Installation Instructions

ManualsBrandsAdams Arms ManualsFirearmsPiston Kit

Removal of Stock Parts (Impingement System)

1. Remove the upper receiver from the lower receiver.

2. Remove the bolt carrier and charging handle from the receiver.

3. Remove the bolt from the carrier.

4. Remove the gas rings from the bolt using a thin flat edge. Set the bolt and bolt carrier aside for later

installation steps.

5. Remove the top and bottom handguards from the barrel by pulling back on the delta ring and pulling the

handguards apart. If you don’t have standard handguards, remove any handguard(s) that might be on the

rifle.

6. Use a 3/4” wrench to remove the flash suppresser or muzzle break along with the crush washer from the

barrel.

7. Use a 1/8” hardened punch and a hammer to drive out the front sight pins that hold the sight assembly in

place. Some rifles will have tapered pins. Check both sides of the pins to determine if one side is larger than the

other and drive out from the side that is the smallest. Once both pins are removed, remove the sight

assembly/gas block and gas tube from the barrel by slightly twisting the assembly from side to side as you pull

it forward off the barrel. You can use a soft mallet (e.g. rubber, plastic, or brass) to tap the assembly off, if

needed.

8. Remove the stock front handguard cap from the barrel

Installation of Adams Arms Retrofit Piston System Components

1. Installation of Receiver Bushing:

Install the flash suppressor onto the barrel by hand tightening it to protect the

arrel threads during this step.

You need to make sure that the gas tube hole inside the receiver is clean and free of debris. Stand the uppe

receiver on a table with the barrel pointing downward and position the upper so that the flat top picatinny

rails are facing away from you. Place some type of heavy grease or preferably Vaseline onto the end of the

dowel rod. Coat the outside of the bushing with the grease to help it slide into the receiver hole. Push the

bushing onto the greased end of the rod with the external chamfered end of the bushing pointing away fro

the rod. Line up the bushing with the receiver hole and then firmly push down on the dowel rod to start the

bu ing. If you cannot start the bushing into the hole by using the dowel rod with hand pressure, line thesh

u ing up with the hole to the best of your ability and then, using a metal hammer, tap the dowel rod lightlsh

to start the bushing into the hole. MAKE SURE TO KEEP THE ROD STRAIGHT WHILE DRIVING THE

BUSHING IN! Drive the bushing in until the top edge becomes flush with the sides of the receiver hole.

Remove the flash suppressor from the barrel.

ote 1: If you plan on installing a free float handguard that does not use a delta ring, remove the delta ring

now.

Summary of content (4 pages)

PAGE 1
Removal of Stock Parts (Impingement System): 1. Remove the upper receiver from the lower receiver. 2. Remove the bolt carrier and charging handle from the receiver. 3. Remove the bolt from the carrier. 4. Remove the gas rings from the bolt using a thin flat edge. Set the bolt and bolt carrier aside for later installation steps. 5. Remove the top and bottom handguards from the barrel by pulling back on the delta ring and pulling the handguards apart.
PAGE 2
(The delta ring CAN be removed by using a Dremel with a cutting wheel to cut it off the barrel.) The proper way to remove the delta ring is to unscrew the barrel nut from the receiver and then remove the retaining ring from the barrel nut. The delta ring and spring can be removed from the barrel nut once the retaining ring is removed. Screw the barrel nut back on and tighten down to 30ft/lb minimum (not to exceed 80 ft/lb) to align the next slot in the barrel nut. 2.
PAGE 3
o. While you continue to hold the carrier in the receiver, work the gas block down towards the receiver until the space between the end of the sleeve and the back part of the gas block is approximately between .015” and .025”. (If you continue to move the gas block down towards the receiver it will start to push the carrier down. The rod will push on the carrier key, which will move the carrier out of battery away from the barrel extension.
PAGE 4
3. Installation of Handguards: Push the front of the bottom handguard into the bottom of the handguard cap. Make sure the front of the bottom handguard fits under the two notches on the inside of the handguard cap. Stand the upper receiver up on a table with the barrel facing upwards. As you push the bottom handguard into the handguard cap, pull down on the delta ring and push the handguard onto the barrel nut. Let go of the delta ring when the handguard is in place.