I have not done any research as to other models, the only Tikka I have owned is the TAC A1. Not sure if it something different about them. It failed on the bolt body at the Dovetail joint. One half of the Dovetail itself broke. It has happened to several people that I know of. LRI makes a really nice Tikka replacement bolt, highly recommended them if you are ever in need of a upgrade.First time I hear about that! What kind of bolt failures they had?