The best case? This little monster:
With conic warheads due to reduced re-entry speeds (to retain higher terminal speed than tri-conic warheads and be more compact for the arrangement.
The 1800kg number sounds reasonable, if not more, it would make 3 x 600 kg warheads (bus not counted). The R-27 basis is strong enough for such a performance at 2000km range. Due to the increased length, the range performance is certainly above the 2400km (650kg warhead) of the R-27. If we assume 3000km with a 650kg warhead, it is possible that the payload is 1800kg @ 2000km.
From the looks it is that of the typical submunition warhead of Ghadr and Qiam. In worst case it is just a submunitions warhead, which would make it very destructive but an area attack weapon (very good too).
If they have mastered a bus stage (and the separating of the whole conic warhead indicates it), it could position the 3 unguided warheads on an accurate course to achieve something in range of 200m CEP if spin stabilized. A bus would also be ideal to place credible penetration aids into the trajectory.
I have always been a friend of liquid fuel missiles for conventional use. They can easily have a lifetime of 100 years if overhauled a little. Solids need a complete propellant replacement after 15-20 years at best 30.
So your weapon system investment becomes on the one side a very long term one and the high throw-weight gives you three missiles for one, making conventional usage sufficiently efficient (higher accuracy guidance costs pays off etc.). Delivering a payload to up to 2000km will remain a very basic, needed and important capability for the foreseeable future and beyond.
So I like the large diameter and short length of the Khorramshahr. I like the high throw-weight but short "designed" range for which structural changes are necessary. I also support the liquid nature of it due to cost-effectiveness as pointed out. I like that this system proves in a elegant way, that Iran has a reach beyond the self set 2000km, without going beyond 2000km.
Lets see if its a brute force unguided submunition system or a Bus'ed MIRV (and yes I think 3, 600kg full-conic warheads would fit there).
