Looks great!  

Any word on the fitment yet?  Do we know if this will work with non-standard barrel nuts and fit over small ID free floats such as the Geissle Super Mod Rails, Bravo Company KMR and the Noveske NSR?

Curious about Geissele SMR rail compatibility too.
1.36" ID on those...

All of the above mentioned rails are around the 1.35ish range.  They also all use a non standard un-timed barrel nut which from my understanding prev. systems bushing had an issue with.  Really hoping that has been overcome in this model.  If so I say winner winner chicken dinner!

AA states that the XLP system requires a standard mil spec dimension barrel nut (same as their other systems). This system will fit over most rails, but will only WORK with rails that utilize a standard barrel nut.

I keep hoping someone will make a piston kit that will fit the KMR but due to size or the piston rod/bushing none seem to.  I REALLY like the KMR due to the insane light weight, 45deg keymod and that the clamping method does not force the barrel nut into the gas tube channel.

Owell, nice product anyhow

The XLP system is an improvement, no doubt, but you  pissed off a lot of people when you stated "fits under most rails" (when in reality it meant "work with rails that utilize a standard barrel nut", which is FAR less than "most", it's probably about 10% of FF rails, at most). While the gas block fitting under most hand guards is a step forward, it's not a huge step, as the barrel nut limits the FF rail selection. Baby steps. Sorry AA, I know you think your XLP was going to be the "game changer", but it's not. Yes, it now fits (gas block) under most rails, Yes... it won't work with most rails (due to the barrel nut). So you have gained about .05% rail use. Solve your barrel nut issue, then we'll talk.

so this fits under the samson evo rails? i have the keymod 15" and im probably going to pick one up. looks great!

also, will this work with 5.45x39?

Completely agreed, though I would say pissed off is a bit harsh....More like dissapointed and mislead by the Tactical_SHT youtube "Teaser" from Shotshow.  AA your right that you listened to your customers wanting it under there rails, but we meant any or most of the rails we choose, not just the ones with a standard barrel nut.  To quote the video "Look how little that thing is.  It will fit under ANY (stressed in video) manufactured rail system out there, any rail system any handguard system"  I dont know if you are affiliated with that blogger or not but the phrase "ANY" was out there in the public.  The product being shown in the video is the piston system and while also shown with a standard barrel nut, the verbiage leads the consumer to believe ANY means well ANY!  It would have been nice to see specifics on what is required of our rifles to use your system readily available and specs on your website.  

I think what is starting to PISS off the some people (myself included) is the general lack of real information, misleading information, and vague references or terms.  Add into this that when I called or emailed your company you could not provide a definite answer to several of my questions.   I got "Might" work, "Might" need modification, "Its got Lifecoat".  When I emailed asking what type of steel your bolt carriers are made of I got from YOUR Company "I do not know what type of steel are carriers are made with, but they are heat treated and finished in ion bond, you can pretty much just wipe them down with a rag.
We offer standard mil spec bolts in two finishes, one is a basic mag phos bolt and the other is our VDI lifecoat bolt."

When I asked if it will work with the KMR rail specifically I got "XLPs height from the top of the barrel to the top of the block is .625, from the looks of the rail it should work, although you may have to modify the barrel nut so that the drive rod bushing rests in the correct place." rather than just telling me "No it wont because you need a standard barrel nut or a barrel nut that is the same thickness as a standard nut" or "It requires the barrel nut to be standard thickness, here is a list of known manufactures non-standard barrel nuts that will work"

I guess the bottom line is you are loosing some of the trust of your customers, or at least this potential customer.  I want to do business with a company that tells me the facts about there products and does not cloud my purchase decisions with smoke and mirrors catch phrase's like "Lifecoat".  I want to know if it is 158 Carpenter or 9310 steel.  I want to know how it is finished, treated and/or coated.  I do not want to just take someones word that (to coin a phrase) its all good.

From what I have seen in my short time on AR15.com is that you DO stand behind your product if it is defective and for that you get a plus.  Most of the people who use your product are happy with its quality so that is a plus.  But I have also noticed on AR15.com is that many people are VERY particular with their rifles and what they trust with their lives.  While I dont believe any of this is done on purpose a little more transparency and less salesman "flash" would go a long way.

