Page 1 of 2 12 LastLast
Results 1 to 10 of 11

Thread: Interesting findings from my dissertation.

  1. #1

    Interesting findings from my dissertation.

    Hi Chaps, I've just finished my dissertation "A ballistic investigation into UK air gun crime and law" for my forensics degree though most of it was just stating what most shooters know proving it, and putting it into scientific words i did find some oddities that might be of interest to some people.


    • A 10ftlb RWS superdome will travel 147mm (5-6inches) into a block of ballistics gel the same density as human abdomen. which would be straight through a man with a 34inch waist approximately)
    • the same pellet will create a non-permanent channel of up to 25mm transmitting shockwaves through the medium over 10 inches from entry site (possibly further that's how big the gel was)
    • Light source has a noticeable effect on chrony results; a change from an led light to a fluorescent bulb changed the mean by 20fps or o.2ftlb.
    • It's pretty simple to match a pellet to an unknown using a comparison microscope.
    • You could rule out pellets from being a match using analytical chemistry


    Click image for larger version. 

Name:	3.PNG 
Views:	46 
Size:	96.1 KB 
ID:	69908


    Scooby

  2. #2
    Sounds like fun!

    Point one illustrates the limitations of ballistic gel as a tissue analogue; try a pig abdomen (guts in) and see if you get 6 inch penetration! (Dave Cameron is a world authority on pig penetration, BTW.)

    For my A-level physics project, many years ago, I built a rig to measure pre- and post-target pellet velocities. This, could then be used to calculate the energy imparted to the target. A still camera photographed the passage of the bullet through the target to capture the temporary wound channel. Tested lots of different pellet designs.

    All this his had to be done in a pitch-black classroom! School risk-assessments were probably different in those days!

  3. #3
    Tried a battery powered halogen bulb for the crony? nice clean light...
    I remember measuring revs optically, was a disaster with AC lights no prob with a torch.
    edi

  4. #4
    We use an infra red lighting system on the current club chronograph. With the previous chronograph we built a light box that used filament lamps. All attempts to use that chronograph under the fluorescent lighting was a waste of time due to inaccuracies caused by the tube flicker.

    I've also experienced errors when shooting outdoors when we set up under a tree and the one screen was in shadow and the other wasn't. Once again a chronograph light box would have been the answer or else one of those magnetic field chronographs.
    It's the calibre of the shooter that counts not the calibre of the rifle.

  5. #5
    Problems with a pigs abdomen is its expensive heavy and a biohazard which doesn't bode well for research. and its a lot of cleaning plus there isn't a maintained blood pressure or smooth muscle contraction either it just a non-homogenous non-repeatable mess. There are documented cases of this level of penetration

    For the chrony i overall conclusion was chronies suck scientifically.Radar-based systems are the standard for larger munitions but may be too expensive forensically. A possibility that was though of was a power transfer system. e.g. compress the spring or swing the pendulum as work done is directly proportional to the energy required.

    Battery powered items will have a decrease in output as the power source drains making them too inconsistent for forensic applications.

    Scooby

  6. #6
    Scooby have you read about the Strasbourg tests?
    If not i think you will find them very interesting.

    Ian.

  7. #7
    Quote Originally Posted by whatwouldscoobydoo View Post
    Problems with a pigs abdomen is its expensive heavy and a biohazard which doesn't bode well for research. and its a lot of cleaning plus there isn't a maintained blood pressure or smooth muscle contraction either it just a non-homogenous non-repeatable mess. There are documented cases of this level of penetration
    I'm not suggesting that you substitute ballistics gel with a pig abdomen for your research; biological materials are always a nightmare for consistency (ask me how I know!) However, I think shooting a 10ftlb RWS pellet at a pig abdomen would cast serious doubt over your suggestion that it could penetrate through a 34" waist man.

    Having had hands-on (and "in") experience of gunshot trauma in humans (not to mention deer, rabbits etc.) I think your inference is wrong.

    That said, good luck with the dissertation- I, for one, would be interested in seeing more of it! I always found Forensic Pathology lectures fascinating; they were always well-attended, particularly those of Prof Sir Bernard Knight and Stephen Leadbeatter.
    Last edited by xavierdoc; 09-05-2016 at 21:32.

  8. #8
    Quote Originally Posted by Whitebeard View Post
    Scooby have you read about the Strasbourg tests?
    If not i think you will find them very interesting.

    Ian.

    4 years ago I visited an excellent facility in Strasbourg: it had a giant operating theatre which could accommodate around ten anaesthetised pigs at once. We practiced all manner of emergency surgery but no opportunity to research terminal ballistics! Didn't get to eat the pigs after, either.

  9. #9
    The Strasbourg Tests were carried out in 1991 over a period of 18 months, somewhere around the eastern seaboard of the USA, French Alpine Goats were the test subjects and a total of 611 were shot to test the terminal ballistics of various handgun calibres.
    It was extremely controversial having alleged to be primarily funded by the US military the first details leaked to the public around 1995.

    Ian.

  10. #10
    Quote Originally Posted by xavierdoc View Post
    I'm not suggesting that you substitute ballistics gel with a pig abdomen for your research; biological materials are always a nightmare for consistency (ask me how I know!) However, I think shooting a 10ftlb RWS pellet at a pig abdomen would cast serious doubt over your suggestion that it could penetrate through a 34" waist man.

    Having had hands-on (and "in") experience of gunshot trauma in humans (not to mention deer, rabbits etc.) I think your inference is wrong.

    That said, good luck with the dissertation- I, for one, would be interested in seeing more of it! I always found Forensic Pathology lectures fascinating; they were always well-attended, particularly those of Prof Sir Bernard Knight and Stephen Leadbeatter.
    Cardiff grad?

Similar Threads

  1. Interesting
    By SimpleSimon in forum Off Topic
    Replies: 5
    Last Post: 01-08-2015, 20:42
  2. Help with dissertation data collection
    By eric parker in forum Deer Stalking General
    Replies: 6
    Last Post: 30-06-2013, 17:04
  3. Might be interesting
    By Fabnosh in forum Deer Stalking General
    Replies: 0
    Last Post: 25-03-2013, 13:14
  4. Stalking Questions: Dissertation Research Project
    By nielaj in forum Deer Stalking General
    Replies: 14
    Last Post: 25-02-2010, 10:03
  5. dissertation?
    By toby in forum Deer Stalking General
    Replies: 7
    Last Post: 10-01-2008, 16:59

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •