Who's got a Grendel SBR

[LRRPF52]

I would look more at getting the dwell time you need for reliability, so when I look at SBR's, I prefer the 11.5" or 12" with 5.56 guns. Since the Grendel uses a larger gas port diameter on the Mid-length 16" pipes, I'm thinking more dwell time is better, regardless of port diameter, since shorter dwell time lengths need high-impulse via large gas ports to run reliably. I also like rifle-length handguards with floated suppressors underneath.

Is the 16" you have coming already drilled at mid-length for the Grendel? That could be a problem for SBR lengths...