Tactical_SHT is not to blame for the misleading information. It was AA that stated it in a video that ar15com did of AA during Shot Show coverage. On ar15com youtube video covering AA you will see a AA team member state it will fit under ANY rail at 2:12: http://www.youtube.com/watch?v=ySpTxsgRghc. Not fair to blame Tactical_SHT when he got his information from AA.



Now on to the questions for AA: How does the XLP gas block disassemble? From the looks of it it can't disassemble through the front of the gas block? ...I could be wrong, just going by what I can see. If it doesn't disassemble through the front of the gas block how do you disassemble the one piece op rod/cup from the system for maintenance? Also beings this is an adjustable gas block how does one go about adjusting it without having to remove the rail?

Is this absolutely true or speculation?

Its true. They not only stated it on their facebook page, but in their forum on here: http://www.ar15.com/forums/t_2_293/245150_AA_XLP_piston_system_.html&page=2

But no where does it say that on there web page where you buy the product.  Something pretty important to be left out.

Piston Detail Screen

XLP Products Screen


So unless someone is on AR15.com and see's that thread or goes to their facebook page (Both places where you are NOT giving them money) you would not know.  If you didnt do your research first you could actually buy this with out being told of a MAJOR compatibility concern.  Add to that if you only watched the youtube video's on it where you hear them say it will fit under ANY barrel.  I would be pissed if I paid for it and found out after trying to install it or God forbid shoot it that it was not compatible.  Its this lack of information and transparency that is getting to be the "Typical AA behavior" that is putting me off with there company personally.  As the consumer I have to search the 4 corners of the internet to find the one or two places that are far from where they take my money they tell me crucial information that should be front and center.

Ok maybe im just reading in beween the lines but no where does it say it only works with a standard barrel nut, it says a standard barrel nut OR one with similar dimensions. Most barrel nuts have similar dimensions to fit handguards on standard upper receivers. If it needed the standard barrel nut for the op rod not to move that would be a different story.  Anyone care to disagree with me?

Yes most barrel nuts similar ID dimensions, however they are no where near the same dimension front to back (Muzzle to Chamber).  This is the dimension they are talking about.  Also you have to think about that a standard barrel nut supports the drive rod bushing on 3 sides (bottom and most of left/right).  The KMR would only support it on the bottom edge.  Something like a Seekins MCSR V2 Nut would work if milled to the same muzzle to chamber dimension as the rod passes through the barrel nut.  However this is a 1.8" ID free float.  

The drive rod bushing presses against the front face of the barrel nut to provide spring tension.  Thats why the thickness front to back is so important.

I dont think the op rod needs to be supported because shouldnt the upper receiver support the op rod? Im not trying to argue im just trying to understand why it wont work or if itll even work. Wish AA would come in and answer some questions so we can have a clearer understanding of what will fir and what wont.

Its not that the rod is supported (held vertically above the barrel) rather that the tension spring is held against the face of the barrel nut.  Here is someone's photo I found on google asking about the install.  Notice where the cup is pressing and how it only makes contact on the bottom of the bushing (thick part behind spring)



If the nut is too thick or too thin the tension on the spring and travel of the rod will be wrong.  Also since it is only held by the bottom there will be a force caused by the cycling of the weapon that might cause it to do this in time

As apposed to if a Barrel Nut is mil spec the teeth support more of the bushing front to back force.  Or if this were the same dimension front to back it would support the entire face of the bushing as it was pressed rearward as the rod goes through the Barrel Nut. (Again none of these are my photos and remain property of there respective source - I just found on Google)

OH ok, i get what youre saying! I thought it was just a matter of the barrel nut being supported and didnt think of the other factors involved. Thanks for the clarification Capt, really appreciate you taking the time to explain it to me

Backing up a couple of posts.  Pissed off is a very good way of putting it….

I’m pissed off for a couple of reasons.

First off in the following thread AA said they would release the information on AR15.com. But they didn't, they released the information on their website without so much as a hint of the product being available here on AR15.com.
http://www.ar15.com/forums/t_2_293/245150_.html&page=1

Then they have the nerve to post this here well after availability on their website  “Systems will be available as:“.  No kidding, same crap on your website.   But this was really their way of saying "Hell no you can't buy just the gas block".  
Is it backwards compatible?  Who the hell knows........and if it is, to hell with you loyal customer, just step right up and buy a whole new kit.

