Shop by Category

  • Accessories
  • Books & Manuals
  • Firearms
  • Magazines
  • Pistol Parts
  • Tools
  • Rifle Parts

    • Shop by Brand

  • Colt
  • Magpul
  • AU
  • Blue Force Gear
  • MaTech
  • Simunition
  • Viking Tactics
  • View all Brands
  • Colt M4/AR15 Receiver Extension Castle Nut

    • Colt M4/AR15 Receiver Extension Castle Nut

    Colt

    $9.95
    (31 reviews) Write a Review
    SKU:
    9390020
    Adding to cart… category.add_cart_announcement

    Product Description

    Factory Colt receiver extension castle nut for M4/AR15 type rifles.

    Product Videos

    Custom Field

    Product Reviews

    Write a Review

    31 Reviews Hide Reviews Show Reviews

    • 5
      Colt Receiver Extension Castle Nut

      Posted by Michael Wiseman on 2nd Apr 2019

      My Colt castle nut was shipped fast and is typical Colt quality. AU is my go to for Colt products.

    • 5
      Colt quality, great price

      Posted by Mark on 13th Mar 2019

      High quality mil-spec part. A.U. Great company.

    • 5
      First Purchase

      Posted by Randy Ciuros on 5th Jan 2019

      I needed an extra castle nut, preferably Colt brand, and Arms Unlimited had it at the best price, with free shipping to boot.

    • 5
      Colt Parts

      Posted by Thomas R Griffith on 25th Dec 2018

      Always top notch parts, AU always efficient with fast service.

    • 5
      Colt M4/AR15 Receiver Extension Castle Nut

      Posted by Marty on 19th Nov 2018

      AU sells authentic Colt parts and the Colt M4 Receiver Extension Castle nut is no exception. Castle nut was brand new. The exceptional things about AU are their customer service, best prices on Colt products, fast shipping and no tax!

    • 5
      More Colt parts.

      Posted by Eric McKeown on 10th Jul 2018

      Nice to be able to buy individual lower parts with free shipping.

    • 5
      Great for a AR build

      Posted by Ed W on 9th Jul 2018

      I order this castle nut along with a Colts lower parts kit to complete a Colt lower receiver build that I'm working on. Fast shipping and good price from Armsunlimited.

    • 5
      Exactly what I needed

      Posted by Garrett Schmidt on 11th May 2018

      Fast shipping, product was perfect.

    • 5
      Colt M4/AR15 Receiver Extension Castle Nut

      Posted by John Gilbarty on 28th Apr 2018

      Super Service, Excellent Product, Great Prices/

    Recommended