View Full Version : Adams Arms Kit Review

6 December 2012, 12:32
A few months ago, I was at the range shooting one of my carbines suppressed with an AAC 762SDN-6. Iím a left handed rifle shooter, so I was getting gas blown back in my face all day long. As much as I like shooting suppressed, I just about had it with all the gas in my face. Now Iíve never been a big fan of Pistons as I just didnít see what problem they solved and I have complete faith in my DI guns. However, the draw of less gas while shooting suppressed had a lot of appeal to me. I know that Pistons have their issues, weight, front heavy, carrier tilt, proprietary parts, ect.

After some ďresearchĒ I decided I would try out an Adams Arms conversion kit. This was mainly due to the fact I had an unfired, unused mid-length upper that I could donate to this conversion. The upper itself is just a plain jane Palmetto State Armory upper with a mid-length 5.56 barrel 1/7 twist with chrome lining. The upper is not marked in anyway. I also decided instead of taking my usual garbage pics, I would enlist the help of the one and only Stickman. So thanks for the help Stick.

I went to Rainier Arms, and after talking to some of the knowledgeable folks there decided on this Adams Arms Kit:


To me, isn't surprising they had a hard time keeping these in stock as they are a popular kit from everything I've seen and read. The kit retails for $279, but I paid a few dollars less with the LE/MIL discount. The Adams Arms Kit also features:

Lifetime Warranty
Adjustable Gas Settings for Suppressed Fire
Full Auto Rating
Compatible with 5.45x39, 5.56, 6.5 Grendel, and 6.8 SPC
Installs in less than 30 minutes

The Kit comes with:

Gas Block and Plug
Bolt Carrier
Instructional DVD
Modified Handguards
Drive Rod Assembly

I also purchased a Centurion Arms 9.0 Mid-Cutout Rail (THIS WILL BE IMPORTANT LATER) http://www.rainierarms.com/?page=shop/detail&product_id=2734 The reason I went with the Centurion Rail is the new C4 rails were Adams Arms compatible. Itís not on the official list on the Adams Arms website, but a few emails back and forth to Centurions excellent customer service confirmed this fact. The new C4 rails that are compatible are designated by an ďAĒ mark on the top of the rail. For instance, this rail has a ďT16AĒ laser engraving on the top rail vs just ďT16Ē to denote the compatibility. As a side note, the rails I purchased did not include the mounting screws. An email to Centurion fixed that problem, as not even 30 minutes later, I received a reply and a promise to mail the screws immediately.

Once I had the items purchased, off I went home to put it together what I could. First the front sight post, Delta Ring assembly, and A2 birdcage had to come off. The barrel nut stays on as it is needed for the Centurion Rail installation.


Next, the gas block fits right over the barrel once the 2 allen head screws are loosened. You can tell Iím not Stick, as Iím relegated to North Face peasant wear, while heís always sporting Arcíteryx bling. Sorry, Stick, had to get that jab in there.


Then the operating rod is assembled. There are 3 sections, and I was in fact surprised how well made they appeared to be. My initial thought when looking at them was, these are flimsy.


Then it was put together, not much to it:


Next, I inserted the operating rod into the gas block and into the upper receiver. I first torqued the barrel nut correctly using a torque wrench. The operating rod went into the receiver after it was properly aligned. I got lucky, as once I torqued the barrel nut down, it already lined up with the gas tube entry.


There is also a step where you have to place a metal insert into the upper receiver into the gas tube opening from the inside, but there was no good way to take pictures of it, and itís very self explanatory. I will also point out the Adams Arms instructional DVD is one of the best I've ever used. The instructions were very clear, with good diagrams, and animations to assist the novice AR user.

At this point, I installed the rail, well at least attempted to install it. I quickly figured out the Centurion cutout rail would not fit. It simply doesnít have enough room on the bottom due to the large gas block. Oops, there goes my plan. However, all was not lost. I swapped out the cutout rail for a regular Centurion 9.0 Rail.


Once I got the top rail on, it was obvious, this was the right way to go. Now if you want the C4 9.0 Cutout rail to work, they will, but you will have to use the Adams Arms Lite Kit found here: http://www.rainierarms.com/?page=shop/detail&product_id=2921 or the pinned model.


This is what I love about Centurion Rails. They are solid rails, but utilize an easy 2 piece free floating design. The 2 halves simply clamp on the standard barrel nut. 6 allen head screw turns later, and you have one of the best rails on the market. Iíve slowly converted many of my existing carbines over to the Centurion C4 rail, they are simply worth every penny in my opinion.


Once the rails were on, the only thing left to do is put together the Bolt Carrier. Adams Arms comes with the carrier, but you have to supply several items:

Cam Pin
Firing Pin
Firing Pin Retaining Pin

The kit also comes with a spring you have to install on the bolt. Not a big deal and very easy to do. Once you put those items together, just like you would a standard DI BCG, install it with a Charging Handle and youíre done.


The finished rifle with Gear Sector vertical grip, handstop, Magpul MBUS, Centurion Arms lower, and Compact ACOG. Lastly, I added the AAC Brakeout as I will be shooting this suppressed, which of course for me, was the entire point of this conversion.


I will update this rifle periodically as Iíll be shooting 6-7k rounds through it, much like my Rainier Arms Carbine to see just how much I like or dislike the gun, kit, rails.