I have a good, reliable Rock River AR-15, and I have a SCAR-17. I really enjoy both rifles. I do not enjoy cleaning both rifles. I recently brought home a .30 caliber suppressor, and it will see some time on any 5.56 rifles I happen to have from time to time.

I really like how clean the SCAR stays by virtue of being a piston system.

For a 7.62, I like the SCAR, as I think it offers one of the most robust and lightest 7.62 platforms out there.

In 5.56, I'm less sure of the SCAR's superiority. My 16" AR feels considerably more handy than the SCAR, and it looks like the weights of piston AR platforms have come down (in both 7.62 and 5.56 calibers, actually...)

So, if I buy another 5.56 rifle, I want to be reasonably assured that it will have reasonable market and manufacturer support for some time, and parts availability. It doesn't seem like there's a whole lot of standardization among piston ARs, unfortunately. So, what are some good options?


SCAR-16s? I like my 17, and getting a 16 is probably the front-runner. There is some parts commonality between my 17 and a 16, and I already have a feel for the system. I feel reasonably confident that the SCAR platform will be around for a while.


Sig MCX - I think this rifle has promise, and it seems to offer a lot of what I'm after. I just don't trust Sig to not discontinue the gun or change it up enough in a year or two that it turns any rifle I would buy now into a one-off and eliminate any chance of future support.


Other Piston ARs - I'm kind of lost here. Who is doing what now, and doing it well? LWRC is a well known name, and I like the features, but it would seem to be in the same situation as the MCX. The promise of future support would be sketchy.

Adam Arms? PWS?


Or, should I just buy some more Hoppes and Powder Blast, and clean my AR more?

I haven't had the opportunity to play with a SCAR, but my buddy got an MCX a couple of weeks ago, and we put it through the paces at the range. That this is one incredibly smooth shooting rifle. The piston system and Sig's recoil system that does away with the buffer tube and replaces it with the dual-spring system internal to the receiver is phenomenal. And it is definitely cleaner.

There were two things I didn't care for:

One, the handguard is way too big around, and kind of heavy. Very fat and uncomfortable. His was designed to go around a supressor, so that may be a factor...not sure if they offer a slimmer, lighter option for other applications.

Second, he has the folding stock that also collapses for adjustible length. The folding feature worked well, but the buttons to collapse the stock were stiff, cumbersome, and difficult to operate.

The design shows a lot of promise, but there are a few things they need to iron out to get it right, imo. I couldn't see myself paying the extra premium over an AR for what he got in the MCX as it stands right now.

I have the SCAR17s, and it is a great platform. I can only assume the SCAR16 would follow the same dynamics. Clean, suppressible, and fair support.

I have the SIG 516 AR and it is hands down the cleanest rifle I have. It uses a piston/push rod system that contains contaminants and particulates very, very well. I am not sure about parts availability, as is the case with most SIG platforms. They seem to be a fickle mistress when it comes to their own product loyalty.

I have the MCX and it is simply dirtier than other piston guns I own. I'm not sure why, but it is just not as clean. Other than that, it is a great platform, and suppresses well. Also, SIGs loyalty to their own products is always an issue.

H&K-Guy

I have the following:

FNH Scar 16
Sig MCX
Sig 516
Barrett Rec7
HK MR556a1

Out of all of these - I'd recommend either the scar or the barrett.


The scar has been around for a good while now and has enough of a following that I don't see that changing any time soon.
Parts are fairly readily available - as well as some damn good aftermarket options (PMM, KDG, Geiselle, etc...)

The MCX is a great gun. I have 2 (one of which I SBR'd into .300blk). It's super lightweight and it's got growing aftermarket support. That being said... Sig is kinda known for just yanking the rug out from under you and changing/discontinuing stuff.
(with regards to the comments above about the chubby rail - yes the suppressor ready one is fat as hell. the normal one is MUCH friendlier to handle. Also there must be something wrong your buddies stock - mine works perfectly fine.)

Sig 516 - Pretty basic piston AR. Proprietary rail system with very little aftermarket support. Has been discontinued by sig

Barrett has been around for years. They're not going anywhere. Their customer support is top notch (know this myself from experience). The rec7 is also a pretty basic piston AR. There's nothing real groundbreaking in the design compared to others of the same type. Quality of manufacture is quite good though.

