Alright, Adams very helpful post has given me the reason to start over with this gun.
This time I thought I should do it right and scaled the drawing according to the plan found on navweaps.com.
See the link below:
Your drawings are also quite nice. I do prefer to have the top part of the gun shield a bit thicker, though.
I believe that you have to add the odd 1 pixel in SB-scale to fully bring out the detail or to replicate the look of a smaller part.
I guess it all comes down to preference on a gun / part this small.