1. Always use a meat thermometer on large pieces. Take out of the oven and rest the meat when it reaches 70 oC. Perfect every time.
For a shoulder of venison add garlic, resemary, salt/pepper, olive oil. Wraop in 5 layers of tin foil and cook on the BBQ for a good tme . You end up with a tender well cooked piece of meat as the steam/moisture stays in the meat and helps speed the cooking up.