I'm on the list and will stay on the list. Sadly my addictions to NFA are bigger than my pockets allow. There's gotta be another way.
Even if I got my FFL and SOT I'd still buy from you bro cause you're the best.
I think the M is 5" and the Grunt is 6.25" that Exo looks cool but would prolly just be covered with the rail in your build.
Shout Out
@DarthVader is top shelf honest and trustworthy and has tons of knowledge in building rifles. I trust his advice.
I have the Spectre II and love it. Great on pistols bolts or semiautos. I've shot the ARC22 side by side with the Spectre and really can't tell the difference between the 2.