Quoted: WITH THE PWS PISTON SYSTEM IN THE SUPPRESSED GAS POSITION, BUT WITH THE WEAPON UNSUPPRESSED, IT  ALSO RAN 100% RELIABLY WITH XM193 AND M855, BUT SLOWER THAN I EVER WOULD HAVE IMAGINED POSSIBLE:

Hey Todd, I thought the idea was to size the gas port so it would NOT function in the restricted setting WITHOUT a suppressor?  It would seem to me the gas port is too big if its functioning  in the restricted setting without a suppressor.  On the barrels I've installed the system I kept things to a minimum without any loss of function.

Quoted: In case anyone is wondering - on the minus position (selected in the second half of the video) the rifle typically will not cycle, as the amount of gas that is let into the chamber is restricted to compensate for the increased pressure created by attached a suppressor. Todd

Quoted: Quoted: WITH THE PWS PISTON SYSTEM IN THE SUPPRESSED GAS POSITION, BUT WITH THE WEAPON UNSUPPRESSED, IT  ALSO RAN 100% RELIABLY WITH XM193 AND M855, BUT SLOWER THAN I EVER WOULD HAVE IMAGINED POSSIBLE: Hey Todd, I thought the idea was to size the gas port so it would NOT function in the restricted setting WITHOUT a suppressor?  It would seem to me the gas port is too big if its functioning  in the restricted setting without a suppressor.  On the barrels I've installed the system I kept things to a minimum without any loss of function.

Ambient temperature was around 95 F, drop that by 30 degrees and I would expect to see  a lot of short stroking. Also, this gun was running a YM full-auto carrier with all DiamondBlack coated internals. These components run far easier than standard phosphated ones, which I doubt you could get to run reliably at 500 rpm. This particular upper receiver was converted to piston while Wes was in Idaho at PWS. Dean and Wes set it up with the ammunition available at PWS, and to their spec. Nothing they had ran in the suppressed mode. Obviously, a change to full power ammo and hotter temps plays a role. The more important observations would be how well the system ran over a wide range of inputs, some of which would not begin to run reliably in a typical AR setup.

Quoted: Hey Todd, I thought the idea was to size the gas port so it would NOT function in the restricted setting WITHOUT a suppressor?  It would seem to me the gas port is too big if its functioning  in the restricted setting without a suppressor.  On the barrels I've installed the system I kept things to a minimum without any loss of function.

Yes - in most cases the system will not run with the reduced port size of the "minus" setting.  However, this also becomes very ammo dependant as well as barrel quality, etc.

The rifle I just used for the MGM Ironman this weekend would not function with Wolf on the minus setting but would using the PMC that we used for the match.  This is also a quality barrel, tighter tolerances, etc.

The "not running" was mentioned as you posted a video of our system short stroking without an explanation of why - so I thought this would help clear up any questions.

Hope this helps.

Todd

Quoted: Quoted: Hey Todd, I thought the idea was to size the gas port so it would NOT function in the restricted setting WITHOUT a suppressor?  It would seem to me the gas port is too big if its functioning  in the restricted setting without a suppressor.  On the barrels I've installed the system I kept things to a minimum without any loss of function. Yes - in most cases the system will not run with the reduced port size of the "minus" setting.  However, this also becomes very ammo dependant as well as barrel quality, etc. The rifle I just used for the MGM Ironman this weekend would not function with Wolf on the minus setting but would using the PMC that we used for the match.  This is also a quality barrel, tighter tolerances, etc. The "not running" was mentioned as you posted a video of our system short stroking without an explanation of why - so I thought this would help clear up any questions. Hope this helps. Todd

Gotcha. In all my playing I was concerned with making it work the best as it was designed, not how to make it work as is wasnt designed to work.  With the good SS barrels I used, we played with different gas ports and ammo. We got it running like a watch, with a tiny gas port for all ammo in the "O", and so it only works with a suppressor with the "-" setting.   That way it takes full advantage of the features as they were designed without having to swap around other internal parts.

Sorry about the video - it was misleading unless it was watched in the context of the thread it was in. I deleted it a couple weeks ago.

THAT'S NOT THE ONLY THING IN THIS THREAD THAT IS MISLEADING.

PIX OF ONE OF OUR PWS 10.5" UPPERS WE'VE BEEN RUNNING:







WES GRANT
MSTN.BIZ

WHAT SORT OF COMPONENTS DID YOU USE IN YOUR PWS PISTON SYSTEM BUILD? PIX, MAYBE?

