@KARLHEIDOLPH How long are you letting the stuffed cases set before you smoke? Try about 30 hours in the refrigerator. What temp is your sausage when you start smoking them ? Try to get to 34 or 36 degrees. Lower and raising your smoke amount and duration during the smoking process. This is also a factor. Fat Content is way important to smoke penetration. Some thing to also think about is if the meat gets dehydrated it will turn the a reddish color causing a rind to form. It might look like a smoke ring this is caused by constant high heat drying the product out. If this happens add a steam pot and adjust your temps. hope this helps.
Smoking & Grilling