I haven't checked the actual specifications for CRAM, but physically it can only be effective for much lesser area and for much less intensity. In real war scenario on would have hundreds of flying rockets and shells at a given moment, and a gun can only aim at one target only. As I said a system similar to Iron dome, where you can target multiple objects simultaneously or something similar to Guided anti artillery projectiles(eg 76mm 50 mm etc), where the anti projectile can correct mid-course direction using radar, that will be an effective solution.. I think that iron dome is quite close to that as initial investment in radar is always useful, even if you are don't have enough anti projectiles, it gives you the warning of incoming threat and also even of you take a hit, you know the enemy location for retaliation fire. It itself gives an advantage. But what will matter most is that the cost for each anti missile or anti projectiles fired for each enemy rockets. If you have a system which is coupled with the Iron doe like radar and a guided 50mm anti artillery shells(where the gun is able to fire at-least one round per second with a kill probability of more then 90%). A single guided anti artillery projectile should not be that costly compared to existing iron dome missiles(@ 40K$). Or better would be to have both the iron dome type missiles and anti artillery system coupled with one radar, where the missiles can form the 15km to 7km of defense area for multiple barrage and anti guided projectile for less then 7km and only for less intensity barrages(considering they would be even cheaper then anti missiles of iron dome). And again I'm suggesting this strategy/system only for offensive forces or the border forces ..Don't couple it with the other defense systems. As deep keys strategic areas will not come under fire of such missiles or artillery systems anyway, they definitely need a system like Aakash bare minimum in case of India. India can afford to take hit near border if enemy decide to use sophisticated arms unlike Israel in real war, hence the purpose is totally different.