Modeling Help with Curvature

anotherdoseofcorey

So I've been trying to Model Megatron's canon and can't seem to figure out how to get the curvature at the end of the canon with the little tubes coming out. I'm stumped and could use some insight from other modelers.  

Ghogiel

Maybe start with a plane, find the right amount of segments, cut in the holes/details, then bend it into a cylinder.

something like that but less crap https://www.youtube.com/watch?v=B2D1Ti60B_k

sacboi

A @FrankPolygon solution, I think specifically pertains too your issue:

https://polycount.com/discussion/comment/2735862/#Comment_2735862