Abstract: An improved alignment guide for use in the MK-19 grenade launcher of the type having a body member with a centrally located slot defined therein extending to a bowl formed in the body member, the guide being characterized by a lack of upper and lower edge rails and having a single body aperture formed therein between its central screw aperture and the bowl, the body member around the bowl being approximately 0.25 inch thick with a thickened arm provided at the end of the body member beyond the bowl, such thickened arm being approximately 0.5 inch thick, such alignment guide having the same interface dimensions as that of the prior art alignment guide to allow the alignment guide of this invention to be engaged into the receiver of an MK-19 grenade launcher.