A long-range rifle capable of a mile with a light recoil and fits in the familiar AR-15 platform? Sounds good to me, Where do I sign up?
The 6mm ARC in a compact AR-15 platform sparked my interest after having witnessed it being taken to a mile and beyond. On separate occasions with 2 unrelated companies, I witnessed this round making consistent impacts at a Mile and 2000 yards. This blew me away and my next project became a personalized AR-15 build project chambered in 6mm ARC.
The Components:
The one thing both rifles had in common was a premium carbon fiber barrel from Helix 6 Precision and that’s where the build begins. The matching receiver set is from Silencerco that features an ambidextrous bolt release and stylish flared magwell. The handguards are the Strike Industries Gridlok Lite, FAB Defense GL-Core M stock and Gradus Grip, the trigger is an RMT Nomad, and the buffer tube is a PWS Enhanced Buffer with Ratchet Lock castle nut.
Helix 6 Precision 6mm ARC Barrel
Helix 6 Precisions creates a premium match grade carbon fiber barrel with a very high carbon fiber-to-resin ratio. The high carbon fiber content increases the ability to dissipate heat and minimizes the point of impact shift over higher volumes of fire. The unique Carbon Fiber application is a structural component of the barrel that seems to create large and forgiving accuracy nodes. As you can see in the photo below, this gives consistent results over a wide range of ammunition. This is 3 completely different loads with very similar group sizes. I’ve used Helix 6 Precision barrels on several other builds and another quality that I enjoy is the ability to cut a blank to whatever length I want.
Silencerco Reciever Set
The barrel is matched up to a 7075 billet aluminum SilencerCo receiver set that’s loaded with cool features. The lower receiver sports an integrated ambidextrous bolt-catch release, flared Magwell, and an enlarged trigger guard. The lower also includes integral and ambidextrous anti‑rotation QD sling cups and a rear tensioner to tighten up the fit with the upper receiver.
The upper receiver is a perfect match to the lower receiver and is generally the same as a mil-spec upper that is overbuilt and matches the lines of the lower receiver. One problem I had with the upper was a loose fit with the barrel extension. I didn’t notice it during the assembly but the initial shot groups and load development didn’t produce the expected results. I know the Helix 6 Precision barrels perform and that’s when I reached out to Jon Beagle for some guidance. He suggested I check the fit of the barrel extension and upper receiver. I found the barrel slid out pretty easily and based on his suggestion I added Locktite 680 Retaining Compound to remove any slop in the fit. That trick cut the groups down from 1.5MOA to consistently sub-MOA.
FAB Defense GL-CORE M Stock
The GL-Core Mag is a carbine stock that incorporates an integrated push-button magazine carrier. The extra mag is located just in front of the butt pad and is tucked away so it doesn’t easily snag and creates a butt hook for the non-firing hand. This is a compact stock with a smooth and streamlined look that includes flush cups for a sling, an anti-rattle mechanism, and a high-quality rubber butt pad. The CORE M will take any standard AR15 magazines including 6.5 Grendal or 6mm ARC magazines. The stock is mated to the PWS Enhanced Buffer tube with a ratchet lock castle nut.
FAB Defense Gradus Grip
The FAB Defense Gradus grip is one of my all-time favorite grips. It has a vertical and curved profile that is comfortable whether I’m standing or lying prone. The vertical position also lends itself well to a clean straight-back pull of the trigger lending to more consistent impacts down range. The Gradus grip is rubberized with grooves and a texture that helps maintain a positive grip when sweaty or dealing with rainy conditions.
Strike Industries Gridlok Lite handguard
I wasn’t sure how I would like a quick attach handguard but it had some great features at a reasonable price so I took a chance. The quick attach feature came in handy when I was troubleshooting the initial precision issue and the system locks up nice and tight. The handguards have M-LOK slots at the 3, 6, and 9 o’clock locations and has a built-in flip up backup iron sight (BUIS). The rear tabs have set screws at the top of the SI GRIDLOK® LITE to help maintain proper top rail to upper receiver alignment. In the rear of the handguard, you will also find an integrated 360° free swivel QD socket for a 2-point setup.
Range Performance:
One thing that makes life much easier is having a rifle that will shoot great with a variety of ammunition. The first day out after bedding the barrel extension proved that the accuracy problem had been solved. We shot 3 different types of ammunition that all produced similar sub 3/4th MOA groups at 100 yards. I was able to replicate these results during the following range session, only this time I did it with the camera running.
Tight shot groups are always great to show off and are needed but reliable functioning is probably even more important. To test reliability I ran suppressed and didn’t clean or lubricate the rifle for a little over 100 rounds of use. After about 100 rounds, I had a few empty shells not clear the ejection port and jam up the rifle. A quick field strip of the bolt carrier group with a wipe down and a shot of lube got everything running great again. I’m never very good at keeping my rifles clean but it’s nice to know at what point I will start running into trouble.
In conclusion, this build has been a joy to shoot and work with and I am very happy with the performance. I wonder how well it would shoot if I had better focus and discipline in my fundamentals. Seeing shot groups with a couple touching and then one round off on its own makes me question my consistency behind the trigger. Either way, it shoots great and I think any improvement will come from me as a shooter rather than anything I could do to the rifle.