HK - runs like a top. A bit on the heavy side. Parts availability and aftermarket support isn't bad. The biggest downside IMO is the fact that it's finicky about mags. Magpul gen2 wont work - must be gen3 (because european). It's also a damn expensive gun in comparison to the others (although the scar has been rapidly creeping its way up there too lately)

...on the SCAR price creep -

I seem to have a bad habit of going after these things when the prices start climbing.

So far, it's sounding like the SCAR-16 is what I'm after, if I do this at all.

Although I have both a SCAR 16 and 17, I’m not convinced of their greatness, especially suppressed. You usually have to play with swapping gas jets on the 17; don’t know if it’s the same on the 16. Plus, they have lightweight barrels. Shooting unsuppressed, the SCAR is a no-brainer, but suppressed a bit more uncertainty.

The HK MR556 is nice, but it’s heavy, and doesn’t come with an adjustable gas regulator.

Have a LWRC M6A3, but that model has been discontinued for a while now.

Just picked up a PWS Mk111 Pro upper, which seems a good value for $600, but haven’t shot it yet. If it runs like I hope, this might be my go-to 5.56.

The Adams Arms is passable but not great. Worthwhile if you find one on sale, and you can often find one on sale if you wait just a bit. You'll definitely like it from a cleaning perspective.

+1 on cleaning being way less of a pain in the butt with a piston gun. The trade off is a little weight. My DI AR is lighter, but lets be real, I'm not humping 20 km patrols.

+

Scar 16 is my first choice which is why I have a few of them.

LWRC M6 IC-SPR would be my second choice, especially if you were looking for the slim/handy feeling of an AR when compared with the bulkier Scar. I’ve been very impressed with the quality and fit/finish with all of my buddies LWRC rifles and plan to get one myself.

If you plan to shoot it suppressed look at the LWRC IC-A5 instead for the adjustable gas valve.

My Sig 516 is solid, reliable, and very accurate, but a little on the heavy side for an AR.

I like the MCX and have shot my buddies frequently but the LWRC is a bit higher end.

My first recommendation would be the SCAR 16s. It would be my top choice. There's that article from the gun rental place in Las Vegas where they said the SCARs are among the most trouble free carbines in their inventory. Also, I read an article by David M. Fortier titled "On the Range" where he shot a SCAR 16s at 500yds. and got a 4.2" group with Black Hills 77gr. Mk262 Mod 1 ammo. I think the user replaceable gas jets are a big advantage as all gas operated rifles are going to erode the gas port. For others, it means replacing a barrel. On a SCAR, it's a gas jet.

Other options include:

B&T APC223 - As far as support, I think B&T is gaining in popularity. One thing does give me pause is that while they have upgraded their APC offerings to the 'PRO' models for the 9,45,10, and .308. For some reason I haven't seen an APC Pro version in .223/.556 or .300BO. Not that's a deal breaker, just makes me think that if I bought one, they'd immediately release a 'Pro' version with my luck.

LMT Piston AR - Seems like it would be a quality AR based option.

HK MR556 - Would be best as a DMR/Accurized carbine as they are very accurate rifles. They don't have a chrome lined barrel so they're not something I'd consider doing mag dumps with. Also, my MR556 bone stock is heavier than my SCAR 17. That's ridiculously absurdly heavy for a .556 carbine.

SANSwiss SG551P - They are out there and very expensive. Saw one recently on GB started at $2275 and finally sold at $4800. They can be purchased as a pistol then SBRed and 922ed for import compliance, if you want to go that route. I wish an importer would just import them and add required US parts, but alas, not yet.

The CZ Bren 2 would also be an option. Not sure if they will be offered in a turn key ready to shoot carbine with the correct factory folding stock or not, but they seem pretty nice as well. Although, if I get one it would probably be a 7.62X39.

I have a SCAR 16 and 17. I also have some Bren's.

I'd take the Bren's.

Also, look into the Galil Ace.

Piston AR’s do not suppress well. Needs to have a specific setting for suppression- .625 setting.
Upside of piston- cleaner
Downside of piston- heavier, needs a specific suppresso4 setting.

My vote goes for the Scar, it’s so much cleaner shooting suppressed than an AR. Sure it’s more expensive but IMO it’s superior to piston driven ARs. I just got a Sandman K to leave on my 10”, it’s not quiet by any means but it knocks off a lot.

