Does the CMMG MK4 .223 Remington AR Lower work with the CMMG 5.56?

CMMG MK4 .223 Remington AR Lower, Black - 55CA102AB

Lower Receiver

CMMG MK4 .223 Remington AR Lower

from $100.02

CMMG 5.56 Complete Bolt Carrier Group, Black - 55BA419

Bolt Carrier Group

CMMG 5.56

from $117.99

CMMG lower and CMMG bolt carrier group compatibility

Yes, they fit

The CMMG MK4 .223 Remington AR Lower works with the CMMG 5.56. Our compatibility rules found no conflict between them.

This exact setup is in a real GunPartPicker build.

Counted from real GunPartPicker builds: parts lists people put together while planning to buy.

Checked by the same rules the AR builder runs on every part you add: caliber, frame size, receiver pattern, thread pitch and gas length.

Fit is judged from the specs retailers list, which can be missing or wrong. Confirm with the manufacturer before you buy, and have a qualified gunsmith check any build before you fire it.

How often builders pair the CMMG lower and CMMG bolt carrier group

Backed by thousands of qualified builds that have both a lower and a bolt carrier group.

Bolt Carrier Groups builders put on the CMMG MK4 .223 Remington AR Lower

Share of builds with the CMMG MK4 .223 Remington AR Lower and any bolt carrier group

Lower Receivers builders put under the CMMG 5.56

Share of builds with the CMMG 5.56 and any lower

  • CMMG MK4 .223 Remington AR Lower

    Of lower picks
    0.3%
    Median paid
    $99

  • CMMG 5.56

    Of bolt carrier group picks
    0.2%
    Median paid
    $128
How we count ⌄

These shares come from GunPartPicker's build data: real parts lists people put together while planning a purchase, not sales or surveys. A build counts a part only when it is the final pick for its slot, so parts that were swapped out never count. Fit never comes from these numbers; it comes from our compatibility rules alone.

Frequently built with the CMMG lower and CMMG bolt carrier group

The part builders pick most often in each slot alongside these two, checked against both. Parts that conflict are left out.

Stock & Brace

Trigger

Light

Charging Handle

Upper Receiver

Gas Block

Pistol Grip

Muzzle Device

Handguard

CMMG MK4 .223 Remington AR vs CMMG 5.56: specs and prices

CMMG MK4 .223 Remington ARCMMG 5.56
Best price$100.02 at Classic Firearms$117.99 at Ammunition Depot
Stores3 of 7 in stock5 of 7 in stock
AssemblyStrippedn/a
PlatformAR-15n/a
Caliber5.56 NATOn/a
FinishCerakoteNitride
ColorBlackn/a
Cartridgen/a5.56 NATO

Both for $218.01 at today's best prices.

Today's best prices and 90 day price history

Every store we track for each part, cheapest in stock first. Prices are checked through the day.

CMMG MK4 .223 Remington AR Lower

CMMG 5.56

Price history, last 90 days

  • CMMG MK4 .223 Remington AR Lower: lowest $94.69 on Jul 15, highest $126.99 on Jul 11 over the last 90 days.
  • CMMG 5.56: lowest $128.36 on Oct 3, highest $174.95 on Jul 6 over the last 90 days.

Bolt Carrier Groups frequently paired with the CMMG MK4 .223 Remington AR Lower

Most picked next to it in real builds. Only parts our rules say fit the CMMG MK4 .223 Remington AR Lower are listed.

Lower Receivers frequently paired with the CMMG 5.56

Most picked next to it in real builds. Only parts our rules say fit the CMMG 5.56 are listed.