Alright, for my piston conversion, I've narrowed it down to PWS or Adams Arms.  I was just wondering if I could get a bunch of different opinions on the pros and cons of each and what you'd recommend.  The things I wonder about:

1) Reliability
2) Robustness (how strong is the piston rod in each...I just wonder because the PWS looks a little thin and fragile)
3) Ease of conversion
4) Accuracy
5) Recoil and smoothness of action

Any and all opinions welcomed.  Thanks!

It will be extremely hard for anybody to really give you good answers to these questions.  When comparing these two systems, nobody has done a scientific study to answer the items with regard to accuracy and the hard to measure "smoothness".  Accuracy might be much more a function of the underlying gun... i.e. I do a Adams Arm conversion of a Colt, you do a PWS conversion of a Hesse.... My Colt shots better.... does that mean Adams is better than PWS ?

Some things I can tell you about my Adams Arm conversion.  I took a brand new LMT carbine and put the Adams carbine length kit on.  I did NOT get the kit with carrier.  I converted the LMT carrier.

1. Reliablity - Dunno... personally I have 200 rounds through mine.  No failures of any type.  Many other Adams owners have reported zero failure conversions (i.e. many hundreds or thousands rounds with no issues)

2. Robustness - I don't know how strong the rod is.  It must be quite strong to last even 200 rounds, but will it last 9,000 ?  Who knows

3. Ease of Conversion - Adams can't be beat, I don't believe.  It is a 1 hours install for a novice who take their time and READS THE INSTRUCTIONS carefully.  I think Adams does themselves a disservice by suggesting this is a 20 - 30 minute conversion.  Then the first thing you see when you look at the instructions is to READ EVERYTHING VERY CAREFULLY.  Well, a very careful read of the instructions, twice so you are sure, followed by step by step reading and converson is at least an hour.  Take your time.  What's the rush.  KEY - NO CUTTING, NO
PERMANENT changes to the rifle.  HUGE in my eyes.

4. Accuracy - Seems as accurate as any of my carbines.  Not any better, not any worse.  I shoot only irons, so 100 yard testing is more a function of my eye.... I see no degradation over normal carbine

5. Recoil and Smootness - Totally subjective measure... so how do I answer?  Mine is a carbine.  Carbines are sharp and pack a punch.  The piston is still sharp and packs a punch.  I have not tried turning the regulator down.

Other thoughts - As I was building it, I was thinking "Damn nice kit... well thought out, well made, very straight forward".  I still think that.  The kit is very simple, and rod is well supported.  I have a lot of faith that it will last a long time.  I like it, CLEANING IS SOOOOO NICE.  I converted mainly because guns are a hobby, and who wants every gun working the same way, so it was fun, and I like having a conversion AR.

More thoughts - Smith and Wesson is coming out with a piston gun, and it is based on the Adams kit.  That should tell you a lot.  I am sure Smith looked at all the kits once they decided not to design from the ground up

And..... Spikes has two new uppers, both of which look damn nice, one based on pinned version of the Adams kit, the other the same as the clamp on kit you would get.  Again, Spikes is known for good stuff, and they chose Adams

So, at the end of the day, I can only give you data on Adams... but it's fairly compelling data to tell you that you can go with a conversion and be very happy.  No idea how PWS is.......  Good luck.

I'll start with this. I've had 6 or 7 different AR's.
With the PWS system, the op rod is tied to the carrier and rides inside a gas piston tube. SUPPOSEDLY preventing carrier tilt.
This is why I went with the PWS/ADDAX system. I don't know of any others that have this.
I work in Aviation so I tend to overanylize everthing and this one seems to calm my OCD.
I don't have enough rounds through mine yet to say anything bad and I am overcritical of any gun that won't function properly.
I did shoot 180 rounds and let it sit for a few months dirty and could not remove the gas piston,
So i decided to shoot a 90 more rounds through it and it has not missed a beat yet.
I did get the piston out of it and looked at it and it appears to be fine.
I refuse to clean it before a 1000 rounds and am looking forward to seeing if it makes it.
90% Wolf steel case ammo through the gun so far..
1 No failures yet
2 With the way the system is set up, very little room for the op rod to flex.
3 They convert or build the uppers
4 I'm hitting clay pigeons at 110 yards, open sights
5 just as smooth as the other AR's if not a small improvement, I think with the PWS muzzle brake.

I have the PWS kit because it doesn't have any springs or anything to wear out. It's worked well so far, just wish they had a low pro gas block, but if that's the biggest problem, I'll survive.

PWS system no issues with LE duty gun.

I think in a technical forum, we have to be very careful when making statements like this.  You say "minimizes bolt tilt to where it is not a prevalent issue compared to other piston systems exhibiting very noticeable bolt tilt."  WOW.  This coudn't be more wrong, and statements like this can give a noob asking a question the wrong impression.  This gross generalization is WRONG.

