Hmmm. I never noticed that! I've never tried to turn the rear baffle (part #28), but it turns freely around the bolt.
Live and learn.
If your Model 111 is like mine, it's going to like a number of loads, powders and bullets. My current load is a nearly full charge of Reloder 19 and a 150 Nosler BT. It shoots into 3/4 of an inch. I haven't chrony'd it yet, but intend to sometime this week. It also like 165 GameKings and IMR 895, along with Hornady 155 A-Max and Reloder 22. There's lots to like about that rifle.