HK416, MR556 ARC-Fire Trigger - V2 with 416 Selectors - 2, 3, 6 Round Options

AS Design HK416, MR556 V2 ARC-Fire Trigger with 416 Selectors, 0-90-180 and 0-45-90 Position Options, and 2, 3, and 6 Round Options

AS Designs' ARC-Fire (Active Reset Clutch) trigger is an innovative take on forced reset triggers.  The trigger is reset immediately after each shot, resulting in rapid follow-up shots with one compliant round per trigger action sent down the barrel.

ASD's V2 ARC-Fire trigger improves upon the V1 with safety selector position options to better align with HK's factory markings and new, 416-style selector levers.  See included pics for selector layout.  The V2 also features a smoother detent track and larger cam surfaces for extended life.

For shooters wanting to regulate their rounds in ARC-mode, enter the CARL (Cam Activated Reset Lever).  The CARL works in conjunction with the ASD ARC-Fire trigger to extend the trigger reset after the cam-regulated rounds have been fired by the user.  Basically, the user pulls the trigger 2, 3 or 6 times (depending on the cam) and once the cam has counted those rounds, the trigger requires a full release to reset before regulating the user-fired rounds again. Additional cams can be purchased to change the round count.  Simply remove the CARL, replace the interchangeable cam to the desired round count, and reinstall.   

Standard AS Designs AR-15 ARC-Fire kits are not compatible with the HK416 and MR556 platform.  This kit provides the necessary components to function in those HK rifles.

NOTE:

• Only the included selector levers and ASD's mil-spec levers are compatible with the ARC-Fire kit as the selector lever is part of the ARC mechanism.
• Does not require a full-auto BCG but a FA BCG will keep the trip lever from flipping backwards in the receiver and disengaging.  
• IF your rifle has a semi-auto BCG: Actuating the charging handle with the muzzle pointed upwards will disengage the trip lever.  To re-engage the trip lever, simply actuate the charging handle again with the muzzle pointed towards the ground to reposition the trip lever into the correct orientation.  

Compatible With:

• HK416 A5 (1.8mm gas vent screw recommended)
• HK MR556 A4 (1.8mm gas vent screw recommended)
• HK MR556 A1 (will require an adjustable gas block to cycle)
• HK416 A1, A3 (will require an adjustable gas block to cycle)

Restricted States:

• CA, CT, DE, FL, HI, IL, MA, MD, MN, NJ, NV, NY, OR, RI, DC
• No US Territories or international orders.

Depending on your configuration and ammo selection, you may need to increase or decrease the gas vent screw size.  MR556 A4 rifles and pistols are equipped with a 1.3mm gas vent screw from factory.  A 1.8mm gas vent screw was optimal for our MR556 A4 11" and 16" barrel rifles using standard M195 ball 55gr 5.56 ammo.  User experience will vary, therefore, it may take some trial and error to identify the perfect size gas vent screw for your particular configuration and ammunition.  Most configurations will cycle well with a gas vent screw in the 1.6mm-2.0mm range.

Ejection patterns should be approximately 3-4 o'clock. If you observe your casings ejecting closer to 1 o'clock (over-gassed), go UP in vent screw size to CLOSE gas block. If ejecting closer to 5 o'clock (under-gassed), go DOWN in vent screw size to OPEN gas block.