Summer Cleanout Sale!
Huge Savings On 2000+ Items From 200+ Brands - SHOP NOW

Summer Cleanout Sale!
Huge Savings On 2000+ Items From 200+ Brands - SHOP NOW

Daily Deal: MTM 250th Anniversary 5-Can Ammo Crate $49.99 $32.99- Get Yours! 

AR-15 MK4 Receiver Extension Kit
AR-15 MK4 Receiver Extension Kit
AR-15 MK4 Receiver Extension Kit
AR-15 MK4 Receiver Extension Kit
None
Sale Sale OFF

CMMG - AR-15 MK4 Receiver Extension Kit

1 Review
AR-15 MK4 Receiver Extension Kit
Brownells #
100037932
MFR #
55CA9D7
UPC
816422020676
$32.37 $38.08
Coupon Code
Purchase Limit Help

Out of Stock

NOTIFY ME WHEN IT'S BACK IN STOCK
Can we ship this to you? (US only)
{{restriction.odmShipCheckMessage}}

How To Buy Guns Online

International purchase information

Specifications
Material:
Aluminum
Color:
Matte Black
Buffer Tube Type:
Mil-Spec
Buttstock Fit:
Carbine
Make Model Fit:
AR-15.Universal;AR-308.Universal
Quantity:
1
Restriction
Gun Part Restrictions:
Yes
Prop 65 restriction:
Warning! Cancer and Reproductive Harm. Www.p65warnings.ca.gov
View US State Restrictions
Can we ship this to you? (US only)
{{restriction.odmShipCheckMessage}}

How To Buy Guns Online

International purchase information

What is the CMMG - AR-15 MK4 Receiver Extension Kit?
Mil-Spec 6-position adjustable Carbine Receiver Extension (buffer tube). Made from aluminum with a matte black hard coat anodized finish, accepts mil-spec pattern carbine length buttstocks or pistol braces.

See all of our AR15s and AR15 parts here.

Gun Part Restriction
Gun Parts have restricted shipping to CA.

Prop 65WARNING: Cancer & Reproductive Harm - www.P65Warnings.ca.gov

Please select a FFL Dealer
or
7 dealers near
Distance:
10miles
arrow-down
Sort by:
Nearest first
arrow-down
pin wrong
No dealers found

Please search by another zipcode to find the nearest dealer.

Close
Brownells Retail Store
Phone Call
Pin in
Clock
You must select required check box

Note:

Listed hours & fees are not guaranteed and subject to change. Please contact the dealer to confirm current hours & fees.
* Must accept required fields.
  • Pin in Brownells Featured Dealers

    Choosing a Brownells Featured Dealer is the fastest and easiest way to complete your purchase. Brownells Featured Dealers have agreed to perform FFL transfers on guns purchased online from Brownells. We have their necessary FFL information on file and your FFL order will ship directly to them once processed.

  • Pin in Standard Dealers

    Standard Dealers have not yet agreed to perform FFL transfers on guns purchased online from Brownells. If you choose a Standard Dealer, you are responsible for contacting that dealer and arranging for the dealer to submit a signed copy of an FFL and to give Brownells permission to ship the gun.

  • Pin in Not Available Dealers

    Not Available Dealers are dealers Brownells cannot ship guns to at this time. These dealers either do not meet our requirements for FFL transfers, or prefer to not perform transfers for guns purchased online from Brownells.

Switch view map
7 dealers near

Alternative products

Left Badge
Right Badge OFF  
5 Stars

200

300

Add on

Left Badge
Right Badge OFF  
5 Stars

200

300

AR-15 RECEIVER EXTENSION REVIEWS

5.0
1 Review
5 Stars
100%
4 Stars
0%
3 Stars
0%
2 Stars
0%
1 Stars
0%
5
Good buy
Quality product
by CAMILLO PRIOLE on June 28, 2026
Verified Purchase
Was this review helpful? 0
Customer Questions
0 Questions