I WOULD GUESS THAT THEY WOULD HAVE TO BE TOP SHELF, BECAUSE 5,000 RD OF QUESTIONABLE AMMO WITH NO CLEANING OR LUBE IS QUITE A CHALLENGE.

GOOD SHOOTING,

WES

i took mine apart today for its first cleaning, its one of the first ones, i had thought about selling it as Todd has a special project going on for me, but i can't part with it.   of course now i need to figure out what way the knob should point.....

its had about 1300rds without cleaning and was dry as a bone when i took it apart, but it came apart easy and looks good.  

I normally keep dealings between us and other industry individuals from the public’s eye – but I have received a shit ton of emails and phone calls about this – so I thought I would get it out there for clarification.

Bigbore sent in an upper to have the system installed on it.  Once it was returned to them, it was removed and re-installed on a different upper without any documentation or tooling.  One set screw was pushed against the barrel (not dimpled) and one taper pin was used to hold the system on and the gas block was not in the correct position.  I even got a phone call from a customer that saw the install at their shop and wanted to know how we could stake the screws when the screw protruded so far out from the gas block.

The result was that the operating rod was too far from the piston when in battery so the piston had a hefty run before impacting the operating rod.  This absolutely will result in a train wreck – which is what causes things to break.  

We were then contacted to get some replacement parts, at which point we wanted to get the upper in our shop to attempt to fix the install.  This is why we were very hesitant to send out replacement parts without seeing the installation.  After a few days, we were obviously able to work it out and clarify the important aspects of the install to ensure a properly running system.  

Anyway – this is not an attempt to badmouth Steve and the gang – I just wanted to get the facts out there as many feel the issues have been a result of a poorly designed system and that is not the case.

Hope this helps.

Todd

Quoted: The result was that the operating rod was too far from the piston when in battery so the piston had a hefty run before impacting the operating rod.  This absolutely will result in a train wreck – which is what causes things to break.

WTF are you talking about? The OP Rod was the perfect distance from the piston, the problem was your weak SS piston. After you sent me a hardened piston things ran great, and have run fine ever since. If it was installed wrong, it would not be working today. There was nothing wrong with my install.


per your email:

Sorry for the delay – we’ve been testing and abusing today to see what is happening. It seems we have kind of stepped on it, as we had done most/all of our full auto testing using a hardened piston.  We then switched to the stainless steel piston and did some more testing - even quite a bit in full auto.  (we had switched to the stainless because “bubba” was worried about corrosion – and we listened… and then we stepped on it… ) We are now noticing an issue that oddly enough is not present in 14 and 16" barrels but is almost instantly noticeable in the 10" and 11.5" barrels, which is the piston is swelling and causing stoppages.  The odd thing is that we have done HORRIBLE things on a 16” barreled unit in testing and never had any issues at all.  In one of the water submersion tests (dunk the rifle in water, pull out, insert mag, dump mag, repeat) we bulged a barrel and blew up a suppressor – but nothing happened to the piston.  In fact, after swapping the barrel on the upper, 3 people SHARED it this past weekend in a tactical match running a little over 800 rounds through it throughout the day with no so much as a short stroke.  (this is all with a stainless steel piston that was run off of the same barstock as the one you have)  I would like to say this is caused from the larger port in the barrel – but on the test guns (where we try to break the piston system) we have larger gas holes to purposefully overpressure them… ? At the end of the day, we really have no idea why it would be so much more horrible on the uber short guns, but it is  - so… we are going back to the heat treated S7 piston, which is the same material that we use on the carrier key and shear pin. (I know you love that stuff) So - they are turning out now, but it sounds like heat treat is going to hold us up a couple days - actually several days, as we will have the pistons back on Tuesday. As soon as I get those, I will send you a new carrier key and op rod, piston tube and piston and let you go back to your testing. J If… by some chance when this is all taken care of… you want to become an installer, we can run the blocks with no holes in the bottom of the block so you can install them with taper pins. Let me know your thoughts and we’ll go from there. Todd Tuttle Primary Weapons Systems www.primaryweapons.com (208) 344-5217

Did you get the name of whover call you when they saw it at my shop? They must have called you because I told them it was non of their business what the issues until I figured them out with PWS.

Im the one who actually installed this POS, and trust me ive installed thousands of Gas blocks and FSBs and other devices over the years i think i have a little experience, as to where dimples, and or pins go. If your piston was made of hardened tool steel like it should have been in the first place, there would have been no problems, but you decided to side with the e-commandos, and go for corrosion resistence instead of functionality. Try again

The installation and the email regarding the piston were two different issues - but as you feel you must blend them together so that your story sounds better, then I suppose you must.

