The Army was working a program like this called Crusader.
Crusader was supposed to replace the M-109A6 Paladin 155mm self propeled artillery system. It was a self loading gun that reduced the crew to two. It was cancelled in 2004 by Rumsfeld for being to heavy. A year later United Defense who was absorbed by BAE Systems created the NLOS Cannon and Mortar systems using the same technology they used on Crusader. The NLOS was lighter and faster. In 2007 when I retired from the Marine Corps I was recruited by BAE Systems to work on the NLOS Cannon program as part of the test team at Yuma Proving Ground. This gun was awesome! It ran circles around the Paladin is side by side testing. It could out shoot and out run the Paladin on every test. We built and tested 5 guns by June of 2009, and were about to go into limited production at BAE’s facility in Oklahoma.
On 29 June 2009 we got the Stop Work Order from our bosses in Minnesota because the Obama admin cancelled the program.
6 years later the Army still doesn’t have a suitable replacement for the Paladin, and the technology for NLOS is sitting in a warehouse in Aberdeen MD just rusting away.
Wasn’t United Defense the outfit that came up with the M-8 AGS and the spinoff 120mm Thunderbolt?
Apparently UD didn’t payoff the right General (Shinseki) or the right President (Clinton).
What a shame, those were really sweet vehicles. I had my name on crosstraining to the M-8 because my enhanced NG Brigade was supposed to be getting them.