Well directed kinetic energy can be devastating and has been used for such effect since ages, for example the old canons with passive cannon balls. Rail guns are their new sought after variants.
The famous bunker-busting smart-bombs circa first gulf-war were fin stabilized old tank barrels packed with explosives. It is their weight, owing to the high density metals used in the barrels and their small cross section (and hence extremely high terminal velocity) that gave them their extreme penetrative punch. Enough to pierce through tens of layers of strengthened concrete, each several feet thick and explode with devastating effects underneath. It was very important that they did not topple in flight though. So stabilization was critical.
Even the modern anti-tank weapons are essentially glorified darts, but much, much heavier. They kill tanks by sheer kinetic energy alone. They have been found to be harder to defend against, compared to other variants like HEAT that penetrate tank armor by the use of a high speed, dense jet of liquid metal, or HESH which are sort of like cow-pies made of high explosives that set off spalling bending moments inside the tank 'hull'.
the main benefit of the small cross section is not increased terminal velocity through the air but rather to maintain velocity through the bunker (or armor in the case of the "sabot" or APFSDS anti-tank round you mention)
To generate the force of a 1 ton TNT explosion, a shell shaped bomb moving at 800 ft per second will need to weigh 311,000 pounds. [K.E.=1/2 x m x v x v]
It takes a fraction of this to dent a tank out of commission, provided you're accurate. The overpressure wave bouncing around inside the tank cabin created by a direct hit probably has stunning effects on the crew and may not kill them if the cabin isn't crushed - although it could do terrible damage to the ears, lungs and stomach.
For another comparison, modern KE sabot anti-tank rounds (what tanks shoot at other tanks) use penetrators weighing from 4 to 8kg, with a muzzle velocity of around 1500m/s, giving a low of end of ~9MJ. Granted, this is ignoring air friction, and must punch through the front armor (much much thicker) than the top armor that bombs go through.
Also... as a cost comparison, JDAM (the US GPS guidance) kits cost 20-30k per kit (you strap them onto 'dumb' bombs). For the actual bomb itself, you're talking on the range of a buck or two per pound... the inert training versions are much cheaper than that. Explosives are cheeapp. Silicon is pricey.
See link below for pricing information! (The Mk-84 is the 2000lb 'dumb' bomb, it's listed along with its training/concrete version).
Just a thought, but if the silicon is expensive, could you potentially engineer the majority of the computerized parts into a UAV that could detach at the last moment and fly back?
I wonder what they're using for guidance. GPS and inertial guidance aren't accurate enough and anyway aren't useful against moving targets.
That leaves laser guidance kits, which tend to be pretty expensive. Probably takes more than one attempt on average, too.
On the other hand, you probably don't need to worry much about temperature and humidity when you store concrete munitions. Or maybe they mix up a batch of bombs before the sortie - "You can't launch yet. The concrete isn't dry."
They had 'smart' versions of bombs and missiles back in 91. They just didn't have GPS guided ones/cheap guided munitions. They have both now (with cheap in a relative term).
To be specific, the relatively cheap GPS-guided bombs that became available after the 1991 Gulf War consisted of new electronics and new tail sections bolted onto ordinary "iron" bombs manufactured many years earlier.
I think you have to be very accurate with almost any kind of bomb. The soviets made 10+ megaton h bombs partly because they didn't have accurate delivery systems.
The famous bunker-busting smart-bombs circa first gulf-war were fin stabilized old tank barrels packed with explosives. It is their weight, owing to the high density metals used in the barrels and their small cross section (and hence extremely high terminal velocity) that gave them their extreme penetrative punch. Enough to pierce through tens of layers of strengthened concrete, each several feet thick and explode with devastating effects underneath. It was very important that they did not topple in flight though. So stabilization was critical.
Even the modern anti-tank weapons are essentially glorified darts, but much, much heavier. They kill tanks by sheer kinetic energy alone. They have been found to be harder to defend against, compared to other variants like HEAT that penetrate tank armor by the use of a high speed, dense jet of liquid metal, or HESH which are sort of like cow-pies made of high explosives that set off spalling bending moments inside the tank 'hull'.