JakeTeal Hi Jake, did you use encapsulated citric acid or another cure accelerator? The reason I ask is that you pointed out that you held them overnight and if you didn’t use any type of cure accelerator then holding it overnight is what you are supposed to do, to allow the cure time to work. If you used Citric Acid and held it overnight then there is the chance that the encapsulation broke and started the acid started interacting with the meat too soon. This can cause some consistency issues, though normally it is a dry and crumbly edge, not a mush, that is possible too.
The next thing I would guess is that you have a protein extraction problem, people who read all the “what went wrong?” posts on here must be tired of reading me say that but it’s so often the issue! You want to mix, in a meat mixer until you have the proper level of protein extraction, this binds the protein, fat, water and any other additives together. For a good example of what proper protein extraction looks like go to the 1:20 mark of this video https://www.youtube.com/watch?v=wStH-RtQUY8 , the entire thing is worth watching but that will show you what your meat should look like.
Another question would be what temp was the meat at when you were processing it? It could also be that your meat was denaturing and the proteins were all breaking apart, nothing would have saved it at that point. Before grinding your meat should be as cold as possible, ice crystals just starting to form is the perfect temp. As a bonus cold meat also grinds and stuffs better, this is especially true on products that are going to get a second grind like snack sticks.
Also, we always recommend Excalibur Seasonings and not just because that is what we sell! Excalibur has an incredibly high standard of processing and a bad batch from them without the correct salt content is unbelievably rare.
With cooking, it sounds like what happened in the end is you got case hardening. Tons of things could have caused this but what happens is the outside ring of the meat cooks and hardens and it will not pass any more heat to the inside of the meat, it holds and even deflects it instead of passing it along into the center of the meat. Not sure what Traeger you were using but adding a water pan, or another way of introducing humidity, is a good idea that will speed up cook times and give you a more moist product.
Lastly, (I know, finally right?!) pellet grills are notorious for having cold spots and hot spots, so unless you were rotating them you absolutely could have had some spots that were 15-20° cooler than others! I took the Grilleye and mapped out my pellet grill so I know where to avoid or when I have a full grill where I need to rotate.
If you want to give me more of your process I can try to see what else it might have been?