HK416, MR556 ARC-Fire with Geissele Trigger - V2 with 416 Selectors - Ambi Controls

AS Design HK416 and MR556 V2 ARC-Fire Trigger with Geissele*** Trigger, 416 Selectors, and 0-90-180, 0-45-90, and 0-45-180 Position Options

AS Designs’ ARC-Fire (Active Reset Clutch) trigger is an innovative take on forced reset trigger technology. The trigger is reset immediately after each shot, allowing for extremely fast follow-up shots while maintaining one compliant round per trigger action.

This V2 ARC-Fire kit pairs AS Designs’ updated ARC-Fire system with a modified Geissele trigger for a cleaner break, smoother feel, and fast follow-up shots. The V2 improves on the original ARC-Fire design with updated selector position options that better align with HK factory markings, new 416-style selector levers, a smoother detent track, and larger cam surfaces for extended service life.

This kit is available with 0-90-180, 0-45-90, and 0-45-180 selector position options. Standard AS Designs AR-15 ARC-Fire kits are not compatible with the HK416 and MR556 platform. This kit includes the necessary components to function properly in compatible HK rifles.

***References to "Geissele" are for identification purposes only and do not imply endorsement.  Modification of Geissele products (as conducted) voids Geissele's warranty.  Geissele accepts no liability with respect to modified triggers.  Trademarked names and patents remain the exclusive property of Geissele Automatics.

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 ***NOT compatible with 180 degree HK style levers (1.8mm gas vent screw recommended)
• HK MR556 A4 (1.8mm gas vent screw recommended)
• HK MR556 A1 ***NOT compatible with 180 degree HK style levers (will require an adjustable gas block to cycle)
• HK416 A1, A3 (will require an adjustable gas block to cycle)

***The HK416 style lever is blocked from fully rotating into the final 180 degree ARC position by the receiver detent.  Refer to the last selector lever orientation picture above.  Compatible mil-spec. levers will be offered end of May or early June.

Restricted States:

• CA, CT, DE, FL, HI, IL, MA, MD, MN, NJ, NV, NY, OR, RI, DC, WA
• 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.