collapse collapse

* Links

* Forum Menu

* User Info

 
 
Welcome, Guest. Please login or register.

* Who's Online

* Board Stats

  • stats Total Members: 2411
  • stats Total Posts: 87587
  • stats Total Topics: 14991
  • stats Total Categories: 5
  • stats Total Boards: 63
  • stats Most Online: 721

* Search



Author Topic: Chamber Mark Research Question  (Read 26958 times)

0 Members and 1 Guest are viewing this topic.

KClarke

  • Guest
Chamber Mark Research Question
« on: June 27, 2005, 11:56:27 AM »
Hello all,
          A recent case in the lab has brought up the question of Chamber Marks alone as proof of "fired in" status of a shell casing, as opposed to just "chambered and extracted in" status.

          We've discussed the possibility of doing a study to see if we can conclusively determine "fired in" status based solely on chamber marks.  I would like to ask if anyone here has seen or heard of such a study being done, or published before?  If so, could you please direct me to it?  I'd like to try and collect as much information that's been done about chamber marks as I can before we get too far ahead of ourselves.

          Thanks in advance for any help you can give,

Ken

Offline Bob Shem

  • Global Moderator
  • *****
  • Posts: 3327
  • Gender: Male
Chamber Mark Research Question
« Reply #1 on: June 27, 2005, 01:22:34 PM »
Here's an article that may be of some assistance.
Robert J. Shem, 4900 Buckingham Way., Anchorage, AK  99503, ph 907 952-2254, bobshem@alaskan.com

Offline Scott Doyle

  • AFTE Member
  • ***
  • Posts: 1929
  • Gender: Male
    • An Introduction to Forensic Firearms Identification
Chamber Mark Research Question
« Reply #2 on: June 27, 2005, 04:51:26 PM »
As a new graduate of the "Criteria for Identification Workshop", those great looking "fireformed" marks look a lot like sub-class characteristics.

 :D

Offline Scott Doyle

  • AFTE Member
  • ***
  • Posts: 1929
  • Gender: Male
    • An Introduction to Forensic Firearms Identification
Chamber Mark Research Question
« Reply #3 on: June 27, 2005, 04:57:20 PM »
Sorry, didn't mean to get the topic off track.  Just ignor that prior post   :)

Offline Bob Shem

  • Global Moderator
  • *****
  • Posts: 3327
  • Gender: Male
Chamber Mark Research Question
« Reply #4 on: June 27, 2005, 06:43:43 PM »
Scott, it may be too late for "de-programming" to be effective with you. :roll:
Robert J. Shem, 4900 Buckingham Way., Anchorage, AK  99503, ph 907 952-2254, bobshem@alaskan.com

Offline Laura Fleming

  • Training Seminar Steering Committee
  • *
  • Posts: 478
  • Gender: Female
Chamber Mark Research Question
« Reply #5 on: July 08, 2005, 07:52:44 AM »
A few years ago Caryn Tucker from the Illinois State Police-Chicago Lab did some research for her Masters on consecutively made chambers from Hi-Point. I don't believe her study was ever published. I did take the blind test she put together using the consecutively made chambers....and successfully completed it. I am not certain if she has expanded her study or not. You may want to call her to discuss your topic-312-433-8000.

Offline Caryn Tucker

  • AFTE Member
  • ***
  • Posts: 4
Chamber Mark Research Question
« Reply #6 on: July 12, 2005, 04:55:48 PM »
I am currently working on a research project regarding chamber identification.  I am working with ten consecutively manufactured chambers from Hi-Point and Ruger, and am trying to obtain chambers from Keltec also.  I began this study as part of my research for my thesis, and am now expanding this.  I have not published this work yet.  You can call me to discuss, 312 433-8000x2226

Offline Tsuneo Uchiyama

  • AFTE Member
  • ***
  • Posts: 9
  • Gender: Male
Chamber Mark Case Report from Japan
« Reply #7 on: December 06, 2005, 04:53:01 AM »
Marking originated from errosion of barrel or chamber is unique in nature, and it is possible to identify using these markings. However reproducibility of such marking is usually not so high than Bob's 22 rimfire case example.

Here are comparison photos on the mouth of  two cartridge cases of Tokarev.
Tokarev cartridge uses Berdan primer and is non-relodable. I encountered such deep chamber mark for the first time after examining more than 1,900 Tokarev test fired cartridges.

I do not think such deep chamber mark impressed only by chambering and extracting procedure.
The markings are from open case, and I have not confired that.
Tsuneo Uchiyama
AFTE Member

Offline Robert Warburton

  • AFTE Member
  • ***
  • Posts: 56
  • Gender: Male
Re: Chamber Mark Research Question
« Reply #8 on: December 07, 2005, 09:53:57 AM »
Thanks to Bob for attaching his article on the rimfire cartridge cases and chamber marks.

From experience as a gunsmith and firearms examiner I have found that the greatest area for chamber marking on rimfire cartridges and particularly fired cartridge cases is where the firing pin aligns with the chamber mouth. When rimfire firearms are 'dry fired' their firing pin nose can impact with the barrel's chamber mouth causing indentation and burring damage. Some firearms experience repeated 'dry firing' and display considerable damage in this region which is transposed onto the fire form cartridge case.
Bob Warburton
FACTS
Forensic Analysis, Consultancy & Training Services

 

Countdown Clock

* Recent Posts

* Headstamp Guide

SimplePortal 2.3.5 © 2008-2012, SimplePortal