I've tried all of those and then some (e.g. "ATGM"), plus various specific names (like "FGM-148 Javelin", "M1 Bazooka", or "RPG-7", which are all quite iconic and well-recognized so I thought some of those may appear in training data) - all no bueno. Models are simply unaware about such devices, best of their "guesses" is that it's a weapon, so they draw something rifle- or pistol-shaped.

And, sure, that's what LoRAs are for. If I can figure out how to train one for FLUX, in a way that would actually produce something meaningful (my pitiful attempts at SDXL LoRA training were... less that stellar, and FLUX is quite different from everything). Although that's probably not worth it for making a meme picture...