A great value! Two military manuals combine into one book. If you purchase both books separate you will pay more for the books plus shipping cost. .50 cal. provides technical information, training techniques, and guidance on the caliber .50 HB machine gun, M2. This publication provides technical information on and training and combat techniques for the M203 grenade launcher. Intended users include leaders and designated grenadiers, who will use this information to successfully integrate the M203 into their combat operations. This manual discusses gunnery training and train-the-trainer, and it includes an appendix on the 40-mm grenade launcher, M79.