I finally built an AR after tinkering on my other rifles and other people's ARs for several years. I have always loved PDW's so I built a 7 1/2" 5.56 pistol. Below is the parts list. Anderson upper and lower receivers Classic Arm's Premium 7 1/2" 1/7 twist barrel with generic A2 flash hider. Seekin's Precision adjustable gas block Classic Arm's Premium BCG UTG Pro Super Slim Keymod 7" rail with QD sling adapter UTG Pro Super Slim handstop/barricade rest UTG Keymod rail covers BCM Keymod 45 deg. Offset mount Streamlight TLR1HP light with Surefire green filter Holosun HE-510GR-Elite red dot sight GG&G BUIS set with Blitzkrieg Components Tritium Chevron front sight and Meprolight rear aperture Raptor Ambi charging handle Strike Industries forward assist Engraved dust cover from CustomARDustCover.com SB PDW brace kit Magpul MOE plus grip Geissele G2S trigger Geissele Maritime bolt catch Troy ambi mag release with Odin Works extended mag release paddle KNS pin set Battle Arm’s ambi safety Tactical Link single point sling or Magpul MS1 depending on mood. Strike Industries +5 EMP mag plate At first it was way overgassed, so I installed the Seekin's gas block and that fixed that. So far after >200 rounds there have been no malfs at all. It will shoot into an inch at 65 yards with Frontier 5.56, 62 gr. SP ammo.