VKTR Industries VK-1

10.5” Piston Upper Review

Gas piston upper receivers for AR15 style rifles are not new. However, they seem to be more popular now than in past years. VKTR Industries is making their VK-1 short stroke gas piston system in either complete upper receivers or complete rifles. I opted to get one of their complete VK-1 uppers in a 10.5” length. I chose the 10.5” because I like that length and thought it would be a better application test of VKTR’s products.

When you first pull the VK-1 upper out of the box, it resembles any other complete AR15 upper. That is until you look farther into it. The bolt carrier is industrial thin, dense, chrome, so it has a dull silver look to it. Then you notice the Radian Raptor charging handle. The upper has T marks on it for locating optics. Then you look inside the handguard and see the short stroke piston setup, which is why we are here. After unpacking the upper, you also notice that there is a buffer and spring in the box. The buffer weight and spring are part of the whole package to get the upper to run as smooth as possible.

Now it was time to find a pistol lower to install the VKTR VK-1 upper on. I think I went through 3 of them. The third one I just built up from a stripped Anderson lower with an SBA3 brace and a Black Talon Tactical trigger. I know, who puts a $1800 upper on an Anderson lower? Me, but had I had a Hi-Point lower, I would have used it for style points. As you can tell, the VK-1 upper will fit on any AR-15 lower receiver, just make sure it has a carbine buffer tube so you can install the supplied spring and buffer.

The VKTR VK-1 system uses a short stroke gas piston. The difference between a gas piston AR15 system, and the normal direct impingement system, is how the rifle operates. A normal direct impingement system uses gas to cycle the bolt carrier system, thus cycling the rifle. A short stroke gas piston system, like the VK-1, uses the gas to operate a piston. Then the piston pushes on the bolt carrier to cycle the action. This results in a cleaner operating system and less, if not any, gas coming back into the action. The short stroke piston system also lets the operating system run cooler. All of this lets the gun run cleaner and longer. Another advantage to a piston operating system, on an AR15, comes when using a suppressor on the firearm. Gas from the system does not get forced back into the action or your face. The VK-1 short stroke piston system allows for normal tear down and maintenance too. This is due to the operating rod not being attached to the bolt carrier. The operating rod not being attached is a huge plus with the short stroke system. The VK-1’s piston system is truly a work of art.

VKTR Industries redesigned the AR15 bolt carrier to work better. Not just because of the piston system, but in general. Since this is a piston BCG it uses a one piece carrier. This simplifies the carrier by not having to use carrier screws. It also makes the system stronger. The most unique thing done to the carrier is its long advance cam path. VKTR explains it as “The long advance cam path ensures the bolt unlocks at 22.5 degrees, thus correctly timing the locking and unlocking, allowing an additional 2 degrees of dwell time reducing residual chamber pressures, and ensuring no contact between the cam pin and receiver wall”. Since the bolt now unlocks at the proper time, you get smoother cycling and less wear on the receiver itself. The industrial thin, dense, chrome on the carrier also gives it some really good heat and wear resistant properties.

Along with the VKTR upper, they send a new buffer and spring. This buffer and spring are required for the VK-1 upper to work with all different types of ammunition, suppressed and un-suppressed. Just make sure you are using a carbine length buffer tube. Yes, it does work suppressed and un-suppressed with the supplied buffer and recoil spring.

The VK-1 uses a thermal fit barrel system. This means that the barrel and receiver are fit together with either heat, cold, or both. When assembling the upper, the upper is most likely heated up and then the barrel is pushed into the receiver. Metal expands when heated, so when the receiver cools, it clamps down on the barrel, holding it tight. This gives a higher level accuracy over a non press fit receiver. It can also cause less point of impact shift when the barrel heats up. Both of these make for a better rifle, in my opinion. The barrel of the VK-1, in this case, is a 10.5 inch 1 in 7 twist. VKTR says the barrel is a “heavy profile” with machined cooling flutes. These barrel flutes are deeply cut. Using a fluted barrel aids in cooling of the barrel, while still maintaining the benefits of a larger diameter barrel. It also lightens up the weight of the barrel. The barrel is threaded the standard ½-28 and comes with an A2 birdcage installed. The barrel is chambered for 5.56 NATO.

