Frustrating for you, this journey must be.
Just proceed slowly and think a lot before you get the tools out. Try to think logically about the mechanism and what is happening. Everything has a solution.
My Tikka is in an MDT Field stock. I purchased a 2nd hand Ai 10-shot poly mag from some kind chap who answered my wanted ad, and with a little guidance from the guy who sold me the stock, I had it working a dream in a couple of hours. Fast or slow, it cycles great no matter how many rounds.
You will get there.