Hi Palbirds
It depends on many things like, are you using filler, do you use your sprew (leftovers) effectively? I get on average about 150 to 180 4 inch worms salted. To a kg the difference comes in if the tails are a different colour or not. I use injection mold and don't hand pour these, Hope that helps. Send me a PM if you need any more info and I can send you thye basics, also if you type in the search you will find a lot of useful information.
Cheers
Nutt