I'm hoping I can get some information re lapping small diameter holes. I would like to try making a few dies to re-size cast lead bullets (approximately .002"-.003" smaller than their as cast size). The bullets are sized by pushing them through a die, approximately 1.5" in length, with an appropriately sized hole. The die I would like to make first will need a hole .270" in diameter. I will be using a small lathe to make the die, using mild steel.
I've made a few dies before, drilling the hole with the closest sized drill, then smoothing/enlarging the hole with abrasive cloth. I have not had much luck getting the right size hole with this method. I've discovered “barrel laps” on the internet and it seems to me like this might be the right tool for a job like this. I would really appreciate any information on how to use barrel laps, what grade of abrasive, etc. I would welcome any other tips for making a part like this.
I've made a few dies before, drilling the hole with the closest sized drill, then smoothing/enlarging the hole with abrasive cloth. I have not had much luck getting the right size hole with this method. I've discovered “barrel laps” on the internet and it seems to me like this might be the right tool for a job like this. I would really appreciate any information on how to use barrel laps, what grade of abrasive, etc. I would welcome any other tips for making a part like this.
