I have no experience with that particular rifle but the symptoms point at barrel bedding. At least they do for me.
Is there any way to free float that barrel? That would be my first solution.
Hope this helps.
By the way, how does the last few inches of a barrel get shot out. That, I don't understand and I've never heard of it.
I may be the slowest guy on the mountain . . . . but . . . . I'm on the mountain!