What is the best solution for this UV problem? I am following tutorial for an AKM and I am having trouble straightening these faces. The reason I am asking this is because the modeling and UV parts are done in 3DS MAX and I use Blender. So far, I have been able to follow along but this part is giving me some trouble. I want to straighten them because I want the texture to follow the shape of the magazine but I don't know how to do that. 

I am still learning how to use TexTools and UV Squares and the Rectify option does not work, as you can see in the first image.

What is the best solution for this problem? Thank you!
My proposed solution:


Map the item as it is. The UV-map is bent.
In the UV-editor, manually straighten the outer edges. Using SX0 or SY0 for instance.
Select the outer edges and pin them. Toggle pinning with P.
Go back to the 3D editor and do the UV-mapping again.


The pinned vertices should stay as they were and the inside should be remapped to follow.



When you pin a vertex in the UV-editor, it is marked with a red border.