Insas was not a failure at all. Army wanted a 5.56 and we delivered it and the problems were solved later on. We used it almost 20 years now (more years to come). From where you will get a gun Rs-8000/-? at large numbers.
Now we are 'updating' the forces now and as per the current scenerio we need a gun which can use two rounds. (We are ahead of other forces like US army who still uses M4 only) as per the situation.
US army's standard assault rifle is the M-16. The M-4 is a carbine for CQB.