Tikka M55/ Ithica LSA 55 Barrel shank

[JoeDirt961]

I'm in the process of barreling a tikka M55 action and after all of my googling I have found nothing on the breech face specs. Can anyone help out with a drawing or even a picture of the Breech on either a tikka M55 or Ithica LSA 55.
Much appreciated