New to 6.5 but ready to build upper with questions.

[LRRPF52]

For the Gas tube, Id go to Primary Arms. I use JP adjustable gas blocks in all my ARs. For the bolt, buy it from the same place as the barrel, and have them check head-space before it leaves there hands. The mags you can get from eBay for 15 bucks apiece. They work fine. The gas block will make a lot of difference. Grendel barrels run an over-size gas port(.125) to accommodate lower chamber pressures of the 6.5 round. End result is considerable over gas. Like the bolt carrier slams into the back of the upper kind of over-gas.

Addressed in the other thread as well.

This is incorrect. I don't know why anybody would intentionally cut a .125" gas port in 6.5 Grendel.

Chamber pressure is much lower than 5.56 NATO, but case capacity is much higher, and projectile weights are much higher as well, so you have very similar port pressures, and hence, port diameters.