Yesterday I played a game and used my Thunderfire cannon (TFC). Once again it was amazingly good. Here was the set-up. A new guy only had 800 points of Imperial Guard and wanted to play. I made a vanilla marine list of 1200 points to team up against 2000 points of Deathwing Terminators. Part of the DW player's problem was his short range, nothing over 24". We set up first and I had my TFC on a far edge with no cover but good lines of sight. Terrain was moderate with 2 ruins, about 5 small hills and 4 craters, evenly distributed. (The DW player set up that table and a few others before the game night started.)

He used DW assault rules. In turn 1 he had nothing on the table so we just moved around a bit. Turn 2 he came in and I fired the Str 6 Ap5 round at his units. I got 3 direct hits and 1 scatter, achieving 15 hits. I killed 4 terminators with the TFC.

Turn 3 I got 15 hits and killed 2 terminators with the TFC (nice saves!)

Turn 4 I got 16 hits and killed 3 terminators with the TFC.

Turn 5 & 6 he was out of LOS of the TFC.

Turn 7 I had bad scatters. He only had 2 models left on the table. I got 4 hits, no kills.

This was my 5th game with the TFC. So far it has never been destroyed, but in one game (my most challenging) the tech-marine was killed in turn 5 after the TFC killed about 13 scouts and the tech-marine killed an ironclad dreadnought by shooting it in the rear armor with the plasma pistol causing the dread to blow up.