I don’t know how you got the value of 271kg of fuel usage per hour. That is very low. If true that is great. Because according to Kale’s own site this engine uses 1.18 kg of fuel per decaNewton thrust. As it has 320 deca newton of total thrust it should use 377kg of fuel per hour. That includes the fuel used in lubricating the engine during operation.
All values open to public regarding SOM are very vague. Even the length of the missile is not exact. (~4m) . The heaviest version of SOM is 660kg. Standard SOM is ~600kg. Take away the engine (50kg) and explosives (230kg), you end up with 320kg (or 380kg for the heavier version). The empty lighter missile and fuel has to be 320kg. So it doesn’t leave much room for fuel. Your 100-120kg of fuel weight however seems realistic in view of the weights that we know. But if 1.18kg/hr/decaNewton value is correct, then ~ 330km range is more plausible.
Just to add, I remember being discussed at “Key-Aero” about the empty weights of a1000+kg JASSM and a 1400kg Taurus missiles being around 500kg and 800kg respectively. SOM is much smaller. But still, the 320kg doesn’t leave much room for fuel and a body; even if it is mainly composites.
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