The last part of the VK-1 upper is the handguard. The piston operating system can get pretty hot, so the handguard has lots of large holes. This helps get rid of heat by allowing air to flow over and through the handguard. The VK-1’s handguard has a full picatinny top rail that also has holes machined in the slots for cooling. M-Lok slots are then placed at the 3, 6, and 9 o’clock positions. The length of the handguard is 9.85 inches, so it ends right at where the barrel threads begin. I thought the handguard was comfortable to use, worked well, and looks good.

Piston systems tend to be heavier than their direct impingement counterparts, or at least some do. The VK-1 is not much heavier, if any. The total weight of the complete VK-1 upper was 3.9 pounds on my scale. Making the total weight of my pistol AR coming in at 7 pounds with a 1x prism optic and a sling. VKTR lists their complete 10.5 inch VK-1 pistol at 6 pounds stripped. My optic weighs 0.6 pounds, so I am only 0.4 pounds off of their pistols weight. So in my opinion, the VK-1 upper weighs the same as any other 10.5 inch direct impingement upper.

I have about 800 rounds through the 10.5 inch VK-1 upper receiver. A couple of quick 30 round mag dumps will heat this thing up fast. The handguard, around the piston, can get hot. However, it cools off fairly quickly. Leitner-Wise makes handguard covers to help with this and they work extremely well at dissipating the heat. To be honest, the VK-1 is one of the softer shooting 10.5 inch uppers I have shot, especially for not being able to adjust the piston system. The recoil impulse is different then most direct impingement guns, and in a good way. I ran the VK-1 about half the time with a suppressor, or actually 2 different suppressors. I really like how there is no gas blowback into my face, an advantage of piston style AR’s. I did notice that un-suppressed, with low powered 223 ammunition, sometimes the upper would short stroke. This only happened a few times on me and this particular ammunition shot soft in my other AR’s as well. All the other standard 5.56 or 223 ammo I had on hand ran flawlessly, both suppressed and un-suppressed. I didn’t do any accuracy testing with the VK-1, mainly because it is a 10.5 inch and I was using a 1x prism on top. However, I could hit targets easily and transition between them with ease. I liked the VK-1 so much that I am contemplating making it one of my go-to AR15’s.

Was the VKTR Industries VK-1 upper everything I was hoping for? I would have to say yes to that question. The short stroke piston, along with the long advance cam path, makes shooting this AR15 a pleasant experience. Recoil is reduced and the upper doesn’t weigh much. The VK-1 is a top tier upper receiver and it costs top tier price, but you really are getting a great product that will last a lifetime. This isn’t my first piston AR, but the VKTR VK-1 upper is my new favorite. Go check out all their products at VKTR Industries and see for yourself.

Firearms Insider Reviews - Key Points

Claim to Fame:

AR-15 piston upper receiver

Target Market:

Those wanting a more robust operating system

Features, Benefits, and Specifications of this product:

Enhanced Upper Rail
VK-1 Piston System
Enhanced cam path BCG
Radian Weapons Raptor™ charging handle
Continuous 12 o’clock Picatinny rail
Thermal fit forged upper receiver
Thread pitch: 1/2×28
Heavy Profile Barrel: 1:7″ Twist, Machined Cooling Flutes, Nitride Finished
Low profile MLOK handguard
Includes required carbine buffer and spring

What other aesthetic options or finishes are available?

Different barrel lengths or complete rifles

What others are saying?:

5 out 5 stars at BigTexOrdnance

Okay so I’m not usually a piston AR guy, I’m not anti-piston, I have tried them all and just never thought the added weight on the front, expense, proprietary parts etc was really worth it for not a really tangible performance gain.

I listened to the manufacturer nerd out on the BTO podcast and decided to give it a whirl figuring I was getting got by good fellow gun nerd marketing .

But I can’t be happier with this rig, it’s lightweight, very well thought out design and is legit the flattest shooting out of the box 10.5” gun I’ve ever had or built. Best part is I don’t have to tune or adjust the gas system, it runs low powered .223 and hot 5.56 loads, suppressed and unsuppressed all with exceptionally low gas blow back, not just low for a 10.5, it’s lower gas blowback than some other pretty well suppressor tuned guns I have. Freaking space magic.

Only thing I haven’t done is bench it and properly evaluated it’s accuracy but so far blasting at 10yds to 200 yds it seems to be doing what it should.