Whether the INSAS will kill or maim is the question of range i.e. how far the person was when he was hit.
Why should it maim and not kill?
The reason is not hard to find.
If a man is killed, it is Finito. Sympathy, a cremation at a later stage after the battle, and no more. Maybe, a medal!
Now, if a man is maimed. He is howling. Bad for the morale as it affects those next to him and demoralises. He has to be attended to or else again bad for the morale. The ones to attend means less ‘bayonet strength’ since they are looking after the man and not involved in the battle. That much easier for the party that maimed.
This wounded man will have to be evacuated (If he were dead, it could be attended to later). Again depleting bayonet strength! If he is not attended to and not evacuated, he will howl and it will be real demoralising and none would like to believe that this would be his fate if hit!
When the hospital are full of maimed chaps and the do gooders and TV come to give tea and gifts, they will see the 'horrors'. That will demoralise the nation!!
But if the chap was dead, who would care?
As far as auto fire, 3 round, the US army does not bother of replenishment. They have air to create the environment for resupply. India does not have that capability. We have to conserve ammunition, especially in the mountains! Hence, we are the ‘Ek Goli, Ek Dushman’ chaps!
Now, why should the INSAS not be good for COIN?
That is the most simplistic explanation that could be given!