I just saw this message from almost 2 years ago, I don't think I ever replied to it, come to think of it I'm sure I haven't as didn't know this area of the LRH website was even here.
Did you ever build your rifle?
I used a Manners T4 90% carbon fiber shell stock (which is similar to an A5) for mine, used an ABS/Rock M24 contour 30" 1-9.4" twist barrel.
Likes the 300gr Bergers with Retumbo, puts 3 into .5 moa out to 1195 yds.