I thought I made it clear that I was not trying to bad mouth you guys - but rather fill in some blanks for those who had questions.  Nonetheless - I'm done with you guys and I invite you to send the parts back for a refund if you are unsatisfied with the system.

Todd

Quoted: Long story short....there is no need to spend the extra money on a piston system....no matter who you are, DI guns work just fine. Pistons are the new flavor of the month...an by the way...it doesn't taste too good. Nothing more than hype and internet marketing to people who don't know any better than to buy what they think/told what is cool. This isn't a rant about the PWS piston, though I saw it break more than once, I am against all pistion systems...HK...whatever. Show me a real need for sweeping change and I will become a believer, but as of yet I don't see one good reason in sight to ditch the DI system. Now a piston for an SBR? Maybe...but even then, I know of a lot of 10.5 DI Colts that have worked just fine and have been ran pretty hard for the last seven years in some pretty extreme places.

YOU SAW WHAT SPECIFIC "IT" BREAK MORE THAN ONCE, THE ADCO ONE?

OR ONE ASSEMBLED BY SOMEONE ELSE?

WES

YOU SAW WHAT SPECIFIC "IT" BREAK MORE THAN ONCE, THE ADCO ONE?

OR ONE ASSEMBLED BY SOMEONE ELSE?

WES

Quoted: I have been running the PWS for about six months..... ... Total approximately 5000 rounds so far...WITHOUT CLEANING or LUBE. the system ran flawlessly!!!!!!!

Apparently rusting shut after a week is not an actual issue.  So it seems we can all go back to being civilized.

Todd

A soft SS piston that works fine on an un suppressed 16" carbine is one thing.  If you paid attention to this thread you'll see your system behaves differently on different platforms. When someone else puts the system on a 11" barrel, with the tool steel piston, then runs a few hundred rounds of wolf, with a suppressor and lets it sit for a week, it will rust.  Wolf has a way of making everything a wet mucky mess through a suppressor which gets blown into al the parts of the kit.  Perhaps harchroming the piston is the answer, but what do I know.....

When I said "we could all be more civilized now..." it was not directed at anyone - it was directed at everyone - myself included.  

The SS piston was an issue - yes.

The SS piston was not used during development and was a last minute change on our part (stupid - but we did it).

Once we found the issue (and Steve was one that pointed it out) we resolved it - problem solved.  No more issue.

The unpleasantness started (from my end) because I was getting numerous calls and emails regarding unexplained issues noted in this thread.  I was attempting to add clarity, but obviously failed as I incited no less than a riot.

There is much too much drama on AR15.com and I am embarrassed as an industry partner to add to it.  I was completely serious when I said that my statements were not an attempt to badmouth Steve and the gang.  However, be it he volatile nature of ARFCOM or simply my communicative failure, my statements were not taken as such.

To this end - and hopefully as an end to this drama, the issue with the piston was resolved, replacement pistons sent out and the product remains a well built and functional item.

As far as the rusting issue goes - we have not seen this at all.  We have been working on this system for 2 years and in such time ran several thousand rounds of Wolf through a rifle with the same type of piston.  We then put the rifle on the shelf and let it sit for nearly 4 months.  Took it back out one cold winter day to see if it would shoot and it did - without issue, short stroke and any other sort of failure.

This is not to say that you could not make it rust.  To say that would be asinine.  If you leave your anodized aluminum lower wet and stored - it will rust - that is how rust works.  However, from everything we have seen, the temperatures created in the barrel and gas block will not allow moisture to accumulate, but rather evaporate.

Finally - the idea that our system resulted from us jumping on the bandwagon of a fad couldn't be further from the truth.  Many of you may remember that we were AK guys - and while developing and testing a muzzle break for the AR, were shocked and appalled at the failures seen in the ARs compared to the AK.  We did not simply make a copy of something that was already out there, but rather stepped back asking "why does it have to be that way".  We also wanted to make sure it was something that could be compatible with as many hand guards/upper combos as possible.

In short - we didn't build this system to jump on a fad - we built it because we saw a need.  And yes, as Steve said, if you don't think you need it, then you don't need it.  Same goes with our comps.  Those who have them think they are great and we sell a ton of them - not because they are the new fad, but because they work.

Hopefully this clears everything up and everyone can be friends again.

Todd

Last weekend Dean and I shot our first 3-Gun Match - which was the MGM Ironman.  (nothing like a little baptism by fire!)

Anyway - we obviously built up a couple rifles using our piston system and here are a couple pictures of my rifle and system after the shoot.

