Thread: Tikka M55 action build

I have owned 3 M55's and still have one, opening out the bolt size to .308 generic should not be a problem, however if you want to change calibers you will need a different magazine, as far as I recall they are available ex the UK but are not necessarily easy to procure, and not cheap. Before you embark on any serious project take your bits to a reputable gunsmith and have him carry out a technical assessment. I bought one a couple of years from a forum member to fit a 1:8 twist barrel to, I test fired it and found that the grouping was around 1.5" at 100 yds which is less than spectacular for these guns. The gunsmith found that someone had modified the bolt locking lugs by removing metal from their aft end to effectively taper them, probably in some misguided effort to make the action smoother, problem is that it was ineffectively locking on two points rather than on two large flat faces and to repair it was not an option. The rest of the gun was in very good condition. This modification work was not carried out by the forum member that I purchased the rifle from and he was unaware of it, he took it back. While it's highly unlikely that you will have the same issue, these guns are generally about 40 years old and have seen a lot of life go by.

Funny thing is that I re-read your post and see that the global effect of the Coronavirus has seemingly affected my normally acute focus, just ignore all what I said about the bolt face and mag as they are .308 already.