This isnt a very public related thread as im not wanting replys from "un-experienced" with source.
The thing is, I got an idea how we should make the 'flame'' of the flamethrower and I must write it all down so that others will understand its beauty. And so we can discuss it properly.
Source works that way that if an animation that leads to another and dont stop on the same place(location) as the first it will do a little auto-animation so it dont just pops there as in other old games, it smoothly moves to the next animation.
As my picture shows, from the end of the "attack1" animation to the beginning of the "idle01" animation:

By making a 3d cylinder,
shaping it as a flame and colouring it yellow we will have our flame:

Just that its not going to be animated, and theres the tricky part...
This grey lines represent the bones which the flame-model will have:

By making a small animation on 8 frames where each fram will represent one direction,
fram1: up left,
frame2: up middle,
frame3: up right,
frame4: middle left,
(This one, which would be the fifth: the player aint moving his sight, meaning he's not looking around so the middle-middle animation will have an own idle animation that makes it look like a burning flame)
frame5: middle right,
frame6: down left,
frame7:down middle,
frame8: down right.

As the player is moving his aim in a sertain direction the 'code' will play a sertain frame of the flame-animation.
For example: if the player would move his aim to the top right the animation thats played would be: "frame6: down left" But only while he is moving. when idling again the idle animation would be looping (if he's holding the trigger in that is).
And for more visual effects there should be smoke in forms of particles that spawns all over the flame and hovers upwards rather violently.
If there is some uncertanty I will try to explan, the risk that i forgot something while writing is quite big :P
ps. the pictures wasnt really something I put any effort in...