Might try out a new mix for burger this year. For the past few years, I've used about a 3 to 1 mix of either 3 parts deer, elk, or moose to 1 part 80/20 (fatty regular hamburger) to the new burger.
I first medium grind the lean, tougher trimmed cuts of the animal, then mix the regular burger and grind that again. Vacuum freezer wrap and it keeps well.
Heard of others using a pork roast or just using cow fat from a butcher to add.
Any ideas? comments?