Who has the Brownell's 18" 6.5 Grendel barrel? What buffer, spring, gasblock setup?

[m796rider]

I have this barrel, but cut back to 17". It throws brass to my 2 o'clock but the bolt does lock back on an empty mag. I'm going to try one of my Tubbs flat wire action springs to slow down the BCG a tad. All my bolt carriers are M16, by the way.