Ok, here's what I know about this. I've never seen a magnum Tikka bolt, but I have the 223, 308 and 270 ones. The ejector plunger is in the same position for all of them, so that's good news. I think the largest (magnum) bolt face Tikka has is for the 300WM which should be about .530, maybe someone can measure. There has to be extra room to allow for the case to slip out at an angle so if 270WSM rim is 0.535 plan on about 0.542 to 0.545. If you have a 270WSM bolt somewhere see how wide it is. The key here is that the ejector doesn't have to be moved, cuz that's kind of a non-starter or at least a hell of a lot of work otherwise resolve.
Now for the extractor, everything is exactly the same across all three of my bolts except for the depth of the shelf that the extractor sits on. Simple, the 223 bolt has a deeper shelf than the 308 one. The extractor pivots the same. Now, the hole for the extractor spring is drilled to match the shelf height, that keeps the plunger underneath the round butt of the extractor.
When going from .384 (223) to 6.8 SPC (.422) the location of the extractor spring hole made no difference. It was close enough, there's plenty of area for the plunger to press against. So my ejector was fine, my extractor plunger and spring were fine, I just wanted to "raise the shelf" a bit on the bolt to more properly align the extractor with the rim.
There's tons of easy ways to do that and, again, the functioning of the extractor is identical, all that changes is the shelf depth. What I ended up doing is gluing a tiny piece of 0.17 thick metal to the belly of the extractor. Problem solved. Yes, not exactly a life-depends-on-it-solution but could be solved in 1000 different ways. Considering there is really zero pressure on that shim I bet it will last a lifetime.
So my hypothesis is that you can do the exact same thing starting with a magnum bolt face. This is where Tikka's simple pushfeed design is a big benefit.
As for opening up the bolt face, a local gun smith here did it with his CNC in about 25 minutes. He referenced off the firing pin hole. You could hear the cutter squealing against the hard nickel boron of the bolt, but it had no trouble. Speaking of
@LongRifles Inc. , this bolt is actually at their shop right now being Cerakoted
so maybe that can study it for science!)
Picture is below. It feeds and ejects perfectly.
-Stooxie
