coil spring not flat

Hello!

I found one of my coil spring sides is not a flat cut. its a bit angled. If I measure the spring in one point off the circunference ir reads 139.3 mm and if I do the same on another point It reads 138.00 mm. 

The thing is that I makes difficult setting preload as When It starts touching the spring there is a lot of the spring still not touching. I Have to give almost 2 mm off preload to makes It flush  and to take out any play on the circlip and retaining colar. And that kills a alot my sensitivity. 

Is this normal? I wont mention the brand but its a very expensive spring, that I bought new a year ago and starting using It this month.