AA Get it together....

THIS style would actually be an ideal backing for their spring cup (as it would distribute the force equally around the spring cup), unfortunately... I'm not aware of one this style being made to standard barrel nut length (they are usually quite a bit longer).

So what they really need is customized bushings for other rails. Seems doable.
Baby steps. Got it to fit under all rails... now start working custom parts to work with all rails.
I like it

It would be great if they gave custom solution for each proprietary barrel nut, but that will NEVER happen.  I say never for several reasons but most of all cost.  It would cost less to R&D a whole new piston system than R&D 25+ different barrel nuts for the rest of the industry.  Further more if they did that less people would buy there new VDI Keymod Rail that they will over hype for the next 3+ months till it comes out.  I really have to say I am getting turned off from the Adams Arms brand by their marketing ploys.  I know they make a good product, but the smoke and mirrors approach to getting into my pocket and telling only the 1/2 story they want you to hear is getting old REAL FAST. (Video saying ANY while omitting the words standard Mil Spec Barrel Nut as Example)

Hard to say it will fit any rail using a standard barrel nut because that would not be a true statement either. I bet it won't fit Troy Bravo or Alpha rail. While there would be clearance for the gas block/piston cylinder one wouldn't be able to rotate the rail into position because Troy uses the anti rotation tab and the gas block and op rod will be too high into the picatinny rail milled out section to allow for successful rotation of the Troy Rails. Also, any rail that uses a standard barrel nut that doesn't have the picatinny rail section milled out on the inside will it will not fit either.


Edit still waiting on the answers from AA to my questions above with one more question added. I'm sure it got lost in the mix so asking again:
How does the XLP gas block disassemble? From the looks of it it can't disassemble through the front of the gas block? ...I could be wrong, just going by what I can see.
If it doesn't disassemble through the front of the gas block how do you disassemble the one piece op rod/cup from the system for maintenance?
Also beings this is an adjustable gas block how does one go about adjusting it without having to remove the rail?
You stated a Free Floating Piston System, what makes this a Free Floating Piston System?

I'll play guinea pig and try it on my urx4...order placed.

Your numbers are way off, spreading false information isn't really a good thing to do.

And what's way off? They've already stated (if you've read their other threads) that is uses a "standard mil spec dimension barrel nut". You do realize that most FF handguards do NOT use a mil spec dimension barrel nut, right? There are what... maybe 4 or 5 manufacturers that DO offer versions to use a standard barrel nut?
Sorry, but I stand behind my statement. Feel free to point out otherwise.

.05%? I rest my case.

Haha! Ok.. .05 was a stretch.. but you get the point. There are VERY few additional rails that would work with this system, vs the "most" that people were expecting.  No need to get hung up on the .05 (and the condescending attitude with "spreading false information isn't really a good thing to do"). You get the point, as others already have.

Magpul put out a mag (I forget which gen), that didn't work with a lot of Billet lowers. The issue has been fixed, but no one knew before hand.

I've been known to attack everything piston pretty hard, but I'm willing to take the attitude that it may just be a good idea to see what it'll actually fit. I've had several FF rails with stock barrel nuts.

True. The test will be once someone actually reviews it (would be nice if AA gave us more details eh). There are SOME FF rails that use standard barrel nuts (as I've already mentioned), but not many. I think people are put off because of all the hype about this system being able to utilize MOST rails, but you are right... we will have to wait and see what the real deal is (although, since they already stated it requires a standard barrel nut, I'm not too optimistic).
But "spreading false information"??... No. I'm stating what already has been said (and barrel nut info from THEM).

So AA, you have had a week to digest all of this feedback to your post.

Do you have any updates, answers or responses?

+1, I'm eager to give you my business. However, before you can ask us to buy your products we need to clarify some details. Please publish a list that includes all the rails/barrel nuts that will work with the XLP kit. Please, and thanks.

I'm going to take a stab at a guess here. My guess is the rails/handguards that will fit the XLP will be none other than the same ones that fit the current gen system... except ability to use LONGER length version of same rails. "Most rails", no. Same rails but longer lengths? Maybe. We'll see, but that's my guess

Here's an idea that I feel would work if it does not interfere with the operation. Use a support that can be fastened to the barrel like the gas block that will support the bushing, tension spring and rod.  Placement should be just short of any custom barrel nut and//or the barrel taper. They would have to push back the tension spring & bushing indentation on the rod to do this.   They can sell the kit for barrel type lightwieght, M4, Heavy, etc. What do you guys think?

