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Posted: 7/20/2008 4:09:58 PM EDT
saw one at a shop today, and it looked very nice.....wanted to know does anyone own one? any pros or cons? whats the word on these thanks
Link Posted: 7/21/2008 3:14:26 AM EDT
Link Posted: 7/21/2008 3:47:50 AM EDT
I didn't know CMMG made a piston AR.

Does anyone have a link that tells more about it?
Link Posted: 7/21/2008 4:29:17 AM EDT
Probably a CMMG lower with someone elses piston upper attached.
Link Posted: 7/21/2008 5:00:25 AM EDT
After the sand test I inquired in the CMMG industry forum if they (CMMG) planned to manufacture a piston driven upper. They responded that it was in the works or something to that effect. You can probably dig it up in the Archives. However, I doubt that a CMMG piston upper would have already made it to your local gun store without some fanfare on the CMMG website and the industry forum as well.
Link Posted: 7/21/2008 5:26:52 AM EDT
Link Posted: 7/21/2008 6:34:11 AM EDT
If you can find the RSR ad in the EE, it's indeed a CMMG Piston driven 16" Carbine upper (iirc, they also came with double heatshielded handguards as well).

I'll find out which piston system (PWS I think) it used
Link Posted: 7/21/2008 6:39:15 AM EDT
I know what I saw......it was a CMMG gas piston rifle, and yes there is one at my local fun shop........any pros or cons greatly appreciated
Link Posted: 7/21/2008 8:09:06 PM EDT
I stand corrected. Very cool!
Link Posted: 8/23/2008 8:49:35 PM EDT
New to forum and this is my first post. That aside, I picked up a CMMG gas piston upper at a local gun show. I already owned a CMMG AR15. It was by chance that they had a few of their new production uppers made specifically for the gas pistion system. The new ones are not retro fit. The system is made to their specs by Kodiak Rifleworks. It is my understanding (second hand info) that they will eventually bring production in house. It is their design, but they weren't setup to produce them in large enough quantity. If this is the truth, then I'm glad they they didn't delay release pending tooling their production facility.

I have not had an opportunity to fire it yet, but plan to lug 300 rounds of ammo to the range tomorrow. Hopefully I will have time to shoot it all, but that will depend on how long it takes to sight it in. I'm taking a mix of cheap crappy ammo, reloads, Federal 65 grain and whatever else is rolling around in the bottom of the ammo box.

Their conventional upper had no issues with the aforementioned ammo, so I don't expect any with the new GP upper. I am particularly fond of the W.A.S.P. coating that they use. I have heard that it's phenomenal stuff. Since this was, I'm ashamed to say, an impulse buy, I don't know too much about the coating other than it's supposedly the best stuff man has ever created. I'm guessing it's a bit of an exaggeration, but we'll see.

I'm anxious to hear other opinions on this upper. No question that it's overkill for a hobby shooter such as myself, but my dad always told me to buy the best you can afford and buy it once. He was buried with his Snap-On tools.
Link Posted: 8/24/2008 12:34:49 PM EDT
Bought 1 just recently, have yet to get to the Range> They did a real nice job on this rifle as I have diassembled and cleaned. I really like the Gas Block config.
Link Posted: 8/24/2008 12:43:57 PM EDT
What are they selling for ??? TIA...........
Link Posted: 8/24/2008 12:51:39 PM EDT
I believe MSRP to be approx $1200.00
Link Posted: 8/24/2008 1:28:10 PM EDT
Seen one nice if you like gass.
Link Posted: 8/24/2008 2:05:46 PM EDT
M4LEP is the one out right now. RSR is the primary distributor, but I've seen a couple for sale elsewhere, usually 3rd party, or GunBroker.

There are etherweb whispers of their upcoming project for a piston driven system in a higher caliber as well...

