I'm pretty partial to the M-14 platform.... Biased some would say....
In my experience, a base M-305 and $500 in parts is 600y capable. I have seen a stock rifle with an upgraded rear sight make consistent hits on a 18" plate at 600y. I have built 3 rifles, for myself, using Chinese barrels that are 600y capable. I know another fella who has made hits at 1000y with a scoped Chinese M-14.
You give me $1500 and I can guarantee 3 MOA with factory ammo.
You give me $2500, and I will guarantee 2 MOA out to 300 with factory ammo.
You give me $6000 and I'll build a rifle that is 1000y capable and 1.5 MOA.
It has also been my experience, that a Springfield will require the same tunning and tweaking the Chinese rifles do..... For a much higher purchase price.
It will likely be more expensive to tune a M-14 into a long range gong ringer than to just buy a (insert brand here) bolt gun; but that really isn't the point is it?