CM4 5.56 Forged Receiver Set

Typically Processes/Ships Within 5 days from receiving FFL Copy - Custom Cerakote Lead Times Vary (See Disclaimer Below)
(8 reviews) Write a Review


MIL-Spec inner dimension measures at 1.000 -0.0/+0.002"

Thermal Fit inner dimension measures at .997 -0.0/+0.001" and requires the application of heat in order to provide a solid mate to the recommended barrel extension.  By heat we mean more than granny's hair dryer.

-For Use with M4 Barrel extensions
-Assembled Upper Receivers come with ejection port cover and forward assist installed



**FFL Required Before Shipping. Please have your dealer email their license to and have them reference your name/order number. 

No we do NOT accept fax as we live in the modern world and we also do NOT accept carrier pigeon. **


*** We recommend gunsmith installation for all of our parts.  We cannot warranty items damaged by improper installation.


Custom Cerakote Disclaimer:

Custom Cerakote is completed per order.  Our Cerakote room runs one color at a time so your ship date will be subject to the color rotaion at the time the order is placed.  You will receive an email confirmation once the item has actually been packaged to ship.

Cerakote items are not guaranteed to match separate batches or Cerakote completed by outside parties.  While we strive to keep our mix uniformed for our own products, we can't say for certain what Walter and Jesse cooked up in their lab out in Albuquerque.

Forged 7075-T6 Aircraft Grade Aluminum
Hardcoat Anodized per MIL-A-8625F, Type III, Class 2


  • 5
    Great set.

    Swapped my PSA set for this one and was super happy. I read reviews earlier discussing how tight the set was and would verify it’s true. It has a small amount of play, but it has a placement for a tension set screw to remove any movement. Awesome set!

  • 5

    Bought this forged receiver set as part of a SDM rifle. Impressed with the fit and quality of this receiver set. Would definitely purchase again and recommend to my friends.

  • 5
    CM4 Receiver set

    Just got these receiver sets (2) so I haven't had time to assemble them yet. Quality of machining and anodizing is excellent and lower to upper fit is tight with no slop. Order was handled in a timely fashion as an FFL was involved. No complaints with Centurion from me!

  • 5
    Beautifully machined

    Well made set.

  • 5
    Best Quality for an Unbeatable Price

    You really get more for your money with these receivers. All of mine gauged good with SOTAR gauges. The finish is very nice and matching between the uppers and lowers (for those that place an importance on that), the fit between the upper and lower perfect on my sets (not too loose or too tight), and the uppers are slightly “undersized” at the opening for the barrel for a tight fit. So a torch may be necessary to heat up the upper to get the barrel extension fully seated. It’s amazing at the quality you get for the price you pay. Centurion is truly a top tier brand at a mid tier price. I can’t recommend these receiver sets, or the company, enough. HIGHLY recommend to anyone looking for parts to buy with confidence from Centurion.

  • 5

    Absolutely fantastic product and even better people standing behind this company.

  • 5
    Awesome set

    The quality of these sets is next to none. Some of the coolest people in the game. If your on edge about buying take my word for it its well well worth it.

    Thanks guys!

  • 5
    Absolutely gorgeous

    Absolutely gorgeous ano. Tolerances that are as tight as you'd ever want. On top of an amazing company run by genuinely great people. You can't go wrong with centurion. I would and have purchased again.