Expo Arms 16" 5.56 NATO AR-15 Barreled Upper Receiver - 15" M-LOK Handguard - A2 Flash Hider

Manufactured by Expo Arms
SKU: XP-P-556-16
MPN: XP-P-556-16
Manufactured by Expo Arms
7 Reviews

Out of Stock

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The Expo Arms AR-15 Barreled Upper Receiver offers a high-quality option for any build. The heart of this barreled upper is the Expo MIL-SPEC forged upper receiver assembly, upgraded with T-marks for repeatable optic mounting. The 16" barrel with a 5.56 NATO chamber and reliable mid-length gas system and is fully Nitrided. The 15" handguard features M-LOK slots on 7 surfaces providing plenty of space for your favorite accessories. The Expo Arms Barreled AR-15 Upper Receiver is the perfect choice for your next AR rifle build.

  • 7075-T6 forged aluminum MIL-SPEC upper
  • T-Marked
  • 16" barrel
  • Mid-Length Gas System
  • Nitride finished barrel
  • 1:7 Twist Rate
  • 15" Expo Arms M-LOK Handguard
  • A2 Flash Hider

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 CoatingSalt Bath Nitride
Barrel ContourSOCOM
Barrel Length16
Barrel LiningSalt Bath Nitride
Barrel Material41V50 Chrome Moly Vanadium Steel
BrandExpo Arms
Caliber Gauge5.56 NATO
FinishHardcoat Anodized
Gas System LengthMid-Length
Gas System TypeDirect Impingement
Handguard15 in M-LOK Rail
Muzzle DeviceA2 Flash Hider
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

7 reviews


PA comes through again!

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Another quality offering from PA 👍 fast shipping, packaged well and Expo Arms barrel, upper and handguard works well with my Aero lower. Quality product at a low price point

Solid Build, No Issues


Purchased through PA. Build seems solid and had no trouble zeroing it. No loose components or issues. All M-Lok components fit correctly and didn't touch the barrel.

One minor issue - the edge connecting the handguard to the upper can be a little sharp on the corner. Recommend hitting it with a dremel to round it off a little bit as it might cause some rubbing damage to gear.

Perfect fit, looks good


For the price I don’t know how you beat this upper. Fit perfectly, cosmetics top notch. I added a Expo Arms BCG and a Radian Raptor Lt charging handle. I’m diggin it!!

Solid upper


Great upper for the money. Added a micro best bcg, geissele charging handle, and a sfp 1-8 primary arms lpvo. Pushed it out to 600 yards no problem. The ejection port cover wouldn't open all the way because the handguard butted against the pin. I swapped it with a bcm cover assembly and that one worked fine.

Great upper!

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Fit all my needs to complete my AR build. Paired with my Ruger AR556 lower, this build is light and looking good!



Excellent for the money. If you catch them on sale buy a few and you won't be disappointed. Handguard is slim and has a very solid lockup. Will definitely be buying more!

Terrible accuracy

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The accuracy of the barrel is terrible with 2 different bcg's. I tried multiple types of 55grn, 62grn and some 75grn with lousy accuracy(2.5-3 moa @100yds). Unacceptable in my book! I should have stuck with Aero.

Thank you for taking the time to speak with me today. We are happy that we were able to get your exchange out to you and that you are no longer having accuracy issues with this product. Please do not hesitate to reach out if you have any questions.