AR 15 Piston Conversion | Direct Impingement AR 15 vs Adams Arms Piston AR 15

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Windsor Arms Presents: A video showing the differences between Standard direct impingement system and the Adams Arms piston System. This will walk you through an AR 15 gas piston conversion; starting with a traditional direct impingement system andconverting over to an Adams Arms piston system. Enjoy the show!


Ever wonder how an Adams Arms AR 15 piston conversion system compares to a standard direct impingement system? Below is a video transcription of Windsor Arms comparing the two. Throughout the video the differences between the two systems are identified and showcased through a demonstration shooting of each.



“Hi this is Jarred from Windsor Arms, we are a veteren owned and operated small custom gun shop up in Vermont. We are going to do a demonstration, why the Adams Arms piston system is better than the standard direct impingement system.

We have our SOT (special operating tax) that allows us to make machine guns. So today we are going to do that test with this select fire lower that we completed at the shop. It keeps your gun cleaner, cooler direct impingement like the standard Bushmaster upper runs with the standard mil spec bolt carrier group and the gas comes out of the gas block in the front, down a gas tube, which is essentially an exhaust pipe going from the engine to the cab of the car; that makes no sense. In the Adams Arms piston system, the bolt carrier doesn’t get access to gas, carbon or heat from the gun operating. In the front of the piston system, you have four different selections: standard, supressed, off is to your far left and when you turn it to the far right it disassembles. So you pull it out, and your piston comes out and you can see your spring that gives it a maximum distance of a half inch travel. It stops carrier tilt; you don’t get any of this going on which other piston systems have. So we are going to take this and compare it to the direct impingement system and see how the bolt carrier comes out clean and hot between the two and we will give it a test. Thanks.


We will show the quick disassembly of a standard upper with direct impingement followed by the standard disassembly of an Adams Arms upper. Take your firing pin/ retaining pin and pull it out. The firing pin will come down. Turn your can pin and that is your disassembly for what we are going to do, all intensive purposes. This standard mil spec bolt has three different gas rings. You want to have those offset so they function proper. Offset the gas rings the way this system works is the gas comes up through the gas block on the front here down the gas tube and into the gas key. It goes down the gas key and hits the three gas rings. That makes the bolt unlock and rotate to the rear and then the whole bolt carrier slides to the rear. I will leave these parts out. Now, I will show you the disassembly of the Adams Arms piston system.


So here is the disassembly of the Adams Arms piston system. The bolt carrier, charging handle on the front. Here is the disassembly, you just pull out the piston and this is where the gas comes up through and then out here and you have the piston system operating. It has a half inch travel and it just has a spring to return it to the forward position. So easily you can just slide it back in and lock it back to the top postition. So the break down of the bolt carrier group is about the same, you just pull out your firing pin/ retaining pin, your firing pin will come out from the rear and your can pin, on this one, is a lot easier to remove because your gas key is not in the way. This bolt on here doesn’t need these gas rings becuase it is not needed. This spring is needed to help unlock and lock the bolt in the chamber or the barrel extention. Reassembly is just the opposite. You can see it automatically returns to the forward position. The reassembly of the standard direct impingement system is the same, it takes a little more time becuase you have to put the locking plug in and rotate it underneath the gas key and pull it forward. Put your firing pin in and put your firing pin/ retaining pin back in and your bolt assembly is back together.



So any AR 15 lower you can get an Adams Arms upper shipped to your door and can put it on yourself. To take down pins, you take the upper just like any other AR and you mate the upper and lower. The Adams Arms difference is that spring that’s on your spring inside the bolt carrier pushes the whole bolt carrier to the rear so it is easier if you made it up, push it down and they end at the same time. Right on. Goes in nice.


Today, we are going to take this 545 upper and put it through its paces. Hi this is Jarred from Windsor Arms up in Vermont. Two veterens, we like to shoot machine guns so we make them. We’re going to try this Adams Arms upper and see what she does. Not to shabby. Let’s take it apart and see how hot she got. I don’t even think it’s going to melt the snow. This thing stays so cool after firing it full lotto that you can pull it out and do whatever you want with it. It wins us over. I have a white shirt on for demonstration purposes. That is some carbon, but that’s not bad. Let’s compare it to direct impingement system.



We are going to go back with our eye and ear protection and run the direct impingement bushmaster upper on the shop select fire lower and see how hot the bolt carrier gets and how much carbon it has and get this thing a real test.


Wolf ammo is cheap and crappy, this is some good brass case American stuff. If you want to count your life on something don’t go cheap. First stoppage. Second stoppage. Ah catastrophic stoppage, the cartridge got jammed up above the bolt. So the stoppage, the bullet actually got jammed above the bolt so we are just popping it apart now. Cartridge looks alright but we are not going to run it. We will put this thing back together or pull it apart now, the bolt carrier is a little toasty, it was really hot over there, the whole upper receiver was hot. So we will run the rest of the rounds we have through it.


We got the direct impingement upper back together, we are going to run a full mag through it first, and then we are going to finish the mag that we had the malfunction with, so here we go. Not bad. Let’s take it apart and see if she is warm. I can feel through the receiver, the upper receiver, that it is pretty hot. It’s not hot enough that I want to drop it but it’s not real fun to hold. I think if I would have run all the mags; yea that ends hot. Let’s see what it does to the snow; that’s melting in pretty good. this melted in, this upper is pretty hot. Let’s see on the t shirt test how it does. The inside of the reciever is a lot nastier as well.




We are very patriotic, we love what we do. Let’s test this 545 Adams Arms upper. Not a single failure to fire. This thing is bad ass! From Vermont we say, we love America! Flawless operation, no failures, bad ass.”


As you can see, the Adams Arms AR 15 piston conversion system will keep your rifle cooler and cleaner while delivering superior cycling of rounds even through full auto fire… the choice is yours.

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