Can this upper use both .223/5.56 ammo?

Name: CMMG MK4 T .223 REM/5.56 NATO 16" 4140 Steel Threaded Black
Brand: CMMG
SKU: 96783
Availability: OutOfStock

CMMG's website says it's good for 5.56, and if it's okay with that, .223 is perfectly safe.

The two cartridge cases are identical but the way the chambers are cut (the leade) and the way the pressures are measured are different. The .223 is safe in the 5.56 chamber but the 5.56 is not safe in the .223 chamber. Your upper will shoot either.

Yes this upper is interchangeable with both 223 and 5.56

Great question remember 5.56 is a more powerful ammo. If the upper does not say 5.56 I would not recommend you using 5.56 it's best if you just use .223 unless other wise stated. But this upper seems to be only .223

CMMG's website says it's good for 5.56, and if it's okay with that, .223 is perfectly safe.

BudsGunShop.com uses cookies to ensure you get the best experience. Details can be found in our Privacy Notice.

Got It!

Suggest Edit

CMMG MK4 T .223 REM/5.56 NATO 16" 4140 Steel Threaded Black

Reviews| 1 Questions & Answers

Model: 55BC76A

Condition: Factory New

Bud's Item Number: 96783

UPC: 815835015866

MFG: CMMG

Questions & Answers (1) Reviews 0 out of 5

CMMG MK4 T .223 REM/5.56 NATO 16 4140 Steel Threaded Black

**Mouse over image above to zoom any area, or click on image to zoom the entire image.

When modularity, affordability, and quality are all important the Mk4 T is the upper of choice. The Mk4 T introduces CMMG's RKM series of KeyMod free float hand guards and a nitrided 4140 CrMo steel barrel in a medium taper profile.

OUT OF STOCK

Add to Wishlist

Notify Me When Available

Add To Wish List

Ask the Community

Retail Store Availability

For our firearm inventory only. Please contact or visit our retail stores for ammo and accessory prices and availability.

Questions & Answers

Q: Can this upper use both .223/5.56 ammo?
Answered

Asked 05/08/2017 20:23 by Hans A

A:

The two cartridge cases are identical but the way the chambers are cut (the leade) and the way the pressures are measured are different. The .223 is safe in the 5.56 chamber but the 5.56 is not safe in the .223 chamber. Your upper will shoot either.
See 3 more answers |

4,581,265 Customers Since 2003

1,987 Currently Online

Receive Money Saving Offers

Enter your email address to receive our best deals and other store updates.

Conditions of Use • Privacy Notice

Model 55BC76A	Condition Factory New
Bud's Item # 96783	UPC 815835015866
Manufacturer CMMG

CMMG MK4 T .223 REM/5.56 NATO 16" 4140 Steel Threaded Black

Questions & Answers

Q: Can this upper use both .223/5.56 ammo?

Receive Money Saving Offers

Catalog

Information

Partners

Recommended For You

Recently Viewed Products

Shopping Cart

Wish List

Please log in to view your wish list.

CMMG MK4 T .223 REM/5.56 NATO 16" 4140 Steel Threaded Black

Locate FFL

FFL Search

Search Results

Dealer Info

Modal title

Suggest Edit

Description

(0 Reviews)

Questions & Answers (1 Questions)

Questions & Answers

Q: Can this upper use both .223/5.56 ammo?

Product Videos

Receive Money Saving Offers

Catalog

Information

Partners

Recommended For You

Recently Viewed Products

Shopping Cart

Wish List

Please log in to view your wish list.