First the pics:
Then the boring bits:
Originally I was gonna slap those turrets on Leman Russ hulls, since I found the A.T.A.C. APC (which I use as Chimeras) too light for such use. Then I put together the first turret and just put it on there, and was really surprised on how it looked like.
The turret is an Old Crow one with BitsBox.eu Flak Cannons and GW Exterminator barrels. I liked the beefier look of the barrels.
Also, now I have 2 spare Leman Russ hulls, so... Win-win? I'm thinking a Demolisher and a Hellhound (inspired by this