Changing section shape of framing elements

[greg23.se]

Hi! Sorry, I'm new to Revit and wasn't able to find an answer to this question. When I open up C-Shapes from C:\ProgramData\Autodesk\RVT 2021\Libraries\English-Imperial\Structural Framing\Steel\AISC 14.1 it is automatically set to a C-channel sloped flange. When I go to Family Category and Parameters and change the section shape to a C Profile, the properties box recognizes this change but the model stays the same. Am I trying to do this the wrong way or is there something more I need to do? Thanks!

[greg23.se]

I'm also trying to change the size of the C-Shape using presets in the AISC database (ie. Switching from C12X30 to C6X8.2). However, there are only two of these available to me, those being C12X30 and C15X33.9. When I go into the notepad document right under the C-Shapes file I can see a full list of the AISC database, but when I load any of these they don't show up.

[Anonymous]

I am not sure that I quite understand 100% your issue. Have a look if my answer is aligned to your question.
Changing your profile from one to another will not change the model itself (it only changes the properties of the section profiles), you must change the profile family yourself (you can use the exist C-shape profile and Save As a new family). You can find the current C-shape profile in the Project Browser -> Family -> Profile.

Look at the photos below: