I printed this off for "AR clamp on FIXED STOCK w/Recoil Pad" https://www.thingiverse.com/thing:2214811

Customized version of http://www.thingiverse.com/thing:45117

Created with Customizer! http://www.thingiverse.com/apps/customizer/run?thing_id=45117

Using the following options:

Number_of_Rosettes = 5
Knob_Type = 3
Rosette_Radius = 5
Knob_Thickness = 15
Knob_Diameter = 25
Thread_Size = 5
Knob_Fill = 1
Wall_Thickness = 3
Chamfer_Size = 1
Rosette_Offset = 1