Someone above mentioned gas jets, I bought a few jets from PMM and spent about 20 mins getting it perfect, 1.7 on a 10” bbl, it’s not rocket science.

Its hard for me to suggest anything but another SCAR. I love both the 16 and 17. There are a whole bunch of parts that in common between the two simplifying spares. They operate and maintain exactly the same. The aftermarket is very robust. I enjoy shooting the 16 and with a change to ditch the big factory rails find it very handy. Barrel changes make it versatile. FN has finally made the spares situation tolerable. Of the other choices that at least I have. The MCX is a nice rifle. But I don't trust sig ever. Been burned too many times. I like the options for the stock (mine is a rifle) and its pretty easy to maintain. I have the CZ Bren, but its so limited in distribution I would not consider it. The HK is way heavy for my taste, but it meets most of what you want. Parts/support is a maybe. I don't have the Barrett piston, but I would never hesitate to buy anything Barrett. I have several other barrett guns and they are as good as it gets in terms of support, parts, etc.
I'll probably think of something else to consider, but just get the SCAR and be happy.

I own an LWRC piston 14.5" upper, have shot an LMT 16" piston gun, have shot a SCAR 16, have shot a SCAR 17.

The bolt of piston guns stays amazingly clean of carbon fouling and cool, as compared to DI rifles. The bolt carrier is a little dirtier on a DI rifle, but honestly the fouling is really occurs on the bolt.

Piston guns are almost always heavier than a comparable DI gun, with the weight being distributed to the forward end of the upper. In my direct experience and from discussions with buddies who are talented shooters, piston guns offer reduced accuracy than a comparable DI gun. The piston's reduced accuracy may not be important to some shooters. Other shooters may not have the fundamentals to see the accuracy differences.

SCAR's are decent rifles, and are reliable. I don't find the SCAR-16 or SCAR-17 to be all that accurate, especially for the price. For rifles that are supposed to made for high volume shooting, they should include heavier barrels. Accuracy suffers as the barrels heat up.

I liked the LMT I shot. Slightly heavier than a similar DI, but not a big deal. The gun was accurate -- it seemed to be up to my standards with DI rifles.

My LWRC is truly accurate with only 69 SMK loads, which is odd for a 1:7 twist barrel. It shoots match-grade ammo of other types adequately, at best. It cycles flawlessly both with and without a suppressor. I find recoil slightly smoother with a DI rifle, as compared to a piston rifle. The LWRC's bolt is almost carbon free after a few hundred rounds. Interestingly, the LWRC's barrel requires more patches to clean than my DI uppers. This increased carbon fouling for a piston gun's barrel is something I've heard from other DI/piston shooters, too.

I won the LWRC in a rifle match, so I have invested only the cost of its scope and mount. Given that all my AR shooting is suppressed, I was pretty excited with the piston concept. I'm glad I didn't buy the piston LWRC. I know I won't buy a piston rifle or upper in the future.

I have no issues with suppressed DI AR15s. Sure, the bolts get dirty after shooting. I know my DI rifles are over gassed with my suppressors. But my DI guns shoot with great accuracy -- every one with sub-MOA accuracy out to at least 400 yards with factory match ammo. Other than carbon on the bolt, the guns clean up quickly. I've never had any cycling problems.

I’m with the OP. I have a scar 17 and love it. I had a scar 16. It was clunky for a 5.56.

I looked around and finally decided on a few quality DI Guns. I’ve got DD, BCM and Colts. I just deal with cleaning it occasionally.

quote:

Originally posted by H&K-Guy:

I have the SIG 516 AR and it is hands down the cleanest rifle I have. It uses a piston/push rod system that contains contaminants and particulates very, very well.

This is one of the reasons that I love my 516 for, as well.

I have and old PWS piston conversion in a Colt that runs very clean, too.

quote:

Adam Arms? PWS?

Adams Arms works great but true they can get a bit heavy. I have build two AA units and some parts for another.
If I didn't built them I's get a PWS ~ they are an awesome product.

The SCAR 16 is a great rifle, but in 5.56 I don't think piston brings much but cleanliness and ease of cleaning.

I bought mine for $2070 new back in oh, 2011? For that price I was happy but for $2500 to spend on a 5.56 shooter, I'd buy an SR-15 if I wanted 'spensive or just go with any of the other quality rifles from $1000 and up...

Maybe you should look into the Galil ACE line.