It does not matter if you go brake, FH or thread protector. On the Grendel forum you see completed Grendel's with everything. I think most do the mb since that's what's required due to state law. The best muzzle break imo for the Grendel is the one made by precision firearms. The worst flash hider imo is the AAC 51t, because it makes a ping noise after each shot.
I've shot the Grendel and the .264 LBC quite a bit. I have 4 in different configurations. I have tried many different brakes and compensators. What has worked best for me has been the Fortis .308 brake. It's easy on my ears in hunting situations where one maybe two shots are necessary and it truly reduces recoil from what little recoil the Grendel already has. With my heavy AR's they barely move and it is great for when I'm shooting Chucks at 20x or 25x power on my optics.
I also run the Fortis "Red" .223/5.56 brake on my 6x6.8 SPC. With no need to have brakes bore dimention opened. It has just enough clearance for the 6mm diameter bullet.
Last edited by SMACK; 11/20/15.
All the best things in life, live on the other side off fear.
The true eye sees not the despair of its victims, only the elegance of equilibrium. It's a demonstration of superior judgment.