gun barrel hole topology

Simon_____

hello all, so i've not really done much gun modelling, i just started a piece and i have come to an area of question 
as my image shows i want to have these indents along the barrel, however im not sure if there is enough polys for the round sections? will a normal map make these really smooth or is it best to increase the poly count, and if i need to increase the poly count what is the best way to do that on a rounded barrel? 

Millenia

I would model it flat, then Turbosmooth -> Bend -> Vertex Weld, no pinching at all. Best way to build anything that's going to be a regular cylinder like this.

By doing the turbosmooth before the bend you've got a ton of geo for a nice smooth result.