Free Shipping on Orders Over $99 with Coupon Code: FREESHIP for lower 48 states in the U.S.*.  No in-store services, please stay in the car for curbside pickup. Call 562-287-8918, we will bring the items out for you.

JBU Reinforced M4A1 Outer Barrel Set - w/ 363mm M4A1 Inner Barrel

SKU: ACC-SDJA18 JBUOut of stock


JBU Reinforced M4A1 Outer Barrel Set - w/ 363mm M4A1 Inner Barrel

This outer barrel set is crafted from aircraft grade aluminum and serves as a perfect upgrade part. This set comes with an M4A1 outer barrel and tight bore inner barrel that measures 6.03mm in internal diameter, providing maximum accuracy and increased FPS. Because these barrels are precision crafted, only high quality, precision grade BBs should be used with this inner barrel. Professional installation is recommended for anyone unfamiliar with installing a new inner barrel. The super slick performance finish strengthens and protects these barrels, while reducing friction (conserves velocity & back spin). This simple upgrade kit will result in improved accuracy and is perfect for converting M16s into M4 style AEGs or replacing old multi-piece outer barrels.

Note: This outer barrel set is ready to use right out of the box, though professional installation is recommended/may be required. Please use only ultra high-quality precision seamless BBs in your gun after installing this barrel, as inferior grade BBs (i.e. BBs from sporting goods stores) WILL jam inside this barrel.

In the Box

M4A1 outer barrel

tight bore inner barrel


Inner Barrel Diameter 6.03mm
Inner Barrel Length 363mm
Outer Barrel Type M4A1
Barrel Construction Aluminum
AEG Compatibility M4A1 AEGs

California Proposition 65 Warning: Cancer and Reproductive Harm -

JBU Reinforced M4A1 Outer Barrel Set - w/ 363mm M4A1 Inner Barrel Quick Compare

This feature is currently unavailable.

Rate & Write a Review


Rate & Write a Review

Product name Q&A


Click on link to download:

Connect with us.