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Helix 6 SIG Sauer CROSS Pre-Fit Carbon Fiber Barrels [Hands-On Review]


The SIG Sauer Cross is a cool rifle with a fairly simple idea. Lightweight, modern, user-friendly, and good quality.

Our review of the Cross was really positive, and so was our review of the Cross PRS. But just because something is good doesn’t mean it can’t be better.

Helix 6 is a recognized brand when it comes to carbon fiber barrels and we were pretty excited when they announced they would be making pre-fit CF barrels for the SIG Cross.

How do they shoot? Are they worth it? 


  • SIG Sauer Cross Prefit Barrel
  • 416R Stainless steel cores wrapped in carbon fiber
  • 6mm Creedmoor 20″, 1-8 Twist, 2lb 5oz
  • 6.5 Creedmoor 18″, 1-8 Twist, 2lb 2oz
  • 308 Win 16″, 1-10 Twist, 1lb 15oz
  • MSRP $1,450


Getting this barrel on my rifle was pretty painful. None of that is Helix 6’s fault, and they even went way out of their way to help make this review happen. Not only did they provide a barrel, but they ultimately provided gunsmithing services as well.

If you’re not familiar, the SIG Cross really isn’t designed to be use-serviceable. And, in classic SIG fashion, they’ve made a number of internal design changes that they didn’t really tell anyone except their armorers about.

In theory, changing the barrel on a Cross is pretty easy. A dozen screws to take off the handguard and optics rail, an AR-15 pattern barrel nut, and the barrel comes off with little fuss. Up to this point, I was able to do it all in my gun room.

However, the barrel requires a barrel extension that is held on with a captive nut. This is where things went off the rails for me. SIG doesn’t actually sell the barrel extension separately, so the standard practice right now is just to use the extension off of your old barrel when you re-barrel a Cross.  Normally, this isn’t a huge deal. Twist it off, and you’re good.

For me, it was a nightmare. 2 months of fighting with it, 4 broken tools, calls to 5 gunsmiths, and that damn nut just won’t come off for me.

For the first time, I was ready to call it quits. I was ready to give up. I sent a note to Helix 6 and said no mas.

Thankfully, they actually had a spare barrel extension lying around and offered to send it to me so I could use that for the review. Happy day! Review saved!


Unbeknownst to me, SIG has made multiple revisions to its barrel extension and bolt design since releasing the Cross. Turns out, the extension Helix 6 offered me didn’t fit my bolt. Not their fault, just SIG doing SIG stuff.

Ultimately, I sent both my OEM barrel and the Helix 6 barrel back to Helix 6 so they could take a crack at getting my extension off the OEM barrel and onto their barrel so I could finally install the barrel on my Cross and give it a test.

Thankfully, their tools and techs are better than I am, and they were able to get it done.

For you, your path to barreling a Cross should be a lot easier. From what I’ve read and heard talking to other gunsmiths, my case is an extreme outlier. Normally, the nuts come off super easy and with minimal effort. I just got unlucky.

That said, if you go down this path — you should know what you might be getting into. Rebarreling Cross rifles isn’t as common or standardized as some other factory options. 


Before hitting the range, I gotta say just how good the Helix 6 barrel looks. Part of the reason to get a CF barrel is because of the drip, and this Helix 6 delivers on that.

I normally use a Bushnell Match Pro ED on my Cross, and it’s a bit heavy for what is a lightweight hunting rifle. However, my goal for my Cross is normally NRL: Hunter, so a more precision match style scope serves me well.

That said, at only 8 lbs total, this build is still light enough for hunting. 

My old barrel was pretty constantly .80 MOA with my match handloads, but I also use premium components like Alpha brass, Hornady ELDM 140gr bullets, and Federal GGM SRP.

First rounds out of the Helix 6 were pretty good, even with my bulk reloads. After 50 rounds of getting to know the new barrel, I felt it was ready to start doing some real groups.


