The greater the RPM's the tool your using has the better job it will do. Oh and fine toothed also. I have cut tips many time to get faster action and never had a problem. Maybe you should check with Mike at M & D's before the snippage occurs.
Swimmer a.k.a. YO YO MA
Serial Mailbox Killer/Seal Fisherman
It takes a bit more time , but I've had success with a mini-triangular file. It leaves a nice clean cut. I'm sure there are more high tech solutions but this works well.