HK416, MR556 ARC-Fire Geissele Trigger - 3-Position - Ambi Controls

HK416, MR556 A4 3-Position ARC-Fire Geissele Trigger with Ambidextrous Controls

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. Couple that with Geissele's trigger wizardry and you get the quickest follow up shots in town with the cleanest trigger break on the market.

This 3-postition trigger with ambi selector levers is a direct fit in MR556 and HK416 firearms but the selector levers do not align with the factory pictogram.  See included pics for selector layout.

NOTE:

• Only the included selector 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, VA, WA, DC
• No US Territories or international orders.

Tuning Your Rifle To Cycle Reliably:

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.