I pretty much never cook turkey myself, so take all of the following with some salt, pun intended, har har. I haven't heard of someone brining turkey before grinding it, but I wonder how well that would work. I'm a big fan of brining different cuts of pork. Brining helps bring water into the meat, and additionally the denaturing of proteins by the salt lets their coils trap more water. ALSO, this water delivery system helps bring in seasonings right into the meat! There is yet another advantage, because of the greater amount of moisture now in the meat, it is easier to cook, more forgiving as it's now a lot harder to dry out the meat.
It doesn't have to be done for very long depending on the cuts, particularly smaller ones (not a whole turkey for example), I do one dissolved in cider vinegar for only 2 hours for a pork tenderloin recipe I do, and frankly it probably doesn't even need to be that long.
I also never grind meats, or buy ground meat (did buy some ground elk once in the last year), but if I got into that stuff, I would want to grind my own for sure. I saw this video at Amazon originally when picking up Cooks Illustrated Science of Good Cooking, but I'll grab it at YT to embed. There is probably more relevance with beef for all I know, but I know it's generally superior to do it yourself with any meat. If you fast forward to about 1:50, he drops a 10lb dutch oven from half a ft above. The store bought almost retains its shape exactly, whereas the home ground splatters to twice the diameter.
^ That's a PITA method I guess. Otherwise, what seasonings are you putting in there?
