Adams Arms Piston Kits/Voodoo Innovations barrels?

[Gaspipeshooter]

Anyone have any experience with the Adams Arms piston kits? Considering a piston kit and 11.5" barrel for my pistol build.

[UWone77]

I have a Voodoo/AA kit, but haven't installed it yet.

Why do you want to go with a piston kit? Especially on a 11.5? Frankly, I am less than impressed with the AA Kits. One of the two kits I used, the op rod was stuck at the 500-600 round mark. No amount of lube, kroil, tapping with a mallet would get it loose. The only piston I would consider at this point based on experience is the PWS.

[gatordev]

I built a 11.5" upper with a Mega-branded AA kit and have had a good experience with mine. This particular one was made to fit Mega monolithic uppers, which is why it's branded Mega, but it's still an AA kit. I have just over 1000 rounds on mine and the two issues I initially had was getting the bushing for the rod into the receiver (it was really tight), which made it hard to get it even. This in turn made the rod rub and not operate completely freely. Once I took a few more whacks at the bushing and made it even in the upper, everything lined up and there was no more rubbing. I've had zero carrier tilt issues on mine.

All that said, I built it to see what an Op Rod gun was all about first hand rather than reading about how it was 100% concentrated evil on the internet. I'm glad I built it, but I'm not convinced it's really doing anything better than my DI guns other than shooting with almost no recoil impulse when it's suppressed. I'll keep the one I have, but I don't really plan on building or buying another one.

What UWone describes sounds like the bushing or gas block got out of alignment, though I'm sure he troubleshot that, so maybe it was something else.

[Gaspipeshooter]

I have a Voodoo/AA kit, but haven't installed it yet.

Why do you want to go with a piston kit? Especially on a 11.5? Frankly, I am less than impressed with the AA Kits. One of the two kits I used, the op rod was stuck at the 500-600 round mark. No amount of lube, kroil, tapping with a mallet would get it loose. The only piston I would consider at this point based on experience is the PWS.

My thoughts on a piston kit would be to be able to adjust the gas when suppressed. That was my primary consideration.

[UWone77]

My thoughts on a piston kit would be to be able to adjust the gas when suppressed. That was my primary consideration.

Yeah, that was my original plan too. But my gas plug on one of my AA uppers is stuck on the non-suppressed/"normal" position. Won't budge. I guess I won't be shooting this suppressed!!

[WHSmithIV]

I don't have experience with one 'yet'. However, I just won the one I designed in the Gunstruction design competition. I'll let you know what I think about it after it arrives :)

[Gaspipeshooter]

I don't have experience with one 'yet'. However, I just won the one I designed in the Gunstruction design competition. I'll let you know what I think about it after it arrives :)

Mine is sitting on the bench; 5.56 - 11.5" Voodoo Innovations medium contour barrel and the Adams Arms piston kit. I've got the lower all ready to go, including the Sig Tac pistol brace. Just need a handguard and muzzle device to be operational.

[Swatbwana]

My thoughts on a piston kit would be to be able to adjust the gas when suppressed. That was my primary consideration.

I used an AA kit on a DD 10.5 barrel with the DD 9.5 FSB rail works excellent suppressed .

And runs like a beast on a registered lower as well.


Sent from my iPad using Tapatalk HD

[Gaspipeshooter]

I used an AA kit on a DD 10.5 barrel with the DD 9.5 FSB rail works excellent suppressed .

And runs like a beast on a registered lower as well.


Sent from my iPad using Tapatalk HD

Good to know you have had a good experience with yours. I need to quit waffling and decide on a handguard and muzzle device so I can wrap mine up!

[Hmac]

I'm looking for a good, lightweight melonite-coated barrel. I live right here at Huldra HQ and the principles of the company are guys that I shoot with regularly. The Adams Arms barrels (and I presume Voodoo Innovations) have served them very well from a longevity and reliability standpoint and I'm thinking that's the direction I'm going to go. Sionics is interesting, and cheap, but in the absence of any longevity info I'm going to pass. Apparently, not all melonite-coated barrels are created equal.

[Gaspipeshooter]

Well, other than a muzzle device and a handguard, my piston pistol build is ready to go.

http://pic100.picturetrail.com/VOL609/13465559/24585238/410038408.jpg

I order my handguard from Midwest Industries yesterday, still trying to decide on a muzzle device. I may throw an A2 birdcage on there for now and see how she runs. Grip and FCG are temporary as I had them laying around. Thinking an ALG ACT FCG and maybe an Umbrella 23 grip...

