AR Piston Systems Choices

[Gutshot John]

I apologize in advance as this has been probably covered ad nauseum.

I've done a few searches on "AR AND PISTON" and have found some good information, but it's still pretty confusing.

Currently I have a Stag that I modified to suit my taste and while I like it, I've wanted a higher end AR anyway so I thought I might replace the upper with a piston system or buy a new piston AR altogether and have two.

My first priority is durability/reliability. The whole point of the piston is to increase these qualities, so any piston that is questionable relevant to DI systems is not an option. I have enough basic gunsmithing knowledge to keep one running for a while with available parts, so parts interchangability/availability is my second most important consideration. A trade-off between long-term reliability and parts availability is acceptable. In other words I'd consider a rifle I can fix easily/readily than a rifle that is more reliable, but once broken is unfixable.

In my research I've found the following to be "generally" true though some might quibble.

First the 416 seems to be the highest quality option out there (and probably my favorite) though I'm not sure I want to spend $3K once it becomes available. An upper swap might be an option though if it's as expensive as a comparable rifle then I don't know if I want to go there either. Given the expense/availability of parts, the trade-off in net reliability would have to be substantial. That being said, if it's really that good... then that money doesn't seem so much.

Second there is the LMT MRP(PWS) and LWRC uppers/conversions in terms of serious use. I understand little about the LMT, and while the LWRC has its following, there are reports of problems. This being said it seems to have the most part interchangability. These options also seem quite a bit more reasonable in terms of cost. I'm not sure whether it makes sense to buy a whole rifle or just swap uppers/do a conversion.

Third, I've heard a mixed bag relative to the POF uppers though DSA seems to be marketing them at relatively reasonable prices. I know little about the Bushmaster conversion, but it seems to be the least expensive option. The question remains if it's cost effective. If it qualitatively improves the reliability of my Stag that might make sense too.

Is my understanding of the above flawed? Likewise are there options I'm not considering that I should?

[jhs1969]

I am looking forward to going to a piston system as well but after looking at all the AR designs I came up with a different game plan. My problem with AR piston systems is that they were not designed as one. I heard and seen pics of accelerated wear. The carrier wasn't engineered to be 'hit' off center, the wear I've seen has been from the carrier going into the ext. tube after this off center hit.

My plan is to get an original piston design. I'm waiting to see the release and performance of the Massada/BM ACR and the FN SCAR then there is the standby SIG 556. I will keep my two M4's and add one of these in time. There are other systems I wish were available (G36, TAR21) but the ACR and SCAR seem to hold a lot of promise. Just my $.02

[Gutshot John]

Actually the thought of whether the AR was designed for a piston was something I considered and why I was shying away at least from the conversions.

Those other rifles had appeal, but I'm not as confident in an ability to scrounge parts for them. One of the things that appealed to me about some of the AR piston systems was that there was 60%+ parts interchangeability with the standard AR.

Any comments from the peanut gallery as to accelerated wear? Anyone in the know?

[cd228]

Colt displayed a piston rifle at the 2006 landwarrior exhibit at Fort Benning. The rep called it a M5. Is any one tracking it. It was beatiful rifle.

[Gutshot John]

I've only seen it online. Though I don't know what their intended market is. It looks like a neat design. If they offer it to civilians that might be the good option.

[OldNavyGuy]

just recently i got some inside info on a new AR piston system about to hit the market, it is in my OPINION, the most advanced system yet, i believe it will put the "416", POF, LWRC systems in the "acceptable" bracket, i have been promised an upper for testing and evaluating within the next 4-6 weeks..., hang in there and when i get this upper and put a thousand rnds. or so thru it, i'll write up a report, exclusive to "The Firing Line" forums.

[variablebinary]

I like the LWRC system a lot. Every LWRC gun I've encountered has been a tank, but since it takes them 4-5 months to ship product, I dont have heaps of faith in LWRC as an organization. Something somewhere is busted in their internal people, process, technology or money which leads to horrid order fullfilment times

I look forward to the LMT piston as well. LMT makes good stuff and their management is solid

In the absence of the HK416 I am passing on the piston revolution...for now.

I dont have any interest in POF, or PWS and Ares conversions

[Shihan]

just recently i got some inside info on a new AR piston system about to hit the market, it is in my OPINION, the most advanced system yet, i believe it will put the "416", POF, LWRC systems in the "acceptable" bracket, i have been promised an upper for testing and evaluating within the next 4-6 weeks..., hang in there and when i get this upper and put a thousand rnds. or so thru it, i'll write up a report, exclusive to "The Firing Line" forums.

