Precision DMR w/ piston upper?

garandman

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I like shooting my AR suppressed, but I'm tired of the hour long process to clean it every time.

Is there a precision AR that uses a piston upper? Can a heavy barrel be retrofitted with a piston?

7081397
 

AndrewO

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Lwrc IC-Spr would probably be your best bet. They're pretty steep at $1850 an upper though. Or you could use a superlative arms piston kit if it will fit under your handguard.
 

garandman

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Surefire socom RC2.

And/or superlative bleed off gas block will help reduce backpressure and fouling.

1. I asked about a piston upper, not a can. As the pic shows, I already got a can - the one I actually want.

2. A gas block cannot reduce back pressure from any suppressor.

The S/A gas block would reduce fouling a bit, but I'm talking about fouling of the barrel from back pressure, not a dirty upper receiver. I already own a S/A gas block on another AR. They are nice, but won't help here.

Thanx anyway.
 

Potss

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Big misunderstandings here OP.

A piston upper won't be much cleaner. Most crap comes out of the chamber as it unlocks. Pistons in ARs unlock earlier when the chamber is at higher pressure as there is no gas to delay the unlock, meaning more crap comes out of the chamber into the rifle. So while you eliminate any crap coming back through the gas tube, that is like 10-20% max of the fouling you get shooting suppressed, and the earlier unlock of the chamber with a piston system (any piston system although which will matter a bit) will more than likely make up that difference (not to mention it will be louder to the shooter).

So while yes you could retrofit on a Superlative Arms piston kit, you wouldn't see any net gain in terms of cleaning, and have some other negative side effects. You would see the same or more benefit by simply adding an adjustable gas block like a Superlative Arms AGB, which will not reduce back pressure but will delay unlock which means the pressure has dropped further by the time the bolt finally unlocks which means less crap in your rifle. That is your best option to mechanically reduce the crap. If you really want to go all out you can get an LMT Enhanced carrier which will delay unlock a bit more, but you are talking serious diminishing returns.

The real solution is twofold:

1.) Stop cleaning your rifle so much and so thoroughly. I and many other on this board shoot ARs suppressed for hundreds or thousands of rounds with no issues. Just add a bit of lube and it should be good to go. When accuracy starts to drop off a bit, simply clean the barrel as per normal.

2.) Get an ultrasonic cleaner. This is the penultimate solution for those who hate cleaning. It literally does 98% of it for you. So if you have to be OCD about your rifles cleanliness, just pony up for a decent one.

And I know you don't want can recommendations, but the can's back pressure can make a huge difference in the amount of fouling you see. An OSS or similar ultra-low back pressure design (like the Nexgen) will basically mean no extra cleaning beyond what you'd get on an unsuppressed rifle. They come with their own set of issues like being heavier/longer per db reduced but it doesn't sound like that is a huge issue for you.
 

garandman

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A piston upper won't be much cleaner. <snip>

That's very helpful. Thanx.

I'm running a SA adj gas block. I prolly need to tune it better.

How about a heavier buffer? That should increase "dwell time" / delay the bolt un-locking, right?

The Ops Inc can I'm running is a pretty high volume can. And yes.... I'm looking at just focusing on cleaning the barrel.

Thing is.... I get a decent 5-shot group from one handload, then I try o repeat it and the group opens up. So I can't tell if that's due to a dirty barrel, or a lucky earlier group....
 

Potss

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My pleasure.

A heavier buffer will delay unlock, but also requires the gas to be turned up a proportional amount to cycle the additional mass. There is a balance and what is the appropriate weight for a given gas system length is still debated, especially when suppressed. Suffice to say you'd still find the gains minimal at best in terms of cleaning. Unless you are running a very lightweight buffer (like a TACCOM) I'd say you are probably find with what you have. Maybe step up one level. Tuning the block should help a bit.

Your accuracy issues don't sound like a barrel cleanliness problem. Usually a dirty barrel will be more consistently inaccurate, as in you notice more fliers or groups start to open up and/or POI starts to shift slightly. Sounds like another issue(s), too many possibilities to really speculate. Just take as many variables out of the equation as possible till you are only left with a few (barrel, ammo) and go from there. I'd also try testing different loads and factory loads to get a baseline.
 

garandman

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Your accuracy issues don't sound like a barrel cleanliness problem. Usually a dirty barrel will be more consistently inaccurate, as in you notice more fliers or groups start to open up and/or POI starts to shift slightly. Sounds like another issue(s), too many possibilities to really speculate.

I am embarassed (but happy) to report my barrel was loose...I discovered it this very morning. Embarrassed I didn't locktite it I guess.... happy to have a tangible solution as I been chasing my tail on a good load for this rifle.
 

Primus

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Do not loctite a barrel for the love of God. Use a good moly anti sieze on the threads and torque to spec.
 

Dev L

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Shouldn’t need that either.

A heavier buffer should delay unlocking and help keep stuff clean.
No it won't. Shooting with a can makes for a filthy gun. Piston makes for a clean non suppressed gun. Heavy buffer, piston, both... if you use a can on a semi auto your gun will be filthy and so will your mags. There is no avoiding it.
 

Potss

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No it won't. Shooting with a can makes for a filthy gun. Piston makes for a clean non suppressed gun. Heavy buffer, piston, both... if you use a can on a semi auto your gun will be filthy and so will your mags. There is no avoiding it.

As discussed above, this is not true. A piston gun is not clean suppressed, not by a long shot. Cleaner than an untuned DI maybe, but not by a whole lot when you have a proper DI setup, if at all.
 

RyanScott

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No it won't. Shooting with a can makes for a filthy gun. Piston makes for a clean non suppressed gun. Heavy buffer, piston, both... if you use a can on a semi auto your gun will be filthy and so will your mags. There is no avoiding it.
Have you never had a gun ported and buffered for suppressed use only? It’s only slightly dirtier than unsuppressed and lube stays wet a lot longer than a typical suppressed rifle.