBs off my warmwater pond. Not only to they lower the value of my bass by mauling them they also add parasites that lower their value too.