Freeze all your grinder parts for at least 20 minutes before you begin (grinding plates, blades, tray and the bowl that will receive the ground meat). Prepare your hog casings by soaking in some cold water to remove the salt. *see package instructions. I replaced the water three times. Be careful not to pour your hog casings out with the salty water, they are very slippery.
Make sure your meat is very cold. You can freeze this for about 20 minutes before starting as well. Cut chilled meat into large cubes (about 1-2 inches/2.5-5cm) making sure they will fit through the feeding tube on the meat grinder.
Grind both venison and pork fat together using the course grind plate. You may want to chill it again for 20 minutes, then grind again on finer grind plate. If needed, chill again for 20-30 minutes before next step.
Mix the prepared meat with all of the remaining ingredients except the hog casings. I use my hands just like when I make meatloaf. And yes, you may need to chill it again. Everything needs to be kept cold. Not frozen, but cold.
Stuffing the Casings
Take the blade out of the grinder, and assemble the medium size funnel/tube. Load one casing onto this like a pair of socks with a big hole at the end, do not tie it off at this point. Start feeding the meat mixture until you see it at the opening of the tube. Now tie it off with twine, or with itself and continue feeding. I do this because if you tie it off before you start to feed, it creates a big air bubble at the end. Continue stuffing, being careful not to stuff too tightly or it will burst (see video where it bursts above), until you reach the last couple inches of casing then tie it off. Load another casing onto the stuffing funnel and repeat process.
Once done stuffing all the casings, pinch sausage at around 4 inches from one end to create a separation point and twist a few times, repeat this all the way to the end, twisting in opposite directions for each twist.
Pierce any air pockets with a sterile needle, sausage pricker or a toothpick. Hang the bangers, or lay on a tray overnight in the refrigerator to let the flavors develop.
How to cook Banger Sausages:
Heat a tablespoon or two of oil on medium/high in a large skillet and cook sausages for 5-8 minutes per side. Once browned, put enough water to cover the bottom of the pan, and put the lid on. The steam will continue to cook them and keep the moisture in the bangers as well as help prevent them from burning. Or roast sausages at 400°F/205°C for 10 minutes each side or until done. They are done when internal temperature is 160°F/72°C.
If you over stuff and a casing breaks, just cut the casing at that point, squeeze an inch or two of the meat out and tie it off. Start again. I do not recommend a plastic meat grinder for large quantities.