The story is excellent, and no-one argued that that it couldn't be fixed.

That wasn't the point.

Yet you still haven't made your point. I usually like reading your posts, Tenebrae, but now you're being deliberately obtuse.

Welcome to Warhammer 40k. Even without talking about RPG game mechanics, it is silly and physics need not apply. That is all.

Anyway, I always assumed that promethium was fairly common (scarce availability, so like hunting rifles), and tended to be composed of whatever was common enough on the planet of origin. I figured thats why all flamer weapons have pilot lights when the purified Promethium fuels used by the Imperial Guard supposedly ignite on contact with oxygen (and are also self oxidizing so they can burn in space and underwater... wut).

You're right I was thinking of nephium or whatever the **** is, promethium isn't that rare although I imagine it's a restricted substance on most Imperial planets not that it would matter to an RT.

I dunno about it's destuctive capability though because it seems to me that unless you misted it or somehow else got a really good fuel air mixture I don't think it'd be a great explosive. In a liquid or gel form you'd maybe get one good fireball and then just everything nearby being on fire a whole lot. If it leveled a building it would be because it burned it down.

That's kind of the point of this thread though, it DOES make a crappy explosive, hence the change in damage and blast size. Most of the damage is likely gonna come from the fire rather than the explosion.

Except when it's been atomized and ignited, then it can make a big ass explosion. Hence all the talk about thermobaric weaponry.

Bear in mind that those five kilos would each be blast 4, and deal 1d10 damage. 5d10 blast 20 is more catastrophic by far.

Edit: although, having seen Tenebrae's explanation, I could make a case for

Damage= ((mass in kilos)^1/2)d10

Blast ((mass in kilos)^1/3)

But that's slightly more complicated.

^ this guy did not read the rest of the thread.

Per my suggestion of scaling based on the cube root of mass, 36 kilos of promethium would deal 3d10 damage blast 13- I'd say that's fair for an incendiary satchel charge. A clever Tech-use/Demolitions check might let you convert it to a thermobaric charge, in which case I'd allow the scale to go to square root, for 6d10 blast 24, at which point we are now competing with a lascannon for damage, no?

actually based on your equations then the blast would be 3.301 or likely rounded up to four not 13 and with 6d10 damage still usefull though