I have never used that method, so i cannot speak from experience, but I would think that if you work hard to get low rounout on the round as many people do, you would then be undoing that work by moving the metal around when you "crush" the case. your miliage may vary, so try it and find out. Let us know what you find.
Bullets have well documented performance specifications.
Min Velocity info is available, and describes the performance floor of the bullet... DON'T allow yourself to reference F.P.E. as an accurate descriptor of killing power.. You are smarter than a copy editor, and you understand that you can determine maximum (reliable) effective range by comparing your drop chart to published bullet data....... And, dog-on-it, people like you!