Dean's optic failed on the second day (or perhaps it was him? ) nonetheless he was no longer hitting what he was aiming at - so on day 2, he started using my rifle as well.  We also had another squad member who's rifle went down and he also used my rifle for 2 of the 3 days.  The rifle functioned flawlessly through an estimated 1100 rounds over the 3 days.  

For anyone that has ever shot the Ironman - the dust out there is insane - a strange mixture of baby powder and concrete like dust that simply gets everywhere.  You can see an example of it on the last picture of the Magpul mag.



I used the Leupold 1.5-5x20 MR/T on a LaRue SPR Mount - an unbeatable combo in my opinion.  I normally left the MR/T on 5x and used the JPoint Red Dot on a Matt Burkett Offset JPoint Mount for the close stuff.  




Here is another angle to show the MB mount in relation to the LaRue mount - a great combo together.




Here is the system disassembled - the thing that I found very interesting (exciting) was that after 3 days in the crap and shooting a fair amount of ammo - the bolt carrier group was still wet from the lube I had put on it the day before the match.  Typically I do not run any lube at all - but thought as this was an actual competition - I should lube up a bit.  As we say around the shop - "There's always time for Lube!"




Here you see the piston parts - which oddly enough still look like this.  After I took these pictures, I put the rifle back together and went shooting again.  Not sure if/when I'll actually clean it.  It was nice to actually get some dust and scratches on my rifle.




The Bolt Carrier Group after the match.  This really illustrates the differences between a piston driven system and a DI gun.  The heat stays up front and not back in your action where it is more likely to cause problems.




Again - the bolt still very lubed and clean.




Here you can see the typical wear we see regarding carrier tilt with our system.

Overall - very pleased with the accuracy and reliability with the system.  We did not clean the rifle, brush the barrel/chamber or anything in the way of cleaning and were very happy with the results.


A side plug for a couple products I can't say enough good things about.  The Timney 3lb Skelotonized Trigger is, for me, the perfect trigger.  If you like 2 stage triggers - you'll probably hate it.  If you like a single stage - I think this would be very tough to beat.

The other is the Magpul P-Mag.  Not only did we not clean our rifles - but we did not clean our mags and they ran flawlessly even in that horrific dust!  The picture below is where I dropped one of my mags during a stage.  One of the ROs saw me pick it up and said, "you better clean that..."  I thought about it - then decided to just push the follower down with my fingers and blow the mag out a little and reload it.  It did not let me down and functioned flawlessly on the next stage!




Special Thanks go out to Mike and the gang at MGM Targets for putting on the Ironman - if you haven't been, it is really a must see!


Todd

Yes!

(I wasn't 100% sure - so I threw one together this morning and it actually fits great!)

Todd

MSTN is probably the closest installer to you.

MSTN Piston Thread

MSTN Website

Todd

The PRI is not "needed" but they are a very nice charging handle.  No flex, very strong, very comfortable.  

I personally like them because I can grab it on the side with my weak hand and operate it without any flex or drag.

Really it all just comes down to personal preference...

Todd

GOOD POINT.

WES

Quoted: 1.  How does the PWS compare to the ARES?

See Below -

2.  Why use the long Op rod attached to the bolt carrier key?  POF, LWRC, HK, Ares used a separate op rod.

Coming from the AK background - we looked around at other platforms that were piston driven.  Some (such as the AK) used a rod that was the piston, but also attached to the carrier.  Others used an op rod and a separate piston.  In a perfect world, the op rod and piston would be one - but we didn't have enough room for the consistent outside diameter of a one piece, so we elected to have the piston separate and the op rod attached.

Looking at the carrier tilt issue, we decided that attaching the op rod to the carrier and having the force between the piston and the op rod be forward and contained - we could eliminate much of this issue.  The result was also a very smooth recoiling system - not as punchy as you might find others to be.

Hope this helps.

Todd

Here are a couple shots of our latest project.  In cooperation with JP Rifles, we are working on some modifications to the Viking Tactical forearm that allow it to work with our system.  











The modification is similar to that of Henderson Defense with the YHM rails.

Todd

The modification needed to get it to fit under the Viking rail was to stand the tube on end, run an end mill down opening the tube relieving the top of the tube approximately 60 thousandths.  We went down about 2.5" - then simply milled the top of the tube out in the middle so that we could get the tube to clear the inside.  The rail being screwed to the top of the tube covers the hole - so in this application it worked.  

As far as the PRI carbon tube goes - it is difficult to tell without just starting to cut - which I do NOT want to do.

I know that isn't much of an answer - but I didn't want to just ignore the question.

Todd