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Anyone build a Piston AR pistol?

This topic can be found at:
https://sigforum.com/eve/forums/a/tpc/f/630601935/m/3270072264

October 20, 2019, 11:24 AM
Jasper1323
Anyone build a Piston AR pistol?
Morning,

It always happens... I read up on stuff and then I want one. I am weak! What are the pros and cons to a DI vs Piston pistol. Are they the same as they are for a rifle?

Thanks in advance.
October 20, 2019, 11:30 AM
12131
Same pros and cons. An AR "pistol", let's be honest, is really a SBR in disguise.


Q






October 20, 2019, 12:27 PM
Jasper1323
Thank you.
October 20, 2019, 01:30 PM
craigcpa
Have a 7.5” Adams Arms upper on a PSA lower pistol. Haven’t shot it but will reiterate in advance: it’s heavier than a DI upper.


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Just my 2¢
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October 20, 2019, 06:23 PM
RHINOWSO
For the large majority of users, a DI AR is the way to go.

More common parts, lighter, etc.
October 20, 2019, 07:12 PM
MikeinNC
I have a DI AR Pistol for all the reasons you need one...anddddd
It doesn’t need ATF approval to cross state lines, neither does my suppressor, and since I clean my guns on occasion I’m not worried about having gas inside the receiver...so I saved some money for not having to find and tinker with the piston system



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October 21, 2019, 06:39 AM
Jasper1323
The main reason I am considering a Piston is that I am left I dominate and the gas in the face.
October 21, 2019, 07:46 AM
Anubismp
Are you sure you want an AR? There are plenty of platforms with no gas to the face that may more easily support a lefty. To address your initial Q I looked into piston ARs a long time ago and abandoned the idea after a bit. I love piston guns but I have learned I generally prefer running a system the way it was designed. I prefer my ARs DI even for the suppressed stuff. If you stick a bunch of other parts into a system they dont tend to run optimally and often lead to the issues you read about. If you are dead set on it then please report your findings after you build and best of luck but I've heard far more issues than success stories.
October 21, 2019, 08:47 AM
ARMT Guy
Haven't built a piston AR pistol, but have built a shit ton of DI AR pistols.. even one for my self. Big Grin

As a long gun lefty, I've never been bothered by excess gas from an AR going on thirty some odd years now, ( unless it was suppressed. )

Now, if you wanted to go the piston AR pistol route, take a look at PWS's offerings.




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October 21, 2019, 02:32 PM
AH.74
quote:
Originally posted by craigcpa:
Have a 7.5” Adams Arms upper on a PSA lower pistol. Haven’t shot it but will reiterate in advance: it’s heavier than a DI upper.


I have the same on an Aero lower. I allowed myself to be talked into getting it by two separate friends, so I listened to the advice and I'm glad I did. It's pretty cool. I also have a standard DI 10.5" Pistol so getting something different seemed like a good way to go at the time.

Advantage over a DI is the adjustability- if you choose that option. Mine has 3 settings- normal, single-shot and suppressed. Just turning the end piece is all you need to do.

It is indeed heavier than a standard DI upper. Bear in mind also that these shorter lengths are especially "loud as fuck."

One other piece of advice I heeded- going with steel backup sights. The gas port and surrounding areas (heat shields) can get very hot.


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October 21, 2019, 05:34 PM
fritz
All other parts being equal, a piston upper will be a little heavier than a DI upper. Perception of this weight difference is personnel -- it may, or may not, make a difference to you.

The BCG of a piston upper will remain cleaner than than of a DI. This is especially true if you will shoot it suppressed.

A piston upper will likely blow less gas back at you, especially if you will shoot it suppressed.

I find DI uppers to have slightly smoother recoil and slightly better accuracy than their piston counterparts, but this is with longer barrels testing accuracy at extended distances. For most shooters -- and especially for pistol-length barrel uppers -- this likely isn't anything that will be noticed.

IMO the nicest thing about a piston upper is how easy the BCG cleans and how well the BCG stays lubed.

The downside to a piston upper is the lack of standardization. If you go with piston system, understand that one company's parts may not work with any other brand on the market. I recommend buying a complete upper, should you decide to go piston system.
October 21, 2019, 06:11 PM
smithnsig
Stag LH upper and BCG. Faxon barrel extensions are ambi cut so they work well with LH bolts.


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TCB all the time...
October 22, 2019, 07:33 AM
gearhounds
I have a 10.5” Adams piston upper on a PSA multi-lower. It has the heavy MG barrel and not exactly light, but is a good accurate and reliable shooter.

As to these being “SBR’s wolves in sheep’s clothing”, the most interesting thing is that they prove that SBR-ish devices are simply not used in crimes any more than any firearm type. Which begs the question, why do they need regulation?




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