We look at a design for drop away rail buttons to reduce drag on a rocket. The design also supports a wide variety of launch rail profiles.
Button Drag Characteristics: https://www.apogeerockets.com/downloa...

Fly away guide video:    • Test flight with 75mm flyaway rail gu...  
by Chuck H

STL files for the rail buttons shown in this video can be downloaded from here:
http://www.aircommandrockets.com/day2...
Extra information is included on the bracket.