Go Back   British Ordnance Collectors Network - Inert Ordnance from WW1, WW2 and more > ORDNANCE > Projectiles

Notices

Simple Question 20mm Becker

Hey there!

It looks like you're enjoying but haven't created an account yet. Why not take a minute to register for your own free account now? As a member you get free access to all of our forums and posts plus the ability to post your own messages, communicate directly with other members and much more. Register now!

Already a member? Login at the top of this page to stop seeing this message.

Reply
 
Thread Tools Display Modes
  #1  
Old 31st January 2010, 07:18 PM
Lou's Avatar
Lou Lou is offline
Premium Member
 
Join Date: Dec 2007
Location: Wisconsin U.S.The land of great cheese
Posts: 328
Simple Question 20mm Becker

Could someone please tell me what direction the tracer element threads in a 20mm Becker projectile are??
Ok,are the threads in the bottom of this projectile righty tighty,or lefty tighty?
Attached Images
File Type: jpg Unknown 002.jpg (97.9 KB, 62 views)

Last edited by Lou; 1st February 2010 at 07:02 PM.
Reply With Quote
  #2  
Old 6th February 2010, 09:45 PM
a1brassansteel a1brassansteel is offline
Junior Member
 
Join Date: Apr 2009
Location: Verwood
Posts: 3
Smile 20mm becker

Hi my projectile has no base,there is no threads inside so it may be that they were pressed in,hope this helps.
Reply With Quote
  #3  
Old 6th February 2010, 11:19 PM
kahu1 kahu1 is online now
Senior Member
 
Join Date: Jan 2009
Location: New zealand
Posts: 154
Images: 26
Hi Lou,
I've got a coUple of these.
they are just a press fit,i had to soak in oil for a few days to ease them out,then carefully scratched away at the primer comp,needs soaking too!.
cheers Bob
Reply With Quote
  #4  
Old 8th February 2010, 04:28 PM
Lou's Avatar
Lou Lou is offline
Premium Member
 
Join Date: Dec 2007
Location: Wisconsin U.S.The land of great cheese
Posts: 328
Thanks guys,
Yes,it turned out it was a press fit plug. I wonder if design lasted long? One would think that at firing the plug and the shells contents would be left behind?
Reply With Quote
  #5  
Old 8th February 2010, 05:10 PM
glevum's Avatar
glevum glevum is offline
Premium Member
 
Join Date: Jan 2009
Location: UK
Posts: 202
The pressure generated during firing is the same over the whole base of a shell when fired. So the tracer would see the same pressure as the rest of the shell, hence they would not tend to separate.
Reply With Quote
  #6  
Old 8th February 2010, 05:29 PM
Lou's Avatar
Lou Lou is offline
Premium Member
 
Join Date: Dec 2007
Location: Wisconsin U.S.The land of great cheese
Posts: 328
I agree with that,but "when lit" wouldnt the increased internal pressure push that plug out?
Reply With Quote
  #7  
Old 8th February 2010, 10:50 PM
Chris 42 RQ's Avatar
Chris 42 RQ Chris 42 RQ is offline
Premium Member
 
Join Date: Dec 2007
Location: Berkshire.
Posts: 1,931
Images: 100
Thumbs up Load over area!

Go back to basic engineering and the equation of "Load over area" and you will see that the pressure over the tracer element will actually tend to seat it harder into the shell body.
__________________
CHRIS
Reply With Quote
  #8  
Old 9th February 2010, 04:59 PM
nitrocellulose nitrocellulose is offline
Member
 
Join Date: Feb 2010
Location: Central Ontario Canada
Posts: 31
Images: 3
Think of Newton's Third Law as well, "For every action, there's an equal and opposite reaction."

The heated gases generated by the buring tracer should act in a similar manner as a rocket motor. Obviously there is no where near enough force to aid in propulsion but the idea meets the requirements in Newton's Law.

This means that the tracer would seat itself further into the tracer cavity once ignited. The pressure is being exterted throughout the face of the tracer element.
Reply With Quote
  #9  
Old 15th March 2010, 08:10 AM
kahu1 kahu1 is online now
Senior Member
 
Join Date: Jan 2009
Location: New zealand
Posts: 154
Images: 26
Found this in a General staff artillery guide ,march 1918.
Doesn't show the base plug but maybe they didn't all have it ?
I like the "tracer emits a trail of sparks"!

cheers Bob.
Attached Images
File Type: jpg 002.jpg (94.7 KB, 17 views)
File Type: jpg 003.jpg (91.1 KB, 9 views)
Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT +1. The time now is 10:52 AM.

Template Selector:

Powered by vBulletin® Version 3.8.6
Copyright ©2000 - 2010, Jelsoft Enterprises Ltd.

Site Designed and Maintained by David Brown Software And Website Design

Powered by vBulletin® Version 3.8.6
Copyright ©2000 - 2010, Jelsoft Enterprises Ltd.
Forum SEO by Zoints
Page generated in 0.10783 seconds with 13 queries