CMMG MK9 9mm Stripped AR-15 Lower Receiver

Manufactured by CMMG
SKU: 90CA2F3
MPN: 90CA2F3
Manufactured by CMMG
2 Reviews
No Longer Available
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Items that are regulated by the ATF have restrictions and requirements: 
โ€ขYour entire order will ship only to a Federal-Firearm License holder.
โ€ขPlease contact your local FFL prior to placing your order to ensure they are still accepting transfers.
โ€ขA copy of your order/invoice as well as the current FFL license for your local dealer must be emailed to



This CMMG AR-9 Dedicated 9mm Lower Receiver is designed for use with Colt pattern magazines. This is stripped lower includes some 9mm specification components pre-installed including ejector, bolt hold open, and feed ramp. These parts have been engineered by CMMG to work together in harmony to maximize the reliability and durability of your 9mm build.

  • Forged 7076-T6 Aluminum
  • Includes feed ramps, ejector, and extended bolt catch
  • 9mm caliber
  • Accepts standard 9mm colt pattern mags 
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Caliber Marking9mm Luger
FinishHardcoat Anodized
Receiver Material7075-T6 Aluminum
Trigger Pin DiameterMIL-SPEC .154

WARNING: This product can expose you to chemicals including lead, which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information, see

California Prop 65 warning

 WARNING: This product can expose you to chemicals, which are known to the State of California to cause Cancer and Reproductive Harm. For more information go to

Ratings & Reviews

2 reviews

  • 3 stars
  • 0 reviews
  • 2 stars
  • 0 reviews
  • 1 star
  • 0 reviews

Simply The Best!

by -

Built a 9mm rifle using this lower. After getting the tuning right with different buffer/spring combos, this gun is one of my favorites. If you want a Colt-style 9mm, this lower is the way to go. Why buy one of the adapters and a lower when you can have a quality dedicated lower? It's expensive, but you get what you pay for. I used the CMMG bolt, JP tuned and polished spring, and Spike's T3 buffer and it runs 115, 124, and 147 grain ammo 100%.

Ejector needed adjustment

by -

Put this lower together with a Right to Bear upper and BCG, a Bear Creek 7.5โ€ barrel, and used ASC mags. First shots had FTE issues. Hand cycling rounds barely ejected from the gun it at all. Noticed the ejector had brass on the inside (was skimming the casings instead of hitting the rim). Bent it slightly until it was noticeably pointing inward. Fired 100 rounds without further issue. -1 Star for not working out of the box. Itโ€™s an easy fix and in all truth, it could have been differences in tolerances from mixed parts.