I'm hoping CMMG will get some fancier pictures of that setup, especially with an added rail system or something [Hint DD FSP Rail, lots of Magpul/TD stuff]
Link Posted: 8/25/2008 4:38:43 AM EDT
I'm eyeballing one right now at my local shop. I think the price is a little over $1000, hopefully its still there next payday.
Link Posted: 8/25/2008 9:43:23 AM EDT
For those interested have your dealer call RSR, they have them in stock.
Link Posted: 8/25/2008 11:04:14 AM EDT
we need pictures!!!
Link Posted: 8/25/2008 11:59:42 AM EDT
I like the Adams Arms piston retrofit kit just have to find a price.
Link Posted: 9/2/2008 6:16:53 PM EDT
memlapse & mminnv,

I've been looking online at the gun you bought for a couple weeks hunting
Is there an owners manual you could share? (to save most of my questions)
Is the piston system adjustable like the Adams and the PWS?

Range report?

Many thanks!
Link Posted: 9/2/2008 8:29:13 PM EDT
Link Posted: 1/19/2009 10:45:32 AM EDT
Anyone have a range report?
Link Posted: 2/26/2009 11:42:15 AM EDT
[Last Edit: 2/26/2009 11:44:36 AM EDT by skyungjae]
I know this doesn't belong here, but some of you might be curious about their retrofit kit.

I ordered my CMMG gas piston kit and upper during election day last November. This is my set up...

16" CMMG upper receiver
CMMG gas piston kit
MATech rear BUIS
MI front BUIS (rail height)
MI MCTAR-20P rail (this rail is designed to clear the piston system)
Bushnell holosight (EOTech knock off)

Since I've had it, I've been to the range a handful of times. Keep in mind, I'm doing this off memory and most of my data is a few months old.

$450 at the CMMG website (not sure if the prices have changed)
I especially liked how it came with it's own bolt carrier.
Pretty simple installation: If you know how to remove a gas block, you can do this. I actually took off my barrel completely since I didn't want to cut my delta ring for the rail system.
Being able to service the piston from the front with just an allen wrench.
That being said, there aren't many parts to it. Once disassembled, there is the plug, washer, piston, and spring.
Easy to service and clean the parts.
Can go approximately 1500 rounds before cleaning (haven't tested this since I just clean it every time)

There is some buffer tube wear like other retrofit kits. It's rubbed off the finish inside the buffer tube, but it hasn't gouged out any metal. After I put another 500 rounds through it, I'll get back to you on how bad it really is.
Parts need to be replaced...after about 7500 rounds, it's recommended to replace the piston return spring. It's not a big con, since you'll probably need to replace other parts after that many rounds through your AR.
At the time it was only available for 14.5"-16" no mid-length or rifle length. Not sure if that has changed.
Weight, but all the gas piston kits and rifles weigh more.

Since I've installed it, I've fired about 500 rounds through it. Unfortunately I've never fired the upper in its original form to make any comparisons. I can tell you that I haven't had any failures what so ever, not even from the magazines. I've tested American Eagle XM193, PMC, and Remington all 55gr FMJ. From the standing with a modified hasty sling, I was able to keep all the groups under 6 inches at 100 yards using the Bushnell which I find acceptable in that shooting position. I also didn't have a problem hitting metal silhouette targets out to 600 yards from the prone using the BUIS. I doubt that the MOA has changed much from the original direct impingement configuration.

All in all, it's a tidy system. If I could do it again, I probably would. I am very curious about the Adam Arms kits in other lengths. That's probably because my other two ARs are 20". In the summer I will be putting together another 16" with the Adam Arms kit for one of my friends. I'll be able to make a better comparison then. Another thing I'd like to add is that the retrofit kits, as awesome as they are, aren't the same as native gas piston uppers like the LWRC M6. I spent nearly the same amount of money on my upper, piston kit, and rails. I could have gone with LWRC, but I like knowing my rifle inside and out.

These are some pictures from last December. The rifle hasn't changed much since then. I added a light and pressure switch, but that's it. Sorry for the low res.

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