Considering getting one of these in 223. I have some questions. For those that have them, how many shots is it before it start losing accuracy due to heat?

I'm going to try to get this thing down to a 1/2 moa shooter (part of that will be getting MYSELF down to a 1/2 moa shooter). I suspect I won't get there with the factory stock. What is this forum's opinion of the Boyd's Pro Varmint stock?

For optics, I'm planning on using a fixed 20x SWFA scope with adjustable parallax, unless someone tells me no, they not good scopes.