EAPS: The US Army’s New 50mm Cannon?

Over at AUSA 2018, General Dynamics showed off their Griffin III demonstrator vehicle, which was armed with, among other things, a new 50mm cannon. At first, I thought this was simply someone actually executing on the old 50mm Supershot idea, but this is only half true.

What’s carried over from the Supershot program is the basic cartridge shape1, i.e. that of a 35x228mm cartridge ‘necked out’ into a straight-walled case. The gun, which is basically a Bushmaster III with a new barrel and slightly revised feed system, is still externally driven. Nothing super new there. What is new is the goal.

50mm Supershot was designed to have a way to get a more powerful APFSDS round out of the 35mm cannon. A quick barrel change, add new rounds, and you could smash up a tougher Soviet IFV, since 50mm Supershot got you about as much propellant as a 40mm Bofors round, but in a smaller package. Of course, the Soviet Union is no more, and now they have much smaller armored forces. What they do have are precision guided munitions, UAVs, and the traditional giant artillery park.

The new Extended Area Protection System (EAPS–yeah, it’s a stupid name) worked to adapt modern technology and the capacious 50mm round to attack the problem of C-RAM (Counter Rockets, Artillery, and Mortars) as well as countering larger UAVs. What they’ve settled on is a Course Corrected Projectile, fired out of the 50mm gun, equipped with command guidance and a fragmentation warhead.

EAPS and its guided projectiles have passed some basic proof-of-concept testing. It remains to be seen how well the system will shake out. I kinda like the idea, and it’s a better reason than most to increase the autocannon caliber. I’m skeptical that it will work all that well in practice, but it’s at least a new idea.

As for the gun, we can extrapolate a little from the Bushmaster III. Still no word on the capacity of a mounted one yet.


  1. Though the devil lurks in the details. I have no idea if the old rounds would also fit in the chamber for the new gun. 

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