The latest manufactured 106mm RCLR rounds can kill main battle tanks with full thickness of armor-including explosive reactive armor -not just the measly 2" that the 40mm can pierce only if struck at an unlikely 90 degree angle. The 106mm will effectively bust reinforced bunkers and totally demolish buildings. Australian Army 106mm RCLRs have the CLASS laser sighting system that extends its range to 1800 meters with 80% first-round hit probability at night against moving targets. The latest electronic sights are ready to mount on the M40A2 just as easily as the MK-19. Try to get this accuracy with the "garden-hose"-style firing pattern of the MK-19... you'll only alert the enemy to kill you with his large caliber cannon if he's in an Armored Fighting Vehicle (AFV). The MK-19 on HMMWVs in Somalia were only adequate enough to suppress the enemy and "break contact"; the Rangers wouldn't have been saved without allied Armored Fighting Vehicles on the scene (the same M113 type vehicles that we're making reefs out of) that were able to absorb the intense enemy fire that was not stopped by the Mk-19's best efforts.
If you want to ride around the battlefield in an unarmored, air-filled, rubber-tired land-locked (non-swimmable) HMMWV or LAV-III/IAV with just a grenade launcher and get clobbered by artillery fire or the typical Third World country 's Armored Fighting Vehicle with large caliber direct-fire cannon, be my guest--but don't offer such impotent ideas as solutions to our Airborne/light forces' urgent need for a battlefield dominating gun system. HMMWVs alone with only 40mm MK-19s are not capable of fulfilling the purpose of the 106mm RCLR: to win battles "hands-down" by overwhelming shock action and explosive effect against POINT TARGETS. Hard targets must be completely destroyed with one shot not peppered over time....What's going to happen to the MK-19 and its thin-skinned HMMWV the minute they get hit by a RPG? Or even a burst of heavy machine gun fire ?....... You don't trifle with an enemy strong point, you point, shoot and blast it to "smithereens", or else you're the one that gets destroyed. The Mk-19 is an automatic grenade launcher, not a main gun; it must fire continuously to achieve destructive effects: area suppression yes, shock action, no. While not ideal, if we mount both systems; a RCLR and an auto grenade launcher on every other armored HMMWV, you're making victory possible instead at best, tortured stalemate.
The current MK-19 is a development of the Vietnam war-era series of automatic grenade launchers and is just about as old "technologically" as the 106mm RCLRs still in use by U.S. Army SF (5th SFG in Desert Storm ). We must avoid "avante garde" moods that equate something "new" as automatically better; the current trend in military circles to emasculate firepower and opt for expensive, shiny black weapons with electronic gadgetry that make a lot of noise and look fashionable on Hollywood-movie HMMWVs, forgets the fact that war is for real weapons not play toys. In combat its what physically kills that counts, not what is easy -to-do or "fun to shoot" like the Mk-19.
One gun system is not adequate to defeat the increasingly hard targets of a rapidly urbanizing world, it will take a combination of gun systems on a survivable, fully terrain mobile platform that is air-deliverable, and can move into firing position even against enemy small arms fire. The 106mm RCLR is for blasting hard, PONT TARGETS, the 40mm MK-19 is for AREA TARGETS, the Javelin missile for main battle tanks and helicopters. Place all 3 weapons on an autocannon/RPG resistant applique' armored M113A3 armored fighting vehicle and you get gun-missile-auto grenade cannon-infantry synergism greater than parceling these systems out onto the Soldier's back, soft-skin HMMWVs or collecting dust in storage (where dozens of U.S. 106mm RCLRs are today). The lack of organic fire support in our light units is a life and death issue too serious to be viewed emotionally as either a sentiment for the old or avante garde' for the new: its about what works and doesn't work on the modern battlefield. The MK-19 as good as it is, will not by itself give us battle-winning shock action like an AFV-mounted 106mm, M3 84mm RAAWS ("Carl Gustav"), or M67 90mm RCLR can.
SFC Ernest Hoppe U.S. Army SF