There are many owners of piston guns out there right now that shoot the crap out of them and are not seeing carrier tilt wear.  I have an LMT carbine retrofitted with an Adams Arms piston kit, and it shows NO WEAR so far.  I have a Ruger piston gun that IS showing signs of carrier tilt.  So some guns do and some don't.  PWS is NOT the only piston kit or piston gun around that works with no carrier tilt.

His statement "compared to other piston systems exhibiting very noticeable bolt tilt" does not in any way imply all or a lot of other piston systems are having this issue.  What it does state (in plain English) is a comparison between the PWS system and "other piston systems [which exhibit] very noticeable bolt tilt."  If he had said "all other..." then you'd have a valid point.  But he didn't.

I have a PWS piston gun that shoots MOA.  You will be happy if you order the PWS.

My big problem with kits is that every manufacturers equipment and specs may react differently with other manufacturers piston conversion kits.  almost all of the problems that I have heard surrounding carrier tilt and reliability issues with PG's are kits, not manufactured GP guns.  So as a result, I have bought two piston guns (and have two DI guns).  

I have not had any problems out of my PWS Diablo and I have had it for around 800 rounds now both select fire and SA.  I did have one FTE, but just 1.  I really like the long stroke piston system and that it attaches to the BC instead of floats in a spring above the barrel.  I have no carrier tilt what so ever.

I have yet to receive my LMT CQB MRP (i ordered November 7th).  I am anxiously awaiting its arrival and according to LMT it is at the top of the list to ship.  I hope to have it within the next two weeks.  I have heard no one have significant reliability issues related to flawed design past the first 100 rifles manufactured so I can't imagine why mine would be the first.  

I know kits are much cheaper than new guns but when I bought my two GP rifles I saw it as like playing Russian Roulette with buying a kit.  You never knew which kit would work or not because all kits seemed to have both, people that cursed them for problems and people that praised them for performance.

Your post demonstrates that this particular PWS system had no tilt.  I did NOT say, in response to your post,  "PWS systems do have tilt".  I suggested that you inferred other systems all have tilt, and I said this is not true.

Then a bunch of people jumped my shit, saying you did not really say that, but here, in your reply you say

"only that with the PWS Piston System the amount of noticeable bolt tilt is minimal compared to other piston systems."

So you just said it AGAIN, and now directly said what you inferred in your first post.

You do not have any body of evidence to suggest PWS systems have tilt that is "minimal compared to other piston systems", so you just should NOT say it.  You should say "PWS systems do not demonstrate noticeable tilt".... and then stop.

WORDS MATTER.  Especially when conveying information to somebody who is trying to learn.

Just got a Adams Arms upper, 1,000 rds in 4 days thru it so far no issues. They have a pretty neat bolt carrier and spring around the bolt to prevent the buffer tube wear you see with other piston systems.

My Adams kit with original carrier where I replace the gas key with their key also has no tilt wear signs.  I just got a new Adams carrier and I will be testing that out.

That's my only point... I am not dissing PWS.... I have never seen a PWS kit...... all I am saying is that PWS is not the only kit / rifle that does not display tilt, so say PWS is "better" than other kits because it show less wear is just plain wrong.

Did you get carbine length or middy length kit?

Can the PWS gas system be adjusted?  In the shot above, the brass is ejecting 45 degrees FORWARD, the sign of an overgassed system.  How do you adjust the system?

Picture of the back of the BCG from my Spikes Tactical/Adams Arms piston gun. note it's oversized in the rear AND nicely bevelled to prevent damage to your Buffer-tube

Ya, that's what my new carrier looks like.  REALLY nicely machined piece of work.....

I've seen the "self adjusting" term used with a few systems.  It does not make sense to me.  If you have a really hot round, then the pressure in the barrel is much higher, and the force imparted to the rod will be much higher, so the force imparted to the carrier is higher.  What feature of the design is "self adjusting".  Where I've seen it used incorrectly is where designers say "after the system moves the predetermined amount to move the carrier the gas is vented"...... yes, these types of systems are self regulating with respect to LENGTH OF MOVEMENT, but they cannot regulate the FORCE of the movement.  It's the force and power in the movement imparted to the carrier that moves it back and dictates how the brass is ejected.

So, why is the brass ejecting forward, and how does the PWS system regulate the STRENGTH of the pulse imparted to the carrier vs. how far the carrier moves?  Even LWRC, which always claimed to have a self regulated system now puts a regulator on their new M6A3.   That's because the system was self regulating for length of movement but not force in the movements impulse.

Interesting..... any animations of the system around?  I would like to see how the long stroke occurs.... or at least some sort of detailed drawing of the differnet phases of rod movement?

Maybe I can snag something on YouTube...

So, are PWS systems sold as complete uppers?  or do you buy the system and have it retrofited to an upper?

I see from your site that PWS appears to have short stroke and long stroke systems..... rather, the uppers you sell have both types?

if I go to the PWS site, I only see them sellng on kit.

Anyway.... how much is it for you to install a kit on my BCM middy upper.... about..... I figure you can't be exact....