This kind of stuff is better to post when you have some info to actually share.

[SMGLee]

Have you taken a look into the Primary Weapon system piston conversion? It is very robust and the price and turn around is good, I would said it is on par with the LWRC and it may surpass it because it is more user friendly with a front draw piston that you do not need to remove the top rail to get to the assembly. this is a lot like the LMT or the POF desing, but unlike the LMT, it is not mate to a ultra expensive MRP and unlike the POF, it is low profile enough that you don't need to use a rail on rail application to accommendate the piston assembly.

I will get some pictures on line for your viewing enjoyment this evening.

[Firecop203]

Bushmaster is now advertising a conversion to the new gas system in their catalog, priced at $400.00.

[variablebinary]

Bushmaster is now advertising a conversion to the new gas system in their catalog, priced at $400.00.

Isnt the Bushy conversion just a licensed Ares?

[Robb Jensen]

Isnt the Bushy conversion just a licensed Ares?

Yes, that's all it is.

[Seth Harness]

This kind of stuff is better to post when you have some info to actually share.

Agreed.

[Tspeis]

just recently i got some inside info on a new AR piston system about to hit the market, it is in my OPINION, the most advanced system yet, i believe it will put the "416", POF, LWRC systems in the "acceptable" bracket, i have been promised an upper for testing and evaluating within the next 4-6 weeks..., hang in there and when i get this upper and put a thousand rnds. or so thru it, i'll write up a report, exclusive to "The Firing Line" forums.

Just curious who will be releasing this new system? Why do you feel it's superior to all the other systems currently available? Especially when many of them are already proven designs.


Tspeis

[SHIVAN]

Actually, let's not play "internet rumor" games. If the piston upper in question is ready to come to market, then discuss it -- openly. If it's still a secret, keep it that way.

We're not going to allow much more latitude for rumors and games.

Thanks.

[ARin]

ive kinda been discounting the ARES/BM and the osprey systems due to the gasblock roll pin issue. A roll pin makes little sense to me as a stress bearing point. And that has been backed up by some reports of roll pin failure.

it would seem that systems that use their own gas block make a lot more sense in terms of design stoutness.

the PWS system costs the same as the ARES/BM and appears to be a more well thought-out design.

[Tspeis]

ive kinda been discounting the ARES/BM and the osprey systems due to the gasblock roll pin issue. A roll pin makes little sense to me as a stress bearing point. And that has been backed up by some reports of roll pin failure.

it would seem that systems that use their own gas block make a lot more sense in terms of design stoutness.

the PWS system costs the same as the ARES/BM and appears to be a more well thought-out design.

For what it's worth, the HK416's gasblock is held in place on the barrel by two roll pins. I've never heard of it being an issue, but then again, you are describing two completely different systems.


Tspeis

[ARin]

HK doesnt even rate with me when looking at gas systems. they are not yet civvie available (officially) and they cost a billion dollars. couple that with HK's general attitude toward civvie sales.....and like i said, they dont rate.

[Resq47]

I'm cautiously curious about the PWS conversion and think it's a digestible amount of money to plunk down on something that needs proprietary support down the road. Actually, their conversion might be compelling in a VIS upper.

Must not think expensive thoughts...

[Packman73]

I like the LWRC system a lot. Every LWRC gun I've encountered has been a tank, but since it takes them 4-5 months to ship product, I dont have heaps of faith in LWRC as an organization. Something somewhere is busted in their internal people, process, technology or money which leads to horrid order fullfilment times


It took 4 months for mine. Worth the wait imo. And great customer service from all I've read.

[CarlosDJackal]

I like the LWRC system a lot. Every LWRC gun I've encountered has been a tank, but since it takes them 4-5 months to ship product, I dont have heaps of faith in LWRC as an organization. Something somewhere is busted in their internal people, process, technology or money which leads to horrid order fullfilment times...

This is the same reason I held off in buying one - until I found a shop in GA who had the exact model I wanted (10.5-inch M6A1). I had the upper 3 days after I found out they had one (due to shipping and a delay in my committing to buying it). After almost 1,000 rounds through the gun, most of which suppressed, I have only had 2 malfunctions.

