Brent,
My brother worked in an Italian salumeria for over a decade and he’s the family expert in squishing meat into animal entrails. His take is that there isn’t a script to making sausage, it’s a very hands-on process that requires a lot of practice and quick reaction. He said the meat mixture absolutely has to be cold enough so that the fat component of the meat is like a soft playdoh texture. If the meat heats up at all where the fats start to lose their solidity, then it makes the process impossible. They even had one of their meat grinders in their walk in fridge so that everything stayed nice and cold. The casings need to be soaked so that they are pliable and easily stuffed. He said they would also lube up the casings with a little oil to help the ground up meat slide in easily from the insertion tube. Grinder speed is key as you have to push the meat in at a consistent rate but not so fast that you can’t tie off the sausage. So it’s best to load the casing onto the tube and then make sure that there’s only enough casing extended to make a sausage link at a time. You basically want the grinder to create the “meat pressure” and do all the work to “inflate” the casing and then tie/twist off quickly before the casing pops.
I’ve seen him do it first hand and it really is artistry at work. The “old man” (Carmine who owned the store his entire life was like 85 years old at the time) could make an entire length of sausages in minutes and keep the process going like a machine....all the while cursing at all his employees in Italian to go do something useful...
Give it a try you would be amazed how fast it cooks everything and the smell is great. We have ours in the Flamingo Lounge so it does not smell up the house 
