Chrome-lined barrel options?

[ashooter]

I'm planning on building or buying another 14.5"-16" upper in the next few months and am looking for info on what my options are. I want to stick with a chrome-lined 4150 or CMV barrel for durability and stiffness (less zero shift with a suppressor). The catch is that the barrel needs to have the step behind the muzzle like an M4 barrel, so I can use an Ops Inc M4 collar on it. Other than that, I'm not married to the idea of an "M4 barrel".

I'm thinking the simplest option would be an LMT M4 upper, and the best option would be a BCM or Sabre M4 upper. BCM and Sabre seem to be unavailable, and have been for quite some time... Noveske's new "lightweight" barrel looks great, but looks like it would be incompatible with the Ops collar unless I pay for a custom contour, if that's even possible. Any other options?

Yeah, I know: too much time on my hands. :rolleyes:

[shark31]

CMMG would be another option.

[AR15barrels]

CMMG would be another option.

There HAVE been issues with the collar diameter.

Per dozens of COLT barrels I have measured, this step needs to be right at 0.700" in diameter.
If you get a barrel without this step, I can certainly put the step on it for you.

[ashooter]

CMMG would be another option.


I have a CMMG barrel on my old "beater" M4. It's been GREAT through maybe 4000 rds or so, and I'd just use it except for the permanently attached flash-hider it wears. Since this upper will be primarily shot suppressed, and there seem to be a lot of mixed reviews of CMMG's barrels (?'s about chamber dimensions, barrel steel etc), I am kinda shying away from them.

For the same money, I could have a BCM, if and when they become available.

[ashooter]

There HAVE been issues with the collar diameter.

Per dozens of COLT barrels I have measured, this step needs to be right at 0.700" in diameter.
If you get a barrel without this step, I can certainly put the step on it for you.


Thanks Randall, I'll keep that in mind!

Have the "issues" you've seen with the collar diameter been issues with out of spec barrels or out of spec collars?

[AR15barrels]

Have the "issues" you've seen with the collar diameter been issues with out of spec barrels or out of spec collars?

Out-of-spec collars on the barrel.
Usually oversized so anything that needs a specific 0.700" step may not fit.

Most items that slip on that collar actually have 0.003" to 0.007" of clearance added, but some barrels will measure as large as 0.720" at the collar.

For example, Smith Vortexes depend on that coller being there for the skirt to slide back over.
The Vortex skirt is 0.707" inside diameter IIRC.
I open up the rear of a Vortex before installing it on a barrel without a proper 0.700" collar.

[Bcm3087]

What about Noveske's N4 Light Carbine?