Installation

Manufacturers Disclaimer
Adams Arms Inc. shall not be responsible in any manner whatsoever for physical injury or property damage stemming from criminal or negligent misuse, improper or careless handling, unauthorized modifications, defective, improper hand-loaded or reloaded ammunition, neglect or other influences beyond our direct and immediate control. If you do not understand the instructions in this manual, please contact Adams Arms for further clarification. If you are not completely familiar with the operation and assembly of the AR15/M16 rifle, Adams Arms Inc. strongly recommends that a professional licensed gunsmith install this product.

Always make sure your weapon is unloaded! Visually inspect to ensure that there is no ammunition in the chamber!

List of Tools Needed For Installation:

1. 1/8 inch Hardened Punch

2. 9/64 inch allen key, preferably an allen key socket

3. 5/32 inch allen key, preferably an allen key socket

4. if using allen key socket(s) ¼ inch ratchet

5. 3/4 inch wrench

6. Metal Hammer

7. min. 8 inch long metal dowel rod, 1/4 inch to 3/8 inch in diameter

   *On some occasions:

     Dremel with cutting disk
     Bench vise

Removal of Stock Parts (Impingement System)

1. Remove the upper receiver from the lower receiver.

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

3. Use a 9/64 inch allen key / socket to remove the stock bolt carrier key screws and pull off the stock bolt carrier key from the bolt carrier.

Note 1: We recommend leaving the gas rings on the bolt in order to stabilize the carrier as it moves into battery during firing.

THE GAS RINGS ARE A REQUIREMENT FOR FULL AUTOMATIC RIFLES.

(set the bolt carrier aside for the first installation step)

4. Remove the top and bottom hand-guards from the barrel by pulling back on the delta ring and pull the hand guards apart. If you don't have standard hand guards, remove any hand guard(s) that might be on the rifle.

c. Push the gas block back as far as you can towards the receiver. If not using hand guard cap, use the Spacer.

d. Stand the upper receiver up on a table with the barrel pointing up.

e. Tighten the gas block hex bolts with just enough pressure that still allows you to move the block from side to side on the barrel so you can align the gas block using the piston rod. You want the block to stay stationary on the barrel without any manual force.

f. Slide the narrow part of the rod into the front of the gas block, without the spring attached.

g. Make sure that the delta ring hole is lined up with the grove in the barrel nut and the receiver hole.

h. Slide the tip of the rod into the delta ring and receiver hole.

i. Push the rod down until it stops.

j. Insert the gas plug into the gas block; and align the detent button to the 12: O clock position. As you push the gas plug down, make sure you slide the plug into the drive rod sleeve.

k. Push the rod up sliding the sleeve over the gas plug until it stops.

Alignment of Gas Block

1. Make sure the gas block is pushed back tight against the hand guard cap during each step; if not using hand guard cap, use the spacer.

Note 5: If you have a flat top upper receiver, you can use the picatinny rail on the receiver to help align the gas block. Hold the receiver downward at a 45 degree angle and look down the receivers picatinny rail and visually align the gas blocks picatinny rail to it by slightly twisting the gas block from side to side.

2. Stand the upper receiver up on a table with the barrel pointing up. Try sliding the rod up and down a few times. The rod should slide freely up and down. If it does not move freely slightly twist the gas block side to side until you can slide the rod up and down freely. Once you find the correct alignment of the gas block, slide the rod up and down as you twist the rod to all 4 positions at 12, 3, 6, and 9 O clock. Make sure the gas block is pushed back tight against the hand guard cap/spacer.

Be careful to hold the position when you find it.

Note 6: If using allen key to separate gas block legs: As you keep the block in position slowly unscrew the cap screws and remove the allen key. Screw the cap screws in the standard direction.

3. Slowly tighten the cap screws on the gas block while you hold the proper alignment position for the gas block. Alternate back and forth as you tighten the screws. Make sure the gas block is pushed back tight against the hand guard cap/ spacer.

* If you tighten the hex bolts too hard and fast you will twist the gas block out of alignment.

4. Completely tighten the gas block cap screws to 40-50 ft lbs and repeat step 2.

5. Remove the gas plug and rod from the gas block. Slide the spring and bushing onto the rod and reinstall into the block.

6. Install the crush washer and flash suppressor/muzzle break onto the barrel. Tighten down the break.

Installation of Hand Guards

1. Push the front of the bottom hand guard into the bottom of the hand guard cap. Make sure the front of the bottom hand guard fits under the two notches in the inside of the hand guard cap. Stand the upper receiver up on a table with the barrel facing upwards. As you push the bottom hand guard into the hand guard cap, pull down on the delta ring and push the hand guard onto the barrel nut; let go of the delta ring when the hand guard is in place.

2. Push the front of the top hand guard into the hand guard cap. Pull the delta ring back and push the top hand guard onto the barrel nut, let go of the delta ring when the hand guard is in place.

Installation Complete.

Gas Position Setting and Carrier Timing

We recommend using FMJ Winchester white box or Federal m193 ammo for gas setting testing.

Our piston system was designed for rifles that were built to mil-spec. Most importantly rifles that have their gas port hole drilled to mil-spec. Because of manufactures differences in gas port hole size, our piston system was designed with three different gas settings. These settings are found on the gas block. Looking at the front of the gas block you will see four different groves where the detent button in the gas plug will fit once the plug is installed in the gas block. The grove at the 9 O'clock position is the insertion grove. The groove at the 12 O'clock position is the full gas setting (as pictured). The 1 O'clock position is the lower gas setting. The 3 O'clock position is the off setting. If the manufacture of you rifle drilled the gas port hole to the mil-spec size (size changes depending on barrel length) the full gas setting should work best for the proper cycling of our system (proper velocity of the bolt carrier). Some manufactures drill the gas port hole size out larger than mil-spec. They do this in order to get more gas (than is required) running through the impingement system, so there is no chance of the rifle not working with weak pressured or non-brass ammo. If your rifle is made by one of these manufactures then our system will cycle faster (high carrier velocity) than what is the proper velocity.

The way to determine if your rifle is cycling to fast or slow is to watch were the spent round casings are landing after ejection. If the case is bouncing off the case deflecter and landing at 12:30 to 2 O'clock then the carrier is moving at to high of a velocity. You would need to turn the system down to the lower gas setting. You want your cases ejecting at 2:30 to 4 O'clock. Ejection at 4 O'clock (as pictured) should be a forceful ejection and not a lob. A short lob at 4 O'clock is to slow of a carrier velocity. The low gas setting may be used for suppressors, if needed. The off gas setting will shut off the system and stop the cycling of the rifle.

This activity should be repeated as often as possible.

Full Auto Fire:

There has been situations were we have experienced carrier bounce during full auto fire. Carrier bounce is caused by the carrier moving to fast as it moves forward into battery (to high of a velocity), were the carrier hits the barrel extension and bounces off the extension (out of battery) as the hammer is hitting the firing pin. When the carrier is out of battery the firing pin can not hit the primer to ignite the propellant. When you experience carrier bounce the rifle will stop running during firing, the hammer will be forward with a live round in the chamber. If you look at the round in the chamber you will usually see light primer strikes.

To fix carrier bounce use a heavier buffer than what is in the rifle until you get the bounce to stop. Buffers are made with different weights, that are denoted on the face of the buffer from lightest to heaviest: nothing on face, H, H2, H3, X.