Remember Mike the rifle is brand new and it is a stainless barrel.. some rifles take time to break in and some do not.

The first thing I would do is get rid of the thumbhole stock in your situation. I would rather have a conventional then one I had to hold as you described. It kind of defeats the reason for the stock. But if your happy with it, then what does it matter.

As for the primer, I am sure with practice you will get it all worked out. Use a shot off one and practice with that some evening, capping and decapping until it becomes second nature.

Last thing I would do is if the rifle suddenly acted like that, check the scope and mounts. Sometimes new mounted scopes will come loose.

Actually a lot of rifles settle down after the first few outings.. keep us posted. It sounds like you have a good shooting rifle there.