Yes, your diagnosis is correct. Although, after 400-500 rounds the barrel may settle in a bit and start shooting more to the right from where it hits now. As far as hex wrench size...I dunno how many 32nds or 64ths it is, but I do know it was exactly the size of the wrench included in the cases of my CBOB and PM7.
Did you look to see if you got one, too?
Randall