While that may be true, it is not all of it when it comes to many of the matches in the area. Consistent trigger pull, cheek weld, breathing, positional shooting and racing against the clock are all needed skills that can be practiced at any distance.
I have two rifles in McRee stocks and both are folders. As LeadPumper said it makes it much easier when cleaning. On my .06 if I didn't have a folder I would have to take off the cheek rest pack to get the bolt out.
I have 2 of the McRee Chassis for my Rem 700's. The McRee chassis is a complete bolt in and comes with one mag. By the picture on Brownell's it looks like you still need to add the stock for the rifle with the Tac21.