The first is a failure to feed with the very first magazine I ran through it - this was operator error. In my excitement to shoot the upper, I forgot to lube up the BCG. :p The second malfunction was also a failure to feed and happened with an old aluminum magazine I have had for more than a decade. This magazine has been through at least 4 Carbine Courses and is due for an upgrade (although I might keep using it at the range in order to induce malfunctions for IADs). I have been extremely happy with my LWRC upper and am planning on using it at the Larry Vickers class I will be attending in South Hill, VA in July as well as the Pat Rogers class I am planning on attending in PA in August.

LWRC's delivery delays are currently being addressed with their "partnership" (NOTE: I'm not sure if that is the correct term) with Matec. Once they establish their production line in their new facility (not sure where it is), they hope to catch up to their backlogs. We'll just have to wait and see if they do. However, I cannot say enough good things about the guys at LWRC. Not only are they very innovative, they also provide excellent customer service. They will answer any question that you may have in a timely manner. YMMV.

[variablebinary]

LWRC's delivery delays are currently being addressed with their "partnership" (NOTE: I'm not sure if that is the correct term) with Matec. Once they establish their production line in their new facility (not sure where it is), they hope to catch up to their backlogs. We'll just have to wait and see if they do. However, I cannot say enough good things about the guys at LWRC. Not only are they very innovative, they also provide excellent customer service. They will answer any question that you may have in a timely manner. YMMV.


I hope LWRC gets their act together. They have a solid product that is way above average in terms of AR15 piston designs.

At one point I wanted nothing to do with LWRC. Everyone here knows the history I am sure, but the product won me over.

However, there are still some shenanigans and mismanagement in place which keeps me from supporting them.

I'm hoping Matech sorts them out. Their CHF barrels and single piece carriers in the works shows they are committed to building a better product. If only they can fix the company now before HK comes out to play, because as solid as LWRC carbines are, I'd rather own HK

[Gutshot John]

It took 4 months for mine. Worth the wait imo. And great customer service from all I've read.


4 months isn't bad. I think I waited at least that for my DSA.

Does anyone know what the parts' interchangeability percentage between the HK Piston system and the DI AR?

[caporider]

ive kinda been discounting the ARES/BM and the osprey systems due to the gasblock roll pin issue. A roll pin makes little sense to me as a stress bearing point. And that has been backed up by some reports of roll pin failure.

it would seem that systems that use their own gas block make a lot more sense in terms of design stoutness.

the PWS system costs the same as the ARES/BM and appears to be a more well thought-out design.

I have the Ares kit on a 12.5" SBR. It is mounted to a standard taper pinned FSB with the correct handguard cap in place. Over the course of 300 rounds, the roll pin holding the system to the FSB has not moved, bent, or sheared.

The Ares kit is designed to work with the handguard cap; omitting this vital component leaves a gap between the piston housing and the FSB. This gap, in turn, forces the roll pin to bear all the stress of the system in operation. Given this type of setup, it is inevitable that the roll pin will fail. With the handguard cap (or equivalent thickness of metal) in place, the roll pin is relieved of having to bear all the stress of the piston and op rod slamming back into place. Based on the accounts I've read of Ares kit owners, I'm willing to bet many if not all the roll pin failures occur on rifles that don't have a handguard cap or equivalent thickness of metal in place.

I am, however, concerned about the accelerated wear on two components: the buffer tube, and the cam pin. The buffer tube shows wear marks which are the direct result of carrier tilt. I'll have to see if the wear marks stabilize over time, or if they get worse. The cam pin has had most of the finish worn off after 300 rounds, and I believe this is the direct result of two things: the cam pin hole in the bolt carrier having a sharp corner (sharper than the other DI carriers I have), and the bolt not having gas rings to buffer its movement in the carrier. I will watch both items to see if wearing gets worse over time.

Recoil on the Ares-modified SBR is definitely sharper than any DI 5.56 I've shot; it's pretty close to what I feel shooting my 6.8. Still, nothing to be worried about. The Ares system does greatly reduce blowback when I shoot my SBR suppressed, and that alone is worth my continued testing of the system. If, ultimately, I decide the Ares is a no-go, it is a simple matter to convert my SBR back to DI operation.

