I haven't personally seen this type of damage with Tikka's straight-feed mags but have seen it on my old Ruger M77.  That damage looks severe an will definitely affect performance.

I would make some dummy rounds and check the feeding with the stock removed.  You may see that the mag is moving during cycling or does not seat properly in the first place.  If the mag function looks ok, I would next try changing bullet seating depth.  If damage still occurs, then I would consider a trip to the gunsmith, or changing to a bullet style without exposed lead i.e. Polymer tip or jacketed hollow point.

Good luck!

Light gun + big cartridge = bunged up tips. My 300 wsm does the same.

I've been single feeding with a single shot follower- works quite well for me for now. 

We should be able to start machining our long action bottom metal & metal T3 magazines pretty soon (this is definitely a big reason why we want to make them). We hope to have it worked out by summer. It might be as simple as running a heavier spring in our metal T3 mags, or maybe machining stops into the sides of the mag well to catch the brass shoulder before the tip can contact the front of the mag.

Hi a guy I was teaching to shoot last week kept getting the a same damage it was an old Parker hale .308 he was being too forcefull with the bolt , got him to slow down with the bolt , no more damaged rounds