Expo Arms 5.56 NATO Chrome Lined AR-15 Barrel - SOCOM Profile - Carbine Length - 11.5"

Manufactured by Expo Arms
SKU: XP-B-556-115-SOC-C
MPN: XP-B-556-115-SOC-C
Manufactured by Expo Arms
22 Reviews

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The Expo Arms AR-15 Barrels are designed to give you a premium barrel at an affordable cost. This AR barrel is made from Mil-Spec 11595E certified 4150 steel and features a chrome lined bore to withstand high temperatures for a long barrel life. This 11.5” model features a SOCOM profile with a carbine gas system and .070” port diameter for reliable function. Additionally, the .750 gas seat diameter is dimpled for securely attaching set screw gas blocks. The 1:7 twist rate is optimal for heavier 62 grain ammunition and the muzzle is threaded 1/2x28 for your favorite 5.56 muzzle device. The entire 5.56 Barrel is Phosphate coated for corrosion resistance and oil absorption. If you are looking for a combat ready barrel that provides exceptional accuracy and reliability, you can’t go wrong with an Expo Arms M4 barrel.

  • 11.5” SOCOM profile chambered in 5.56 NATO
  • Carbine gas system with .070” port diameter
  • .750” dimpled gas block shelf
  • Made from Mil-Spec 11595E 4150 steel
  • Chrome lined bore with Phosphate outer finish
  • 1:7 twist rate and 1/2x28 muzzle thread
  • M4 feed ramps

Expo Arms offers top-quality MIL-SPEC AR-15 components at rock bottom prices. Made in the U.S.A. and covered by Expo’s Limited Lifetime Warranty against manufacturer defects, material or workmanship problems, and even normal wear and tear.
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Barrel CoatingManganese Phosphate
Barrel ContourSOCOM
Barrel Length11.5
Barrel LiningChrome
BrandExpo Arms
Caliber Gauge5.56 NATO
Gas Seat Diameter.750
Gas System LengthCarbine
California Prop 65 warning

 WARNING: This product can expose you to chemicals, which are known to the State of California to cause Cancer and Reproductive Harm. For more information go to www.P65Warnings.ca.gov.

Ratings & Reviews

22 reviews

  • 3 stars
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Awesome barrel for the money

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Awesome barrel for the money In my opinion! Made a pistol build for home defense and used this barrel! Ran some federal 556 55gr, PPU 223 75gr match bthp, and frontier 556 75gr match bthp with no problems! Limited range at the time 17yds! Barrel took about 15 rounds to break in and seemed to like the frontier the best but the brands were good with no malfunctions! First time using the bear creek arsenal bcg too seemed to work fine! Need to get out to 25-50 yds!

If you're on the fence about it, G E T I T


Honestly one of the best barrels i've ever had. Took 20 or so rounds to break this bad boy in but after that it was smooth as butter. After a 36 yard zero i rang steel out to 200 yards no issue.

I think it is great..

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So I have two of these. One has been running on a pistol build for a couple months now. Works great with quite literally zero issues. I just recently ordered a second for my father in law. Assembled it, took it out and zeroed it. We were using a direct thread suppressor. About a mag in we couldn’t even hit paper. Then we found out why... F**** baffle strikes. Now I do not think it is the barrel as I used the same suppressor on my AR with the same barrel but I am not sure. I’ve check and rechecked the concentricity of the threads and it’s within .004 which is superb in my opinion. So I don’t know what is going on. Without a suppressor it is a tack driver.

Accurate and quality piece


Very accurate and quality made barrel. Machining is nice and phosphate coating is thick and even.

Super shorty!


Great looking barrel, shoots even better. 5 round groups at 100 typically 1.5" ,sometimes under, with Hornady Frontier 55 grain hpbt match and 1-8 scope. With break in, and the right ammo, possibly sub moa capable.

Very satisfied!


Got this barrel as a hold over until I could find a higher end barrel i was looking for. Took this barrel out and was extremely surprised at the accuracy. Zeroed at 50. Was playing around out too 100 and was holding just under 2 moa with m855. Couldn't have been more pleased!!!

excellent stuff


The quality of this barrel is outstanding. Chamber finish looks great and measures out perfect and gas port size is ideal. Accurate with 75, 62 and 55 grain hand loads but cycles steel case just fine also. I also recently purchased a colt 11.5 and its a nice unit but this expo is just better. Im not sure who actually manufactures this barrel but i wish i had of bought 2 of them while i had the chance.

Love this barrel!


I have been very pleased with this barrel. I was doing an HRT clone build and was thrilled when I found this barrel that had all the specs I was looking for. SOCOM profile, chrome lined, 11.5" and only $100! It was a no brainer. Had some cycling issues at first but discovered eventually that the Expo Arms gas tube(s) that I bought with this barrel were out of spec so I do NOT recommend those. But once I got a proper gas tube installed, the barrel runs great! I'm happy with the accuracy I'm getting which is usually around 2 moa or under. And I'm very pleased to report that this barrel is not horribly overgassed like many other barrel in this price range. I'm using a standard carbine spring and a heavy buffer and it cycles steel and brass, suppressed or unsuppressed. So I have really enjoyed this barrel and especially at this price point. I have zero complaints or issues with it. 👍👍

USMC veteran review

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Pleasantly surprised with this barrel. I used it on a SBR that I had been slowly building while waiting on the stamp. Very consistent under fire, and the chrome lining helps with accuracy and barrel life. I added a 12” MWI rail and Breek Arms blast cap and it looks amazing as part of it he upper. Don’t hesitate, this barrel is good to go. Be safe and God bless. Semper Fi.

Gave it a shot!


Well first of all, let me say this is from a very particular point of view. An FN barrel was previously my “cheapest” barrel. I have way too many years of service to build anything short of bullet proof. Saw this was chrome lined, 1-7 and pre-dimpled so I figured I’d give it an honest try. Assembled easy replacing the 16” FN barrel. Chrome was not as thick as my FN, DD, Colt or Criterion barrels but that is to be expected for the price. Initial cleaning felt like the first 3 inches had some tight spots. No biggy. Took it out to the range and it ran like a champ. Zero feeding issues, kept cool, accurate for an 11.5 and supported the suppressor extremely well. Groups hovered near the same as the previous FN Barrel. Very pleased!