I always use beef fat for burger. IMO pork fat is for sausage. I like about 1/3 beef fat to 2/3 venison on the 3/16" grinder plate. If you make it that fat, you can make hamburgers with it and they will be good. If you are running short on fat, you can get by with half that amountand use the burger for spagetti, tacos, and chili.
Close enough to what I do.
8lbs venison and 2 lbs beef suet all the way up to 10 lbs venison and 2lbs.fat. more or less depending on your taste. For meatloaf and meatballs I add beef and pork fat instead of all beef.