Expo Arms 5.56 NATO Chrome Lined AR-15 Barrel - GOV Profile -Mid Length - 16"

Manufactured by Expo Arms
SKU: XP-B-556-16-GOV-C
MPN: XP-B-556-16-GOV-C
Manufactured by Expo Arms
12 Reviews
$127.96 $159.95

Out of Stock

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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 16” model features a government contour with a mid-length gas system and .077” 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.

  • 16” Government profile chambered in 5.56 NATO
  • Mid-Length gas system with .077” 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 ContourGovernment
Barrel Length16
Barrel LiningChrome
Barrel Material4150 Chrome Moly Steel
BrandExpo Arms
Caliber Gauge5.56 NATO
Feed RampsM4
Gas Seat Diameter.750
Gas System LengthMid-Length
Thread Pattern1/2 X 28
Twist Rate1:7
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

12 reviews

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Great barrel

by -

Put about 125 rounds through it the first time out and could have shot all day.


by -

Well I'm shocked, and pleasantly so. Chrome lined and dimpled, which I did not expect for a barrel this price. Took it out yesterday, and with Federal M193 55gr, I'm getting about minute and a half. I shot 5 groups at a 100 yards after zero to see the accuracy, and not a single group went over 2", not using a rest just shooting off the bench. Brother I am more than happy with that for a 2Gun or 3Gun setup. For a cheaper barrel, I'm pretty stoked with it.

Nice Barrel


Barrel arrived in perfect condition. Fit and finish is flawless. Shot a 5 shot group less than 1MOA first time out with some random 55gr Sierra handloads I had made up for a different gun. This barrel shoots everything well. Some better than others. No regrets buying this barrel. Excellent.

Excellent barrel.

by -

This barrel will shoot. Excellent accuracy with a perfect fit and finish. Gas port is perfect diameter. Mine measured exactly .078" with pin gauges. I feel this barrel was an absolute bargain for the price. Would highly recommend to friends and family. Quality piece.

Great barrel at a good price!

by -

I needed a decent barrel for a build. I was pleasantly surprised with the Chrome lined Expo barrel. More accurate than I was expecting.
The finish was also great. I already have a few expo rails and parts on other rifles. Never had an issue with anything expo.

Expo Arms Combat Series 16" chrome lined barrel

by -

Primary Arms ships quick with tracking updates. Awesome! Barrel looks great. I will be testing it this weekend for accuracy. Nice fit into an Anderson upper. Had to tap it in the last 3/8" with a rubber mallet. Now to see how it compares to an SOLGW 16" middy for least picky about ammo and best overall groups. Winner gets a permanent home with me. So far every Expo Arms item I have purchased has been great!


by -

Bought this about a month ago and left a 4 star review based on a visual inspection and fitment to reciever and gas gas block.
Everything was great as expected. Took it to the range on Saturday andshot five 5-shot groups from 55 grain to 75 grain, 4 different brands. All regular off the shelf stuff to sight in and function test the gun. Shooting at 50 yards the best group was .365" and 3 groups were average .875, the largest was 1.2" but four of those were touching at .490". So yeah, it's a keeper. This barrel is fantastic for a "combat" barrel.


by -

I’ve gotten quite a few of these barrels for builds, never any issues and love the fact already dimpled! Always like my chrome lined barrels.

Holy Cow


First off I know expo is PA brand but there stuff is TOP OF THE LINE. This barrel is gassed PERFECT. I prefer phosphate finish on barrel and bcg and I'm running both and I can not believe the quality from this barrel and bcg. It's accurate and take my word I shot a nickel sized 4rnd group at 50 with a dot. I can not believe this EXPO stuff but damn 4 o clock ejection without a blue springco is just mint

Took a gamble and came out on top!

by -

This is fantastic for the price. Micro groove rifling, concentric crown, dimple for the gas block, chrome lined, and thick magnesium phosphate coating. I am very impressed with reliability and accuracy so far, all that's left is longevity!