The LMT Defense M203 Carbine Mounting Kit (LMT part no. L4B1) is a purpose-built hardware set that mounts a standard M203 grenade launcher to M4-type carbines. Manufactured by LMT Defense, the kit includes all the mounting hardware and a leaf sight assembly needed to integrate the launcher with a carbine-length AR platform. It’s scaled specifically for carbine-length barrels, distinct from LMT’s rifle-length kit built for full-size 20-inch-barrel rifles. This kit is the go-to solution for armorers and collectors outfitting a carbine-length host with a standard M203.

Key Specifications

• Fits: standard or M4-type carbines.
• Compatibility: standard M203 grenade launcher.
• Includes: leaf sight assembly for aiming.
• Style: Kit.
• Manufacturer: LMT Defense.

Frequently Asked Questions

Does this kit fit rifle-length AR platforms?
No. This is the carbine-length kit; LMT offers a separate rifle-length kit for 20-inch-barrel hosts.

Does the kit include a sight for the M203?
Yes, a leaf sight assembly is included for aiming the launcher once mounted.

Buy the LMT Defense M203 Carbine Mounting Kit

This LMT Defense mounting kit, part of our Gun Sights lineup, ships fast from our Lubbock, Texas gun shop — order online today.