Here is my first pistol AR build.  

Upper - Spikes Tactical
Rail - Larue 11" Quad rail
Barrel - 11.5" Sabre
Gas System - Carbine with Larue Lo-Pro block
Brake - Noveske KX3 Piggy Brake
BCG - BCM w/ VLTOR GunFighter Mod 3
Sights - Troy flip-up Battle Sights
Optic - AimPoint CompM w/ Larue LT-129 (not in picture)
Lower - Tactical Innovations T-15
LPK - Bill Springfield complete w/ 4lb trigger job
Grip - Hogue

I have about 100 rounds through it and it functions flawlessly.  I am currently waiting for my mount from Laure.....I am hoping its in the mail today.

Thanks for letting me share.  Also in the picture is one of my new Glocks.

E.T.A. - I am getting my Form 1's ready to send in to convert this one and my partially complete 10.5" pistol into SBR's.

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Overton-Ar  Thats a nice one!  Question ? Did you have any trouble installing the KX3 and getting the pig to be were it is?

Actually I didn't assemble my upper.  I traded for it on the EE.  I only added the BCG and charging handle.  Sorry I couldn't help.