We’re giving away a complete retro classic AR-15 and grenade launcher package, and you’re probably going to be the lucky winner, but just in case you’re not, you can add your very own M203 Grenade Launcher to a rifle you already have. Here, we’ll show you mounting options and exactly how to do it.

The installation process shown here is for a standard M16A2 20-inch rifle barrel with a .625” outside diameter. If that’s not your rifle, no worries, there are additional mounting options for M4 carbine barrels using a GI-type barrel nut at the rear. You buy the LMT M203 unit separately and then choose the right mounting kit option from the following choices.

M203 20-inch Mounting Kit with Leaf Sight

The “standard” original mount replaces the triangular handguard with black polymer versions containing internal aluminum heat shields. This model installs completely behind the A2-style gas block and front sight housing assembly and requires a rifle with the standard mil-spec barrel nut. The replacement handguard comes with the leaf sight. We’ll walk through the installation steps in detail in a minute.

M203 Carbine-style Mounting Kit with Leaf Sight

If you have a more recent M4-type rifle that uses or has a circular front cap and the .625″ outer diameter cutout just ahead of the gas block, then carbine-style mounting kit is what you need. Like the 20-inch barrel mounting kit, this one also comes with a leaf sight and replaces the whole handguard assembly.

Here's the carbine-length mounting kit. Note the replacement handguard and leaf sight.

Here’s the carbine-length mounting kit. Note the replacement handguard and leaf sight.

M203 Quick-Detach Mounting Bracket

This component is not a complete mounting kit but rather an add on to either of the rifle or carbine mounting kits that allows quick attach and detach of the launcher.

Read the rest: How to Install a M203 Grenade Launcher how to install LMT m203 grenade launcher