I must admit that I'm often confused on why this project has been delayed. Looking at the specs of the K9 Thunder on wikipedia, the barrel is 155mm/52 cal so that is one box ticked.
Well its a lot harder to tick those boxes than use of such language implies, there are also more unique things required by the Army that had to be developed plus work outside the SP gun contract to make it all work.
But the core of the reason the LAND 17 SP gun has been delayed is the Government wanting to save money. KMW pulled out of it ages ago but Samsung remains highly motivated to win this contract as it is an 'in' for a major Korean combat system into a 'western' force.
The delay at first was covered by 'risk management' and the K9 had to be shipped out to Australia and fire a few rounds just to prove it could and so on but when that was all done it was back to hurry up and wait until the new schedule rolled around. All because of the Government trying to keep the cash flow under control until the budget is back in the black.
So we have the ridiculous situation of a tender that went out in 2008 which was meant to see a contract signed by the end of 2009 turned into a four or more year offer definition process with only one motivated tenderer.