Headstamp Bunters-How are they made?


#1

As I look at headstamps, there are clearly a lot of ways to produce headstamp bunters. A friend with many years in the business described two methods

HOB Master:

  1. The characters were cut into a steel alloy ‘Hob’ using a very small diameter end mill
  2. The Hob was hardened by heat treatment
  3. The Hob was impressed into a soft (annealed) steel bunter
  4. The bunter was then hardened by heat treatment and subsequently used to impress headstamps onto softer shellcases
    Headstamps using a HOB master may show milling marks at the bottom of the characters

EDM (Electronic Discharge Machining-I think):

  1. Headstamp milled directly into a copper electrode
  2. The electrode was used in an EDM process to directly

#2

Lew, There wasa nice article in issue 453 which will help though it won’t give you all the answers.
Chris P.


#3

Chris, Thanks for the reference to the excellent article. You have also demonstrated that my few remaining gray cells are only capable of retaining information for something under the two years since IAA Journal 453 was published!!!

George Koller did a much better job of describing the Hob and EDM processes than I did. He also touched on the process of directly stamping on the headstamp which appears to be what the Canyon Cartridge Company did. The bunter is used to form the head of the cartridge, but sometimes it appears that cartridges are made and the headstamp is added later by using a seperate stanp die or in some cases having the headstamp actually machined into the case head (either mechanically or with a laser.

Does anyone know of other processes???


#4

Some of the headstamps on early rounds from around the turn of the last century look like the bunter could have been cut by an engraver with a hammer ans small chisel. This is especially true for countries whos industrial facilities were likely primitive. Is this the case that they were hand engraved by a craftsman using a hammer and chisel?


#5

Lew,
Undoubtedly the work was carried out by Hob-bits!