User Ratings
No ratings yet
Be the first to review this product
Replacement MPX Gen2 barrel, 9mm Cal-X Kit Barrel CALX-MPX-4B-9-G2; 4.5 in (114.3 mm) length; Black Nitride finish; Steel construction. Fits MPX Gen2 platform. Includes Cal-X Kit Barrel CALX-MPX-4B-9-G2.
Specifications
- Manufacturer:
- Sig Sauer
- Category:
- barrel
- Caliber:
- 9mm Luger
- Platforms:
- AR-9
- Weight:
- 24.56 oz (1.53 lbs)
- Length:
- 4.5"
- Estimated velocity:
- 735-1,180 fps
- UPC:
- 798681555062
- MPN:
- CALXMPX4B9G2
- Required Component:
- Yes
Estimate only. Based on caliber + barrel length bucket. View details
Parts Cabinet
Track parts you own or plan to buy.
Where to Buy
Have one to sell?
Sponsored
MantisX
The smart way to train your AR build
Built your rifle — now train it. BlackBeardX installs in minutes and turns your AR into a full dry fire system with smart feedback on every pull.
Shop BlackBeardXPrice History
Current
$634.25
Lowest
$616.22
Highest
$702.81
Price Alert
Sign in to save a target price and receive an email when this component drops.
Sign In to Set AlertWhat's Included in this Bundle
Similar Products
Daniel Defense 16in 5.56mm NATO Carbine Length M4 Profile Barrel 07-075-08174-018
Daniel Defense
$289.99
Faxon Duty Series AR-15 Barrel 5.56x45mm NATO 10.5 Pencil Contour 1:8 Twist Black Nitride
Faxon Firearms
$132.40
14.5-inch 5.56 Government Profile Midlength AR 15 Barrel, Modern Series (OEM)
Ballistic Advantage
$170.00
Criterion Barrels Core AR-15 Barrel 223 Wylde 14.5" Mid-Length Chrome-Lined 1:8" Twist Black
Criterion Barrels Inc
$313.49
Criterion Barrels CORE 223 Wylde Carbine AR-15 Barrel 11.5in
Criterion Barrels Inc
$313.49
LMT Defense Chrome Lined Mid-Length Twist Barrel 5.56x45mm/.22 Cal 16" Fits LMT Defense L7S1A, Black
LMT
$472.99
Daniel Defense AR-15 5.56 NATO Barrel 11.5in Government Contour 1:7 Twist Phosphate
Daniel Defense
$296.99
Geissele CHF 5.56 NATO 14.5in 1:7 1/2x28 Chrome-Lined Taper Profile Barrel
Geissele Automatics
$287.00
Builds Using This Part
No builds yet — be the first to use this part.
Related Guides
Guide
5.56 NATO, .223 Remington, and .223 Wylde: Chamber Differences Explained
A technical breakdown of the differences between 5.56 NATO, .223 Remington, and .223 Wylde chambers — what each accepts safely, and how to choose for your build.
5 min read
Guide
The AK Platform: Core Design, Strengths, and Builder Tradeoffs
A practical AK overview covering operating system basics, parts ecosystem realities, and where the AK platform shines compared to AR-pattern rifles.
8 min read
Guide
.308 Win vs. 6.5 Creedmoor for AR-10 Builds
A technical comparison of .308 Winchester and 6.5 Creedmoor for AR-10 platform builds — covering ballistics, recoil, parts availability, and which cartridge fits which use case.
5 min read