So AA it's been 2 weeks now and your failure to respond speaks volumes......

They answered some more questions in their Industry Section.
Basically:
, yes, it requires mil spec barrel nut (or similar dimension). They specifically say "length", but I'm guessing the cup needs the mil spec type nut as well.
Yes, the XLP gas block will work with prior piston rods
No, it is not "pull through" (meaning system disassembly requires removal of the gas block).

But you are not going to sell it separately so we can retrofit our current systems?



No one is asking you to monitor the entirety of AR15.com, just follow up on YOUR post.

He just did.  Yeah, it may have been kind of slow, but they're working on it. If you'll notice his title, it's "product development manager", not "internet pimp".  AA has never sat on their asses, I'm sure he's damned busy.

My account is locked until I read and understand the rules.
http://www.ar15.com/tracker/manageIssue.html?issue=86364

I'm new to this so bare with me.  I have purchased the XLP system and a FF hand guard as well. I'm still waiting on my XLP to arrive. The rail I bought is the Bravo KMR. I absolutely love the KMR. It is unbelievably light. The barrel nut is mil spec but is longer than the stated .85". I guess my question to you would be, How long can the barrel nut be?  Max length? You say "similar length"  but how similar? If the KMR's nut works, will the bushing and spring fail with only the bottom portion of it on the nut? These are my concerns. I really want to keep the KMR and I'm hoping the XLP is everything you say it is.  Fingers crossed.

I've been looking to avoid pay $200+ on a handrail for use with the AA XLP  Gas/Piston System. Now that we know the product will not work under any handrail and not given a list of rails that would I have found an interesting handrail that can be used with the standard barrel nut $95-125.  They're carbon fiber with detachable rails and uses the standard barrel nut.  You will have to remove the barrel nut to install adapter that will key into the bottom notch of the barrel nut opposite of the gas tube notch and install the retainer plate with does not interfere with the barrel nut around the gas tube.  It looks like a pretty good fastening system and could probably have a aluminum one made for the same fastening system.  Not sure if any rails are included or if generic rails can be used.  Hopefully the AA XLP block will fit under this.  Do we know the minimum inside rail diameter for the XLP kit?

Here is the site that sells them:
http://www.cobratacsystems.com/collections/01a-free-float-quad-rails/products/cts-ultra-carbon-fiber-free-float-hand-guard-pistol-carbine-midlength-rifle-length

Install Video
https://www.youtube.com/watch?v=-31XXJE0rQU#t=67

I looked at the video and looked at pictures. From the pictures it doesn't look like the area under the picatinny rail is milled out. If it is not milled out I highly doubt it will work because at the end of the day even if AA's XLP sets lower it still sits higher than a DI Gas block due to the op rod/piston cup/cylinder which means it needs to be housed up in the milled out area of the picatinny rail. ANY RAIL that DOES NOT have the picatinny rail area milled out IS NOT going to work with AA's new XLP gas block. Same goes for any rails that need to rotate for install like Troy Industries WILL NOT work because the AA XLP still sets up in the milled out area of picatinny rail area of rails which will not allow for rotation for install.

So rails that wont work with XLP:
Those with proprietary barrel nuts unless it has the same dimensions as a standard barrel nut.
Those that do not have a milled out picatinny rail area.
Those that have to rotate to be installed such as the Troy Industries rails, etc.

(rail choices keep getting smaller and smaller)

Indeed.  That does not look especially robust.
 

AA, I think you keep either skirting (or are unaware of) a serious issue. It's not JUST the barrel nut length, it's ALSO the SHAPE of the barrel nut. The AA system requires a mil spec STYLE barrel nut WHICH HAS TEETH on it. The teeth are required to support the lower AND partial sides of the spring cup. Without those teeth, the cup will only be supported on the extreme lower edge and this will result in accelerated wear on the rod or potential failure of spring cup. Please STOP saying it just requires a mil spec LENGTH barrel nut. That is misleading.

Please someone report if this works with the DD lite/RIS rails.