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4 Aug 2014 - mkillebrew

Back to the Armory

AR-180 - 5.56x45

The AR-180 is a gas tappet short-stroke firearm with a rotating locking bolt in 5.56x45mm of mostly stamped and welded construction. When the rifle is fired, gas is bled from the barrel at the front sight block. The gas passes through a tube with a ring on the end to seal the system. The front most section of the piston assembly moves under gas pressure to the rear until the ports pass the end of the gas tube, venting the excess. The rest of the assembly continues to the rear, compressing the piston return spring, and pushing on the face of the bolt carrier. As the bolt carrier recoils, a lug passing through it contacts the receiver, and pushing it along the track in the bolt carrier which rotates the bolt, unlocking it from the barrel. At this point the bolt group moves rearward until the twin recoil springs are entirely compressed, at which it returns to battery, stripping a fresh round from the magazine, and locking itself. The rifle disassembles in a similar fashion to the AR-15 with the exception of the rear. The botton on the guide rod assembly behind the rear sight is depressed, allowing the assembly to clear the edges of the rear sight, where it can be pushed in, disengaging itself from the lower receiver, and pivoting on the front pin. The front pin is retained with an integral detent ball and can be fully removed from the lower. The disassembly of the bolt group is accomplished by pushing the rear of the firing pin to relieve pressure on the cross pin that retains it. After the firing pin is removed, the lug that rotates the bolt can be pulled out, followed by the bolt itself. The recoil spring assembly also serves the purpose of retaining the top handguard on the rifle by passing through holes similar to those in the bolt carrier and receiver.

Right Side:

Left Side:

Right of Receiver - Ejection Port Closed:

Right of Receiver - Ejection Port Open:

Rear of Receiver, Note Takedown Button Rear of Sight:

Rear of Receiver with Stock Folded:

Left Side of Rifle - Stock Folded:

Receiver - Left Side:

Top of Receiver - Scope Mount Center:

Flash Hider:

Gas Block:

Receiver Group Separated:

Lower Receiver:

Lowre Receiver - Top:

Fire Control Group - Top:

Recoil Springs on Guide Rod Assembly:

Front Takedown Pin:

Charging Handle:

Bolt Group - Unlocked:

Bolt Group - Locked:

Bolt Group - Right Side:

Bolt Group - Front:

Bolt Carrier - Stripped:

Bolt Head:

Bolt Lug, Firing Pin, and Firing Pin Spring:

Bolt Takedown Pin:

Upper Receiver - Partially Stripped:

Upper Receiver - Top Handguard Removed:

Rear of Gas Piston and Spring:

Front of Gas Piston - Showing Three Separate Components:

Chamber Face from Underside - Notice Two Guide Rod Holes and Gas Piston:

Gas Tube:

Gas Piston - Disassembled:

Stamped Hammer: