This part required an external radius to match the pieces I had already made and there certainly is not a great deal of elevation for the guns. I could imagine if the tank went down a ditch or a smallish hill you would not be able to get the guns low or high enough to do any shooting. Perhaps they just stopped every time they wanted to empty their rounds at some thing. Anyway they are starting to look like Vickers turrets now but they will look better when I complete the gun ports.