There is PBR low-poly gameready model of hand flamethrower. The design of the model is made in the style of science fiction. You can use this in shooters or other similar projects.
You can purchase a bundle including this and other Sci-Fi assets at a discount:
https://www.unrealengine.com/marketplace/en-US/product/2fe17f98024e4800bec6eb08d53d4407
Artstation: https://www.artstation.com/artwork/xJaL9O
Animation preview: https://youtu.be/keCpctxHjos