The best 5-shot group was .62 MOA, and as long as I kept the barrel on the cool side, I was able to repeat groups in the .6-.7 MOA consistently. Taking my time, the largest 5-shot group was only .86 MOA.

But that only held true if I allowed the barrel to cool off pretty often. 

One downside of carbon fiber barrels is that they don’t normally handle heat as well as their steel counterparts. This isn’t really Helix 6’s fault, it’s just how physics works. On the other hand, CF barrels also tend to cool off pretty quickly. Downtime between groups was never more than 2 minutes, and the barrel would be ambient temperature to the touch. 

Shooting while the barrel was hot, the groups got pretty wide.

After what was basically a 10-round mag dump, I shot a 5-shot group with the barrel toasty and got 1.52 MOA.

Allowing the barrel to cool off, then repeating a 5-round dump followed by a 5-shot precision group resulted in 1.50 MOA.

Both of the “hot” groups had the POI shift down and to the left in basically the exact same way.

Let the barrel cool again, and another .65 MOA group went down range easily.


CF barrels' strength is their lightweight nature, but their weakness is an uphill battle with heat. This isn’t surprising or unusual, it’s just how it is.

For a hunting barrel, the Helix 6 is pretty amazing. With a cool barrel, the groups are outstanding.

This is really how the barrel should be judged since this is what it is designed for. Taking a lightweight carbon fiber barrel and trying to shoot long strings of fire with it is like taking an F1 car overlanding. You’ll look cool, but you won’t get far.

The Helix 6 performs up to my expectations. Precise and accurate for the first 5 or 6 rounds, and starts to fall off when it gets hot.

A ~0.60 MOA barrel is a solid shooter.

Also, it is worth noting that I only put about 100 rounds through this barrel so far. While barrel break-in is a myth, it is fair to say that the muzzle velocity is still stabilizing as I go through the first 200-ish rounds. The groups tightening a bit more as I shoot the rifle wouldn't surprise me.


So, is the Helix 6 barrel worth it? I think that’s a tall order.

According to my scale, the Helix 6 barrel is only 8 ounces lighter than the OEM barrel. With the Helix 6 barrel costing a full $1,450, that basically doubles the price of the SIG Cross.

That said, the Cross isn’t known for having an amazing barrel. I think I got lucky in that my OEM barrel is a solid .80 MOA barrel with my handloads. A lot of people don’t get nearly as nice of an OEM barrel, and a Cross shooting in the 1-1.2 MOA isn’t uncommon for a lot of people.

If you have a Cross that shoots well to start with, I don’t think saving 8 ounces is worth the price tag of the Helix 6.

But if your Cross isn’t shooting that well, spending the extra money to get a really good barrel that is also carbon fiber might be totally worth it. And with that, Helix 6 is a solid option.


I’ll be honest: I’m not normally a huge carbon fiber fan. But Helix 6 gets my seal of approval for a solid barrel. If I’m looking for a CF barrel, they would be one of the few brands I’d trust to get it done right.

The price hurts, but top quality doesn’t come cheap. 

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  • Mike says:

    Can we assume your barrel was a 6.5 creedmoor before you upgraded the barrel?
    Saving 8oz is a nice option over factory
    In the pics I see two different scopes; at 8lbs is that with Maven?
    Thanks good article

    • David Lane says:

      Yes, it was 6.5 CM to start with. But the bolt face is the same for .308 Win and 6.5 CM.

      Yes, 8 Lb was with the Maven

      Thank you 🙂

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View Comments

  • Can we assume your barrel was a 6.5 creedmoor before you upgraded the barrel?
    Saving 8oz is a nice option over factory
    In the pics I see two different scopes; at 8lbs is that with Maven?
    Thanks good article

    • Yes, it was 6.5 CM to start with. But the bolt face is the same for .308 Win and 6.5 CM.

      Yes, 8 Lb was with the Maven

      Thank you :)

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