I’m currently doing some studies in pyro on how to do a slo mo muzzle flash. One thing that I am trying to get is a flame with a typical conal-like shape that muzzle flashes take. So far the method I have in trying to get that shape is emitting fuel from a cone-shaped geo before igniting it. The thing that’s in the way of that is the swirling that’s occurring in the sim, which gives it a horizontal, mushroom cloud look. I tweaked the confinement values all over the place with the same results. Is there a parameter or gas node etc. to tweak the swirling flow to get that muzzle-flash-cone shape? Also, another thing I noticed is that even though the fuel source node has a velocity direction set up, when I check in DOPs the fuel itself doesn’t really move.

Try adding custom velocity fields and a collision object that drives the fluid outward. This created a cone like shape for me after explosion. You can also advect fuel a bit.

I'd also try to emit for a shorter amount of time and/or use a particle sim as the source for fuel and velocity.

Cheers