[WHSmithIV]

Folks the technical nitty gritty of this is pretty simple. The barrel is fine - Yes, the Voodoo barrels are a bit expensive. The barrel though isn't really the question. Any reasonably decent melonite or nitride barrel will basically last as long, be as accurate and functionally equivalent.

It is the piston system that is the question though.

Let's take a walk down memory lane for a moment. The M16 was designed back in the 1960's. There is even a photograph of President Kennedy holding one of the first prototypes. (I'm guessing if such a picture would be taken today it would be Obama holding a golf club and smoking a joint) Sorry folks I just couldn't resist that one in the context of what I'm writing.

The M16 was a fully automatic machine gun. Select fire 3 round burst did not exist then yet. The M16 was full auto or single shot semi auto - that's it.

The M16 was also marketed to good old Joe public USA. The full auto function was removed (it is a trigger group part only anyway) and Joe Public Citizen now had the same new technology rifle that our Army had adopted. That's a good thing too. Because it is ultimately Joe Public Citizen who would have to be called upon to defend our USA from invasion and the M16 / AR15 is very good rifle.

So, fast forward 35 years. What was the worst problem of the 1960's design? The design is pure genius and very simple, but, it does have a problem. The M16 or AR 15 uses the burning fumes from the explosion in the cartridge to fire the bullet to also reload itself. Those burning gasses do have carbon and that and carbon is an element that will build up in a very short time. Our Viet Nam vets were told they would never have to clean the rifle and what they found out was that their very lives depended on keeping it VERY clean daily.

So, fast forward another 40 years. Someone understood the fouling problem from the gas operation, so a piston driven - still gas fired - design was invented. This is VERY helpful with keeping all that nasty carbon after burned gas fouling crap from going back into the upper receiver and to ultimately the bolt and firing pin. However, that still is the same gas that drives the semi automatic function. On the plus side though, you don't have to take apart he entire rifle to clean the carbon fouling from firing gunpowder. With a piston system no gasses go back into the receiver so all the fouling is localized in the gas block. That does make sense, but it does add extra mechanical parts. It also brings up the question as to how easy it is to clean that block that's driving the piston.

There is a secondary effect of using a piston instead of the gas to move the bolt carrier back to cycle the action. Gas expands equally in all directions. A mechanical rod doesn't. The physical movement of the rod puts unequal pressure on a bolt carrier and that does lead to extra wear in an upper receiver.

[Gaspipeshooter]

From a physics/mechanics point of view, the gas key and gas tube contain the gases until the BCG has moved far enough rearward to separate. The pressure exerted on the BCG by either gas or a piston rod is concentrated in basically the same area. I don't have first hand experience with a piston set up, (yet!), but it seems to me there should not be a tremendous amount of difference in BCG tilt.

As for cleaning, I'm thinking from what I have seen so far I'd much rather clean the gas block and piston. I know it is comparing apples & oranges, but having run 10s of 1,000s of rounds through Remington 1100s and 11-87s in my trapshooting days as well as waterfowl hunting, I learned something from that experience that I will apply to the piston set up. I ran, (and still do run) my Remingtons "wet", that is with liberal amounts of Breakfree CLP applied to the gas system parts. The carbon is essentially held in suspension, and for the most part wipes right off. I'll be trying that on the piston system to see how it works.

[Gaspipeshooter]

Finished product at the "functional stage". The pistol grip, FCG, and muzzle device will get changed eventually, but at least I can run some ammo through it now.

http://pic100.picturetrail.com/VOL609/13465559/24585238/410053563.jpg

The handguard and piston gas block:

http://pic100.picturetrail.com/VOL609/13465559/24585238/410053564.jpg

[Gaspipeshooter]

I got a chance to stop by the range this afternoon and give the pistol a quick function check. I was very pleased with it. I only ran two 30 round mags through it, but on measured firing and rapid fire it ran very smoothly. Now to decide on a sight...

[WHSmithIV]

How well did that Midwest Industries handguard fit with the piston running under it? It looks good too.

[Gaspipeshooter]

How well did that Midwest Industries handguard fit with the piston running under it? It looks good too.

I like the look, and it fits very well too. The drive rod has plenty of room inside the handguard. Just eyeballing it I'd say better than 1/16" on each side of the fat end of the rod where it goes over the gas plug. As an experiment, I dialed the gas down to the "suppressed" setting, and it vented enough that the bolt did not cycle. I like the idea of that for working with new shooters so it essentially becomes a single shot. Much safer!

