New Custom Upper with Superlative Arms Piston System

[Double Naught Spy]

Bryan of Bryan's Tactical in Minnesota asked if I would be willing to field test improvements to an upper that I asked him to build for me. Silly question.

The following components were used in the upper.

Aero Precision Receiver
Superlative Arms Piston system
AR Performance 18" midweight barrel
AR Performance enhanced Bolt
Bolt nickle boron treated by Fail Zero
Silencerco flash hider/suppressor mount
Midwest Industries M-Lok narrow handguard with rails and covers
Strike Industries charging handle with extended latch

Unit was function tested and the piston system tuned with 40 rounds of factory Hornady SST 123 gr ammo (my preferred hunting round) using a Silencerco Omega suppressor like I use.

Pictured is the upper with the Leupold scope with which I will be doing my initial accuracy and function assessment. If all goes well, I will be removing the Leupold and replacing it with a thermal scope for hunting. This will become my primary hunting rifle in order to field test it. Bryan creatively stated that if it can hold up and continue to shoot well with the way I treat my guns, then he would be trying the piston system on some of his other uppers.

My concerns center around the perceived lack of accuracy with piston AR uppers, reliability of the system, and how it works overall for hunting. The perceived lack of accuracy aspect for piston guns seems to be a fairly heated topic with guns affected negligibly to a 1/2 moa or so with various factors being claimed. Reliability, particularly when suppressed, is a real issue. As a piston system, the chamber will run cooler and cleaner and hopefully the ammo will remain much cleaner in the magazine. Firing a suppressed Grendel with a regular DI gun results in the subsequent rounds becoming downright nasty with soot and corrosion (?). I am hoping this will be eliminated using the piston setup.

As for the folks who despise AR Performance, I have read the posts. This was the barrel provided with the upper. I got to choose the barrel length, color, handguard, and flash hider. I know some folks have some doubts about piston systems. I do, too. However, I am getting to do some real world field testing on somebody else's dime.

Here is the setup as it will be initially tested with Silencerco Omega suppressor. I will keep y'all posted on how it turns out.

Group.jpg

[Kilco]

Looking forward to your results. Certainly is a real nice looming setup.

[Arkhangel5]

DNS,
Will you be shooting factory only or self loaded ammo? What is your accuracy requirement for your equipment to be used in a work situation?

Do you have an idea of the weight differential to a similarly equipped DI setup?
.

SY
Am interested to see how this works out for you

[Double Naught Spy]

Arkhangel5, I do not reload, so I will be shooting primarily factory ammo.

What is my accuracy requirement? I typically like to have sub MOA guns. My worst gun shoots Hornady SST 123 gr. at 1.5 MOA. I can live with that. The same rifle does much better with some other ammo, but I hunt with SST, usually.

No clue as to the exact weight differential. The main difference is going to be the op-rod that drives the BCG from the gas block, which will be slightly heavier than a normal one. To be honest, such a minor difference in weight was never something I gave a second consideration.

[TheDroz66]

I too am looking forward to hearing your results! I just received my Superlative Arms piston system in the mail today and will be putting it on my 12" Faxon Build. Keep us all posted. Thanks!

[just_john]

Some folks have more fun than the rest of us are allowed to! Am very interested in your conclusions.

[sreyemj]

What is my accuracy requirement? I typically like to have sub MOA guns. My worst gun shoots Hornady SST 123 gr. at 1.5 MOA. I can live with that. The same rifle does much better with some other ammo, but I hunt with SST, usually.

It's nice to have gun that shoots MOA every once in awhile, partly why I haven't tried any piston systems. Kind of think the accuracy difference has been over sold with mostely anecdotal evidence.

[Double Naught Spy]

Did not have time for much extensive testing. Had to get the Superlative Arms piston adjusted for with my gun. There is some complexity to making the adjustments, though making them is easy. You can turn one way and cut pressure like a regular adjustable gas block or turn the other way to bleed off pressure. I went with the bleed off adjustments. Finally found a sweet spot that would cycle and lock back both Wolf Gold ammo and Hornady SST 123 gr. ammo. The Wolf did very poorly. The Hornady SST gave me 1.25-1.5" groups @ 100 yards. That will work for hunting purposes.

I don't know how the groups would have been had I run the same barrel in a direct impingement setup, but these results are not outside of the normal for what I would expect from factory SST.

The real benefits of the system are the cooler bolt and BCG, less grime, and the ammo in the mag doesn't get nearly as grimy either, which is a big deal because I am running a suppressor. There is also less gas in the face. The only times I really noticed any was after the bolt locked back and smoke wafted from the chamber.

[just_john]

Wafted? Thought that came with eggs at Denny's.

[Double Naught Spy]

Would you prefer...

Some smoke issued forth from the chamber, hung in the air, shifting sensually as if it t'were a feminine ghost drifting on a gentle breeze as it obscured the chamber like fog in an alley on a humid night. And then it was gone.

[Drillboss]

Uhhmm, let's stick with wafted.

I'm feeling a little uncomfortable.

[Kswhitetails]

I too am looking forward to hearing your results! I just received my Superlative Arms piston system in the mail today and will be putting it on my 12" Faxon Build. Keep us all posted. Thanks!

I want input from you once you get your system running. I'm either going Superlative or Adams. Leaning Adams so far because I already have one on my S&W PSX. Want the input though. Hit me up when you get around the range.

[JDub]

Some smoke issued forth from the chamber, hung in the air, shifting sensually as if it t'were a feminine ghost drifting on a gentle breeze as it obscured the chamber like fog in an alley on a humid night. And then it was gone.

Damn, Son! We have a warrior-poet in our midst! Give us a stanza or two about the sweet release of death you inflicted on some poor piggies.

[Sticks]

Nah, his daughter wrote that.

[Double Naught Spy]

I want input from you once you get your system running. I'm either going Superlative or Adams. Leaning Adams so far because I already have one on my S&W PSX. Want the input though. Hit me up when you get around the range.

Here is the interesting part. Starting with the valve adjustment screw turned all the way clockwise, you back it off 4.5 turns and that is the point where there is maximum gas pressure. If you turn clockwise, you are shutting off pressure to drive the piston, much like a regular adjustable gas block would do (restriction mode). If you turn counter-clockwise from the the max pressure spot, you are bleeding off pressure from the piston, much like SA's adjustable gas blocks do. The advantage of bleeding off pressure is that less the gun runs cooler, quieter, and cleaner, although all of these are not huge differences. The disadvantage is losing a few fps in the process. One tester on Youtube found a 20 fps difference between running the gun in restriction mode versus bleed-off mode.

The nice thing about how the adjustment screw works is that it is not subjected to any of the GSR, just like their adjustable gas blocks. That means that the screw will no seize up with residue like many other brands of adjustable gas block. My Syrac was seized by after about 40 rounds and I am told that I am going to have to heat it up with a torch to get it unseized if I want to adjust it. Penetrating oil and the like won't budge it.