Sometimes it’s just fun to check out the biggest guns. And they don’t get much bigger or badder than this until you start measuring shells in inches.

While the Mk 19, a belt-fed grenade machine gun, is currently quite impressive, the Army wants more out of the weapons system. Specifically, it wants to make it more lethal, according to this post on

The goal is to improve the weapon’s muzzle velocity, cyclic rate, reliability, ease of assembly, and accuracy. Basically they want an all-around improved Mk 19.

The story says the Army is “pursuing this laundry list of objectives separately, with plans to later combine them into one upgrade package. Testing is expected in fiscal 2017, which starts October 1, with fielding possible the next year.”

The Mk19 has a range of about 2.2 km for an area hit, and about 1,500 meters for a more refined target. The tripod-mounted 78-pound weapon fires 40mm grenade rounds from a belt usually holding 32 or 48 grenades each. And it can fire those grenades at a rate of more than 325 rounds per minute, with a sustained rate of 40 rounds per minute, and rapid-fire rate of 60 per minute. The first version of the Mk19 was first deployed in Vietnam in 1968 and has been improved since.


“Each improvement is at a different stage of development,” said Peter Rowland, spokesperson for Project Manager Soldier Weapons. “The Army is planning to produce and field the upgrade as one kit. This will allow for efficiencies in scheduling and application of improvements at one time in lieu of separate efforts.”

And here’s that itemized laundry list that describes specifically how each challenge will be met:

  • A new barrel to provide less resistance, thus improving muzzle velocity (the barrel is a smoothbore, so the less friction there is on the way out, the more velocity the round retains.

  • An improved profile for the vertical cam to reduce the force needed to charge the weapon by 20-30 pounds; that will increase the cyclic rate

  • Redesigning the round-positioning block to decrease frequency of misfires, thus enhancing reliability.

  • A new cocking cam and lever design to provide a double-benefit: increased durability and shortened re-assembly time after maintenance.

  • Updated mechanical sight to aid accuracy, utilizing up to date ammunition ballistic data.