[OldNavyGuy]

This kind of stuff is better to post when you have some info to actually share.

no problem friend, just wanted to give a heads up advance notice to those who want to jump at the first thing available on the shelf.., i'll keep all further info to my self till i am ready to post.

thank you for the "heads up" :cool:

[davechng]

I've got my POF USA upper and it worked 100% no issue ! Have RDIAS and it ran with no issue also! it will chew in wolf, Radway green SS109, Q3131... etc

I am using the POF-upper with BUshmaster lower and Ace SOCOM stock! WIlson Tactical BUIS and EOtech 552

I like the POF system is that you can change the gas system from supress to normal.. I have tried it in 2 supressor and it worked great!

the piston takes apart easier than others ! don;t need to remove the handguard or anything!

http://i3.photobucket.com/albums/y66/davechng/Guns/P1010149.jpg

My 2 cents!

DaveC

[OldNavyGuy]

Just curious who will be releasing this new system? Why do you feel it's superior to all the other systems currently available? Especially when many of them are already proven designs.


Tspeis

""Why do you feel...""

my friend, i am NOT a liberal, therefore i do NOT "FEEL".., i BELIEVE and i THINK :D

[TUNNEL RAT 33]

I too have a POF 16 inch . what i really like about it is the ease of cleaning . due to the coating and lube everything wipes off . i dont have the new barrel but the cleaning process is the same as a regular m4 . my rifle did take 6 months though to reach me . that being said i recently bought aLM
T MRP in anticipation of the LMT piston .http://i277.photobucket.com/albums/kk76/tunnelrat33/th_DSC00007.jpg (http://i277.photobucket.com/albums/kk76/tunnelrat33/DSC00007.jpg)
http://i277.photobucket.com/albums/kk76/tunnelrat33/th_DSC00018.jpg (http://i277.photobucket.com/albums/kk76/tunnelrat33/DSC00018.jpg)

[caporider]

Quick update on the Ares kit...

I have another 150 rounds through this SBR. I have resolved the short stroking issue: it was the DD Omega rail. It had not been clearanced enough by the vendor so the piston was dragging along the inside of the rail. The vendor is now going to clearance the Omega rails a bit more to ensure piston drag does not occur.

Accuracy testing at 100 yards revealed this SBR to hold a reliable 2-3 MOA shooting PMC .223 ammo and 1-1.5 MOA shooting Hornady 75gr TAP .223. For what I intend this SBR to do, this level of accuracy is just fine.

Overall, I am cautiously optimistic about the Ares kit on this SBR. I have 1500 more rounds of PMC to burn through before I declare the Ares kit suitable for classes, home defense, etc.

On to the pics.

The SBR.
http://www.visuality.com/personal/556/556_ares_1000.jpg

The SBR with Surefire can attached.
http://www.visuality.com/personal/556/556_ares_can_1000.jpg

The Ares kit installed showing the DD Omega rail before additional clearancing (note drag marks).
http://www.visuality.com/personal/556/ares_dd01_1000.jpg

The DD Omega rail after additional clearancing.
http://www.visuality.com/personal/556/ares_dd02_1000.jpg

The piston system butted tight up against the handguard cap - the roll pin has not moved so far.
http://www.visuality.com/personal/556/ares_fsb_1000.jpg

Non-standard wear patterns on buffer tube due to carrier tilt.
http://www.visuality.com/personal/556/ares_buffertube_1000.jpg

The firing pin, cam pin, and bolt after shooting 50 rounds suppressed -- not bad! Note the wear patterns on the cam pin. BCM bolt, Colt cam pin.
http://www.visuality.com/personal/556/ares_parts_1000.jpg

[ARin]

why not leave an OLD set of gas rings in place on the bolt to steady its movement inside the carrier? i cant see the small amount of drag added by the rings being any issue. but i CAN see it stabilizing the bolt and reliving any wear hotspots.

[caporider]

why not leave an OLD set of gas rings in place on the bolt to steady its movement inside the carrier? i cant see the small amount of drag added by the rings being any issue. but i CAN see it stabilizing the bolt and reliving any wear hotspots.

With the Ares kit, you get a new, purpose-built carrier with an integral "key" for the op rod to push against. The carrier will not let you insert the bolt with the gas rings installed. Ask me how I know...

[Seth Harness]

Good pics. Keep a real close eye on the G/tube roll pin, Just a word of advise.

Hey!! I can fix that carrier tilt issue! :D

[ARin]

With the Ares kit, you get a new, purpose-built carrier with an integral "key" for the op rod to push against. The carrier will not let you insert the bolt with the gas rings installed. Ask me how I know...

gotcha! i knew that the ares came with its own carrier....but for some reason never occurred to me that it would be cut for a ringless bolt.

thanks for the info...and i think i have a pretty good idea of how you "know".:D