I've done a bunch of chuckies. I'm with what Ross and Johnny (rbranster & JIRodriguez) said. The trick with chuckies is depending on the meat, you may have more connective tissue in some than others. You might cook it right up to 200, then even foil and all, and when you go to shred, it's fighting you. Just slice it or put it back in (crock pot or oven is fine) to cook in moisture some more, either that day or the next, if you want it to pull easily and it won't. It is probably my favorite meat, it's not much for show-stopping presentation, but for meaty goodness and versatility, it rocks. Sammies, tacos, pasta sauce, enchiladas, chili, hash, you name it - chuckie can do it all! I do at least 2 each time, with different marinades and rubs, pull and freeze for all the above mentioned goodies. Good luck! have fun with it!