We've had a few kunes go away, and deadweights of 48 and 50 sound not bad at all, especially if they're not fat that's a reasonable return.
I find it much harder to send the pigs away, have a bit of a lump every time we have done, although I have home slaughtered lambs we've fed on the bottle and been fine with that!
Our last were 50, 55 and 60, and we got 70kg of sausages back (hence the other post comparing dead weights to sausage return, as we're not convinced the butcher is being totally honest with us)