Listing ID: 1735478 XM177 Style Barrels >> 5.56 NATO XM177 Style Barrel .22LR XM177 Style Barrel ; EM-4 C.A.R. At the same time, a set of baffles kept pressure up inside the gun to help ensure reliable functioning. The Brownells XM177 Flash Hider & Grenade Ring is the appropriate reproduction piece for your Retro carbine build. This flash hider mirrors the original device's exterior dimensions, as well as flash hider cuts and grenade ring. He forgot about it and recently found it in his stash of parts. The moderator was originally designed to slightly dampen the sound of the gun. New production XM177 non NFA moderators made to the exact exterior dimensions off of the Colt blueprints for the NFA version, except no taxes or transfers. To be NFA-compliant, the 11.5-inch barrel has an extended flash hider designed to replicate the original moderator and it is not select-fire. (Photos: Chris Eger/Guns.com) The XM177 Flash Hider fits 1/2-28 threads, is machined from 8620L steel and has a black oxide finish. The device included in the Troy XM177E2 is a hollow replica, yet it once again adds to the overall aesthetics. The Colt Moderator was initially designed as a flash suppressor/sound moderator to help tame the large flash and sound signatures associated with the shorter barreled designs of the AR15/M16 class of weapons, specifically, the Colt Commando/CAR-15/XM177 versions. That moderator had an ~.25" bore, and that was found to destabilize bullets, so the XM177 moderator not only added the flash suppressor to the moderator, it also punched the bore to .295". Buy XM177 Moderator: GunBroker is the largest seller of Silencers & Suppressed Firearms Class 3 Firearms, NFA & Destructive Devices All: 882058783 Colt Commando XM177 Carbine. The XM177 uses a unique flash suppressor sometimes called a flash or sound moderator for its 10-inch (250 mm) barrel. This is NOT a silencer. Barrels >> 5.56 NATO EM-4 Barrel ; 5.56 Standard 11595E EM-4 Barrel ; 6.8 Rem SPC EM-4 Barrel ; 5.45x39 EM-4 Barrel .22LR EM-4 Barrels ; Pistol Barrels >> 5.56 NATO Pistol Barrel .300 Blackout Pistol Barrel ; 7.62x39 Pistol Barrel ; 9mm Pistol Barrel Manufactured from 17-4 SS, weighing 7.2 ounces per set of linear compensator and Grenade ring, the Griffin XM Linear comp is an actual functional muzzle device, not a slug of bar stock with a hole in the middle that resembles the XM Moderator. Flash Hider: TNTE XM Flash Hider pinned and welded for NFA compliance . https://innovativeindustriesllc.com/xm177-moderator-non-functioning His options are to turn it in to the ATF or register it as a silencer. A friend of a friend has an authentic XM177 Moderator that he bought a looong time ago before they were classified as NFA items. Back in the 1960s and early 1970s, Colt was the bomb in terms of manufacturing AR-type rifles. Other Details ... 5.56 Nato 1/7 XM-177 C7 CL Pencil Style Upper.