The 6.5 Grendel
The primary advantages of the 6.5 Grendel are that it uses the smaller and cheaper AR-15 platform over the Ar-10/AR-308
as well as going head to head with the 308 in performance with only half the recoil.
Here is a great site with more info >LINK<
More info on the creation of the Grendel here >LINK<
The AR-15 will almost always come out lighter as well and if you are walking or sitting in a stand the weight may or may not matter.. it depends.
The main reason this smaller cartridge can compete with the larger ones is it uses the most efficient bullet that are 3-4 time more aerodynamic and flatter shooting.
As to cost the bells and whistles don't make your aim any better.. but an amazing gun can be built for around 700-900 without a scope.
Here are some links
Black Hole Weaponry 6.5 page
QMS _ Trigger upgrade from mil spec
Bolt to match the BHW barrel
lower parts kit
one of the best brakes on the market
That just leaves the stock and some misc parts, and the stock depends on the buffer kit either a carbine or rifle. see here >LINK<
Some of the random Grendel builds online for inspiration. Photos belong to their respective owners.