FBI "HRT type" custom 11.5" Upper Receiver Group

built to order, allow 3 weeks to ship

FBI "HRT type" custom 11.5" Upper Receiver Group

An exclusive for Charlie's is the FBI HRT URG - limited edition

Custom upper build from Potomac Armory, made originally for federal law enforcement agencies.  This is an HRT style short barreled upper receiver is now available for civilians, as a limited edition.  First offered in March, 2020, the first edition will be limited to fifty (50) upper receiver groups and will be numbered.

Made with traditional FBI spec'd parts, the FBI upper is similar to that used by HRT and regional FBI SWAT teams.  Starting with a a premium law-enforcement spec premium forged 7075 M4 upper receiver and premium mil-spec bolt carrier group, the FBI upper receiver group sports a Geissele 10" Mk4 Federal rail in OD Green, with pronounced Picatinny rails at the forward end for tactical attachments. Troy folding M4 back-up iron sights are standard, and the operator can choose a Colt FBI 11.5" heavy profile barrel, or a Daniel Defense 11.5" government profile barrel, both with Troy low profile gas block, and a choice of tactical flash hiders from Surefire, BE Meyers and Knights Armament, to support a variety of suppressors.

The FBI URG from Potomac Armory is quite capable, and very versatile.  The 11.5" Colt FBI barrel performs very well with fully automatic fire, while the Daniel Defense barrel is quite capable of suppressed or unsuppressed fire.

The Aimpoint T-2 optic is optional, and mounting options offered are a Daniel Defense riser mount (SWAT model) or the Spuhr HRT version.


  • Mil Spec premium forged M4 upper receiver, black anodized 7075 aluminum
  • Geissele ACH profile black charging handle
  • nitrided MP tested bolt carrier group, full auto M16 profile
  • Choice of either a Colt 11.5" FBI heavy profile barrel of a Daniel Defense CHF 11.5" Government profile barrel, both chrome lined and black phosphated
  • Troy low profile gas block
  • Geissele Mk4 Federal 10" OD Green rail
  • Choice of BE Meyers 4-prong premium engineered flash hider; Surefire 3-Prong SOCOM, or; Knights Armament NT4 QD
  • Troy folding M4 back-up iron sights
  • Optional Aimpoint T2 red-dot optic with Daniel Defense riser mount or Spuhr HRT mount
  • multiple sling quick disconnects allow for easy attachment of a sling of your choice.

NFA Notice:  This upper receiver group, when mounted on a rifle lower receiver becomes a Short Barreled Rifle (SBR), which is tightly controlled and registred by the ATF.  You may mount this upper into a lawful AR pistol lower, and not have an SBR.  Be sure to understand the NFA laws and your local and state laws to make sure you can lawfully own this.  Also note that mere possession of a short barreled upper and an AR rifle lower in close proximity may be a violation of the NFA.