[UWone77]

These guys are serious about producing barrels!


http://i1334.photobucket.com/albums/w654/richardkim0177/adams-arms-available-barrels_zps426d7c84.png (http://s1334.photobucket.com/user/richardkim0177/media/adams-arms-available-barrels_zps426d7c84.png.html)

[Ride4frnt]

Think I may be using the voodoo 11.5" on my pistol

[Gaspipeshooter]

Think I may be using the voodoo 11.5" on my pistol

I used the 11.5" medium contour for my build.

[bwalshx314]

I have a friend who used the 11.5 for a build and he said he loves it, looking to take a look at it soon.

[jrhathorn]

I looked at all the piston conversion kits I could find for one that would work with the front sight base on one of my AR-15s. It seems the most recommended kit is the Adams Arms but they require a replacement for the the gas block. That is good if you really need to adjust the gas but that does not concern me in this case. My rifle is a Model 1 Sales that uses a DPMS upper receiver and an ER Shaw carbine length barrel. I removed the gas block when I bought it and installed the FSB (pinned through slots in the barrel). Before deciding what to do about the conversion, I had installed a 7" free float handguard I like and wanted to keep. So, I found the Osprey OPS-416 which looked like it would work with either a gas block or the FSB. I bought it on the chance all would work together. In order to keep the one-piece free float handguard and install the op rod, I had to remove the FSB. That allowed installation of the bushing in the receiver and the op rod through the barrel nut. Then I put the handguard over the barrel and op rod. Next I installed the piston chamber into the FSB. After that I installed the FSB with the chamber/chamber rod on the barrel over the gas port on the barrel lining up the chamber to the op rod. Last, I aligned the FSB with the pins and pinned her up. My concern was the room for the piston chamber and op rod beneath the handguard. It was close but there was enough room for to operate freely. There is no documentation for a handguard other than the expanded one that comes with the kit; however, this build went well. I have had no problems with it at all after several hundred rounds with Wolf ammo, and other better brass cased stuff. The carrier tilt is not a problem so far and I have no reason there will be any. I have a couple of other ARs I want to convert. If anyone know of other kits that work with the A2 FSB I would appreciate a reply. I like the FSB and the A2 carry handle on my ARs. I put an NCStar scope mount on the carry handle for my scope. All is well with the Osprey but I would like to try something else. The gas piston is a clean running machine!

http://www.mosinguy.com/wscope_right.jpg

[Hmac]

I had been planning on a Voodoo barrel because I wanted a lightweight melonite-coated 16 inch midlength. I was toying with the idea of a Sionics barrel at $100 less - decided to take the leap of faith...and they're out of stock, apparently. Voodoo it is, I guess.

[FortTom]

I had been planning on a Voodoo barrel because I wanted a lightweight melonite-coated 16 inch midlength. I was toying with the idea of a Sionics barrel at $100 less - decided to take the leap of faith...and they're out of stock, apparently. Voodoo it is, I guess.
Which barrel did you get? A couple of projects back I bought a Voodoo Ultra Lite. I was concerned that the heat and harmonics of such a thin profile barrel would make it a CQC rifle, or accurate at 50 yards or less. I would have taken 3" at 100 yards as far as "combat" accuracy. Not that it matters, it also has a VG6 Epsilon brake screwed on. For it's maiden voyage I was really just going to break it in a bit, then break it down, clean and lube every thing, and go back to the range again. Actually, I was amazed at the accuracy of the barrel, using inexpensive Wolf Gold (uses brass cases and copper/lead FMJ 55 grain bullets). I actually built the whole rifle with "light weight" being the entire theme. Since, I've shot slightly over 1" groups at 100, 5 round groups, I think it was. I'm sure it's "combat accurate" at ranges of at least 200 yds.

If it matters, the barrel isn't dimpled, I had to mill my own flats for the set screws on a Bridgeport and that was a bit hairy. The table had problems, and a friend of mine worked together with me to get it perfect.

Anyway, although based on just one barrel, I am pretty impressed, and a heavier weight barrel should alleviate any concerns about accuracy or harmonics inherent with a very thin profile barrel. My barrel is a 16" mid, and I got a melonited gas tube from them also. Will be interested in hearing what profile barrel you bought and how it performs.

FT

[Hmac]

Pretty interested in the EVO ultra light 16 inch melonite. It will go under a KMR 13 rail I have sitting around. I just have to find a gunsmith that will pin a .625 gas block on a nitrided barrel. It doesn't appear that ADCO does. IIRC, Rainier used to for a few dollars extra, but I can't make heads or tails out of their new website relative to gunsmithing.