I am looking for some information about the barrels and stripped uppers. I know the lower can be a standard AR but the upper, barrel, bolt and Mag are special. I have looked at Alex armes and a few others but I was looking for the best deal.
I think these are about the only mags in town. You can buy them from Cproducts or AA.
I've read a standard upper will work, but the ejection port may have to be enlarged just a little.
IMHO the only bolt to go with for the Grendel is one from AA, seems to be a bit of a disagrement over the way bolts for this cartridge should be made.
The link that Cold gave you will have all the info you need about the Grendel and available suppliers.
BTW, I really like my 6.5 Hunter model.
you can get a previously owned AA upper
Good deals on the site
Go with an AA upper/BCG/bbl and you will be pleased.
If not go with a Satern chrome lined bbl and lap it.
BTW the hunter upper makes a nice place to start for a free floated bbl setup.
I like the bbl to be full diameter to the muzzle.
Check out Satern barrels. They have a banner ad at 65Grendel.com