To make a ring laser beam, you need the following entities:
1 env_beam
- Flags to set: ring. (doh)
2 func_trains
- Texture: {blue
- Render mode: solid.
- FX amount 255.
- ORIGIN brush attached!
- Flags to set: Not solid.
Name one func_train "start" and the other one "end" (no quotes).
In the env_beam properties, enter the name "start" in the start entity line, and the name "end" in the end entity line. Set color, beam witdh, stuff like that.
Place both func_train some units away from eachother, try 64. More further space between the func_train means a bigger ring.
Lucky fella's, i recently made a small test map to test die ring effect. And it looks cool. Check out my example map, which is a little bit mroe advanced, because this ring is also moving.
Check it out:
http://members.lycos.nl/michielb55/MuzzleFlash/env_beam_ring.zip(Safe target as)