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Rainier Arms, LLC

Rainier Arms AR-15 Base Piston .223/5.56MM - 14.5

Rainier Arms AR-15 Base Piston .223/5.56MM - 14.5
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Availability: Out of stock




Our Piston Series are built in collaboration with Adams Arms Piston Kits. The 5.56 Midlength Base 14.5" Upper is a standard mil-spec upper that incorporates the patented Adams Arms technology. The midlength piston system will give you the benefits of a longer forearm by giving the user a longer, more ergonomic grip, a longer sight radius between the front and the rear sight for quicker sight acquisition and less felt recoil. The piston system parts and the barrel have been treated with salt nitride Meloniting process making them harder and more corrosive resistant than hard chrome. Our Piston Series system allows you to have an upper that will run cleaner, cooler, and longer than any other AR upper you own.


  • Rainier Arms Forged Mil Spec Upper Receiver
  • Voodoo Barrel: 5.56mm NATO 14.5" Government Contour
  • Barrel Material: 4150 Chrome Moly Vanadium Steel
  • 1:7 Twist
  • Muzzle Thread Pattern: 1/2"-28
  • Barrel Finish: QPQ Melonite / Black Nitride
  • M4 Feed Ramps
  • Bolt Carrier: 1-Piece w/Integral Piston Strike Face
  • MP Tested Bolt
  • Gas System Length: Mid, Short Stroke Piston Operated
  • Handguard: 2-Piece Polymer, Mid-Length


Additional Info

Additional Info

SKU RA1405
Manufacturer Rainier Arms, LLC
Finish No
Barrel Length No
Caliber No
Configuration No
Option No
Gas Length No
Height No
Rail Length No
Mount No
Profile No
Reticle No
Co Witness No
Size No



Feel free to ask us any question regarding this product.