What meat to fat ratio did you use? With a coarse-ground sausage it's very easy to lose moisture, especially if cooked at a high temperature. I always include pork shoulder with a decent fat content (at least 30% pork to venison or beef in most cases) and I also use a binder, but no rusk. If I want a stronger venison or beef flavour I'll add pork back fat at the same ratio, rather than shoulder. Phosphates are perfectly acceptable at the ratios stated on the packs, as is soy protein, but I almost always use milk powder instead. Around a cup to 5lb of meat is right. I forget the exact science behind it, but the proteins in the milk powder act to bind the fat particles to the meat somehow or other. Trust me though, it works greattried to keep the consistency coarse but it ended up being quite grainy.