LMT Monolithic 5.56x45 NATO 12.5" Mid Length Bbl Black

Name: LMT Monolithic 5.56x45 NATO 12.5" Mid Length Bbl Black
Brand: LMT Defense
Availability: InStock

LMT Defense · Barrels

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LMT Monolithic 5.56x45 NATO 12.5" Mid Length Bbl Black

Best price

$554.40at Brownells

In stock Lowest in 30 dayschecked Nov 13, 2026

Buy at Brownells

Compare 5 stores

Fits and works with

Caliber: 5.56 / .223 · Shop matching ammo
Bolt: Standard AR-15 (5.56 / 300 BLK / .350 Legend) · Bolt carrier groups
Gas system: Mid-length · Handguards
Barrel length: 12.5" · Handguards

Specifications

Manufacturer: LMT Defense
Color: Black
Platform: AR-15
Caliber: 5.56 mm NATO
Gas system: Mid
Barrel length: 12.5"

Where to buy

Store	Price	Availability	Buy
Brownells Best price 17.76% off · ends Nov 15 · exclusions apply	$554.40checked Nov 13, 2026	In stock	Buy at Brownells
Palmetto State Armory	$538.20checked Oct 12, 2026	Check store	Buy at Palmetto State Armory
GrabAGun	$599.99checked Nov 13, 2026	Check store	Buy at GrabAGun
Battlehawk Armory	$616.00checked Nov 13, 2026	Check store	Buy at Battlehawk Armory
Ammunition Depot	$554.40checked Oct 13, 2026	Out of stock	Buy at Ammunition Depot

Prices and availability change often, so confirm on the store's site before you buy. We may earn a commission from these links.

Price history

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Lowest in-stock price in the last 30 days: $554.40 at Brownells. Dashed line = out of stock. Tracking since Sep 27, 2026.

Show the prices as a table

Store	Latest	Lowest	Highest
Ammunition Depot	—	$554.40	$554.40
Battlehawk Armory	$616.00	$616.00	$616.00
Brownells	$554.40	$554.40	$554.40
GrabAGun	$599.99	$599.99	$599.99
Palmetto State Armory	—	$538.20	$538.20

Since Sep 27, 2026.

About this part

The LMT Monolithic 5.56x45 NATO 12.5" Mid Length Bbl Black is a 12.5" 5.56 / .223 barrel from LMT Defense with a mid-length gas system. It's sold by 5 stores (1 in stock), from $538.20 to $616.00. The lowest in-stock price in the last 30 days was $554.40 at Brownells.

From the manufacturer

LMT MONOLITHIC 5.56X45 NATO RIFLE BARREL Designed for the LMT monolithic receiver, this barrel utilizes a low profile gas block, straight gas tube, and A2 birdcage for reduced flash. The barrel is coated and cryogenically treated for long term durability. AVAILABLE OPTIONS: 10.5a ^2 Chrome Lined 5.56A-45 (.223) 1:7a ^2 RH twist barrel 11.5a ^2 Chrome Lined 5.56A-45 (.223) 1:7a ^2 RH twist barrel 12.5a ^2 Chrome Lined 5.56A-45 (.223) 1:7a ^2 RH twist barrel 14.5a ^2 Chrome Lined 5.56A-45 (.223) 1:7a ^2 RH twist barrel 16a ^2 Chrome Lined 5.56A-45 (.223) 1:7a ^2 RH twist barrel 20a ^2 C Mfg: Lmt Defense