Adams Arms Gas Piston Conversion Kit Assembly

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This video will be going over how to install the Adams Arms gas piston conversion kit on your standard/ DI AR 15 rifle. For your convenience below is a transcription of the video tutorial.


“Hey it’s Darrel,


We are going to put an Adams Arms gas piston system on a direct impingement mid length AR 15. We have cleared the weapon, there is a new magazine in place, and we have visually checked the chamber. Chamber is clear; let’s get started.



We are going to pop the pins out that connect the lower receiver to the upper receiver. Alright, so what comes with the kit is the Adams Arms gas block itself, this is the part that replaces the triangular front site base gas block on a standard AR 15 rifle or carbine and it is adjustable, different positions; gas setting positions. This is the rod that is going to replace the direct impingement gas tube. This is the Adams Arms bolt. It is different than a standard AR 15 bolt; the key is completely different. This is where the rod strikes the key. This is the bushing that goes into the receiver and goes into this hole that normally the DI tube goes into. This rod rides through that bushing. It is stainless steel so it doesn’t wear out the aluminum on your upper and then this spring goes in the back of the bolt that comes out of your rifle. This kit doesn’t come with its own bolt; it comes with the carrier but not the bolt. This fits on the back of there, we will be removing these gas rings in just a second, but that is basically what you get in the Adams Arms gas piston system.


Alright, what we need to do next is change out the bolt out of the bolt carrier. Adams Arms supplies a bolt carrier with the kit. As you can see the key, this is the key on a typical AR 15 bolt, the key is different. Rather than a gas impingement tube coming inside the key which blows the bolt back I showed you earlier. The piston rod hits this flat space here and that’s how it operates. But we are going to use the bolt from your AR 15, and we are going to retrofit it into the Adams Arms bolt carrier. So let’s do that real quick.


Alright, so we are just going to pop out the retaining pin; it comes right out. Take out the firing pin; comes right out. Which allows us to rotate the can pin 90 degrees. It can’t be in the full position it has to be back. Rotate that 90 degrees. It pops out. We are going to pull the bolt out of the bolt carrier and the next step is we are going to remove these gas rings that are on the back of the bolt right here. So what we are going to do is, using a pocket knife with a fine blade, just peel and it comes off. Alright, so now that we have removed the gas rings from the bolt we are just going to take the bolt spring. It goes right on the back just like that.


Alright, what we need to do to take off the gas block and try to get a front site base on the AR 15 is find out which side of these taper pins are smaller because you have to push the opposite direction. If you push the fat side you are going to be tightening it. On this particular model, I think on most 15 models, we are going to be punching from this side. We have already pre punched these to make them just a little more easy becuase these were fairly tight. Just use a 5 30 seconds punch. Typically, you could use a block of some kind, but I’m just showing you that without a block you can make this work if you have just a wooden handle of another hammer you can lay that down and as long as you have a nice surface.


So now that the pins are out, what we are going to do is, we have already loosened this, the A2 off flush hider and the crush washer. We are just going to gently tap the site off, kind of twist that off there. We are also going to take off the cap that holds the part up front the front handle on. So this is what the barrel looks like without the typical radar front site base on it. Here is the hole that your gas goes in through and we are going to put the A2 hider back on. Mainly, it is just a thread protector so that when we are assembling the rest of the components we don’t jack up the threads on the barrel.


Next thing we are going to do, is take the stainless steel bushing and it is a little difficult to see but it is going to go into the hole right there, and then this tool is going to be the part we are going to use to drive that in. So what we are going to do is take a little bit of white grease and we are going to just slightly grease up the bushing before we put it in. We are also going to put a little bit on the steel dowel we are going to use. The idea behind that is this will hold on there as we put it into the receiver. We will get it set in first making sure it is going straight in and once it is going straight in we can push it in and then use a little more force with a hammer and tap it in place. We are going to just gently tap this in. Make sure we keep it in alignment as we do that. Alright, so after a little bit of tapping we have got the bushing slightly below flush into the holder inside the upper receiver and there we go we are ready for the next step.


Next thing we need to do, is take the cap that comes with the modified hand guards, and this is just the hand guard cap that holds the hand guards together, and slides onto the barrel just like this. It is modified to fit the gas block so it’s special you can’t just use your regular cap. After we have the hand guard cap in place, we are just going to slide the Adams Arms gas block on and then tighten it just barely. Not to tight so that if I adjust it, it stays in place. Then I’m going to look down, and it is actually right on. Just visually inspect it to make sure that the lines on the picitiny are totally parallel with the lines on the top of the receiver. So once you more or less have the gas block aligned with the upper receiver, just make sure it is all snug. Now, we are just going to try and make sure we are aligned with the drive rod, make sure that all the components of your delta ringer have the holes lined up.


Now that we have visually aligned the upper receiver with the picitiny on the gas block itself, we are just going to check and see if this moves freely and it does. Now, there could be two things you may need to adjust here: either this isn’t perfectly aligned with the upper receiver, or the timing could be slightly off on your barrel nut. So you would need to use your armorous tool and you could visually see if there is a little gap on this side and it is touching on that side it might be binding there either way as I just had to do, you might need to adjust the timing ever so slightly to make sure you are moving freely there. So now let’s move onto the next step.



So what we are going to do now is put the charging handle in and the modified bolt. Put this forward, we need to put a little bit of pressure on the back of the bolt because remember this is in here with the spring and the assembly, and then what we are going to do using two business cards is check the gap right here and the gap we are checking is in between the drive rod and the gas block itself. If you don’t have any other way of checking it, you can take a couple of business cards and just see that you have clearance there. All you need is a couple of business cards real easy way of doing that, if those don’t fit in there freely then it’s too tight.


Now that we know the alignment is correct and the piston is moving freely, the drive rod is moving freely we are going to go ahead and tighten this down or just until it is really snug. So what we need to do next is take the gas plug back out, take the drive rod back out and put the assembly back together and the drive rod assembly goes this way and this goes back in here. There we go.


With our kit came the modified hand guards which are cut and designed to be used with the gas system, so we already installed those and last but not least we are going to put a fresh crush washer on and reinstall our A2 flash harder and then we are just going to use our armorous tool to get the timing right on it. Now that we have the upper completely assembled, we are going to go ahead and put it on the lower. Push the first pin in first, and remember the bolt now has a spring on it so we are going to have to hold the back of the bolt carrier in as you assemble it. After we do that, we want to do a couple of checks to make sure it is functioning; seems to be functioning well and then of course you want to attach your optics back on there. Put your back up site back on and the magnification you want and you’re ready for the range.”


I hope this video helped you install your own Adams Arms gas piston conversion kit. For more information on the kit itself or any of Adams Arms’ products please visit

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