I used a 25% (18.75 lbs venison and 6.25 lbs fat) fat content in vension smoked sausage. Around 80 degrees the pork fat started to melt. I usually use bacon ends and pieces and it does not do this. The fat and meat were single ground in a 4.5 mm (5/16") plate. The fat cut into cubes and frozen before grinding and I used ice water for mixing in the spices. The mixture rested overnight in a 33 degree cooler and was cased the next morning in 32mm to 36mm natural hog casings. The link sausage was smoked to 145 degrees and the temp never went over 160. It stayed arount 150 degrees the majority of the time. When done, the liquid fat had settled in the bottom of the links and the tops were dry as all the fat had gone to the bottom.
Also, would it be better to use whole pork shoulder instead of bacon ends and pieces or straight pork fat. I can't get enough back fat which was recommended.