We have had a sorta curvy path on getting our MTR together, but it is getting there slowly. I'm for now just planning to play around and accessorize the stock rifle a little and will look at optimization and/or parts replacement later, if at all.
We broke the rifle in my shooting bench and prone on sandbags with an Vortex Diamondback scope. I got the feeling right away that it was a shooter because the gun wasn't optimized and it was shooting under an MOA at 50-100 yards in lousy conditions, like winds that moved the shooter around a bunch.
About a month ago, my son bought a Vortex 5-25 Strike Eagle and I got a 30MOA rail and rings. Then a couple of weeks ago, I used Lash's approach to mount a rail, then put an Atlas bipod on it. Even with variable winds, it mostly shot groups at 50 yards in the 0.5 to 0.7 MOA range and had a few groups below 0.5 MOA. Best was 0.24. One group had 4 shots into 0.13, then a flier, so I think that's a range to strive for.
I'm normally prone to be a trigger snob, but I like the stock trigger and I've left it untouched so far. We've had good performance from Norma Tac-22 and excellent performance from Lapua Super Long Range. A few CCI cartridges have been good, but none stellar.
I do realize that the group sizes I mentioned above are not hot shit for competitive shooters. Back when I had decent vision, I was competitive enough to know good. Now I'm just a blind old fucker that can't shoot for shit.