close
Long Range Hunting Online Magazine


Go Back   Long Range Hunting Online Magazine > Magazine Articles > Technical Articles - Discussion

Reply

Pressures, Case Strength and Back Thrust

LinkBack Thread Tools Display Modes
  #1  
Unread 08-22-2010, 02:43 PM
Administrator
 
Join Date: Mar 2008
Posts: 1,118
Pressures, Case Strength and Back Thrust

Quote:
One of the most important developments in firearms history was the brass cartridge case that first came onto the scene just before the Civil War. In 1856 a dentist named Maynard patented a brass cartridge case that would expand when fired and seal the rifle chamber to close off any escape of powder gases. This forced all pressure to push behind the bullet and send it out the barrel with the best velocity. Sealing of the chamber was a major step in the development of breech loading rifles. Prior to that, all breech loaders spit a lot of fire and brimstone out the rear of the action into the shooter's face.... They were not any too popular in those days.... Read More...
This is a thread for discussion of the article, Pressures, Case Strength and Back Thrust, By Bob Jourdan. Here you can ask questions or make comments about the article
__________________
.
What's In Len's Backpack?

See Len's take on his own 51 items.
Reply With Quote
  •   #2  
    Unread 08-22-2010, 05:16 PM
    Platinum Member
     
    Join Date: Nov 2003
    Location: Washington State
    Posts: 2,726
    Re: Pressures, Case Strength and Back Thrust

    Great read on backthrust/chamber friction related to case dimensions and geometry, Len. Thanks. I was thinking about this 2-3 yrs ago and wondered how dry/clean my chamber and cases were. Started swabbing the chamber with acetone as a last rifle cleaning step to completely clean/dry it out before shooting and giving brass walls a quick wipe as well as a last step before storage in the ammo box. The theory was to create more chamber wall friction and less backthrust...who knows.
    __________________
    In the beginning God created the heavens and the earth. Genesis 1:1

    "And can the liberties of a nation be thought secure when we have removed their only firm basis, a conviction in the minds of the people that these liberties are the gift of God?" Thomas Jefferson - Notes on the State of Virginia

    www.wildsidesystems.com - Shelter for Your WildSide - http://www.youtube.com/watch?v=tYwgo...&feature=g-upl
    Reply With Quote

      #3  
    Unread 08-22-2010, 05:30 PM
    Platinum Member
     
    Join Date: Jan 2004
    Location: Blackfoot, Idaho
    Posts: 8,859
    Re: Pressures, Case Strength and Back Thrust

    Good read,

    The image on page two is mislabeled.
    Reply With Quote
      #4  
    Unread 08-24-2010, 05:01 AM
    Silver Member
     
    Join Date: Jul 2009
    Location: Salmon, Idaho
    Posts: 392
    Re: Pressures, Case Strength and Back Thrust

    Good read Bill,
    I was excited when I saw this article and your name along with it. I'm very interested in the 6.5x55 BJAI. How does it compare to say the 6.5-284? Would you consider it to be a worth while modification to a 6.5x55 rifle specifically built on a '98 Mauser action. I'm having a great time with my Swede but case life is lacking and I'm considering recutting the chamber to your Ackleyized cartridge.
    Reply With Quote
      #5  
    Unread 08-24-2010, 05:47 PM
    Silver Member
     
    Join Date: Dec 2009
    Location: Michigan
    Posts: 253
    Re: Pressures, Case Strength and Back Thrust

    Bob,
    Great job on the article! always enjoy your work, I built a B.J.A.I. 6.5x55 some years back on a M96 Swede action and never regreted it. Oh yea I picked up a M96 Swede 22br "tight neck" from Bob White ( Built by "Bob Jourdan" you did a fine job machining that one). RL15 and 50 grn noslers are the one hole recipe there, Thanks again for some great articles.



    Bob
    __________________
    Bob the nailer
    one ragged hole...the quest for accuracy continues.

    NRA Life member
    Varmint Hunter Association member
    American Gunsmith Association
    www.knowyourzero.com
    Reply With Quote
      #6  
    Unread 02-13-2011, 12:12 PM
    Silver Member
     
    Join Date: Jul 2010
    Posts: 420
    Re: Pressures, Case Strength and Back Thrust

    Maybe someone has an answer. one of my wildcats is being confusing. I used a .375 R.UM. for the parent brass and made a cartridge that is similar to the .375 Dakota. Its inspiration was to make a longer version of a W.S.M. with .375 diameter bullets. Very little taper and tight headspacing. My concern is that I (QUESTION?) by design eliminated case stretching as one of the common pressure indicators. I honestly do not know if ease of extraction and fired case measurements will begin to show signs of overpressure before a critical loading is reached. -- any ideas?
    Reply With Quote
    Reply

    Bookmarks

    Thread Tools
    Display Modes


    Similar Threads for: Pressures, Case Strength and Back Thrust
    Thread Thread Starter Forum Replies Last Post
    FN action: BOLT THRUST REDUCTION Bigstrap3 Gunsmithing 10 05-12-2011 09:39 PM
    Vanguard Strength 270Weatherby Reloading 12 04-07-2011 11:24 AM
    Browning BAR strength elkhide Gun Parts - Stocks, Barrels, Actions, etc. 4 01-28-2011 11:42 AM
    Bolt thrust and case taper? jcoop Long Range Hunting & Shooting 3 11-21-2009 10:58 PM
    Redding Set Back Die Grows Case? dbhostler Equipment Discussions 8 01-07-2004 03:20 AM


    All times are GMT -5. The time now is 07:10 PM.


    Powered by vBulletin ©2000 - 2017, Jelsoft Enterprises Ltd.
    Content Management Powered by vBadvanced CMPS
    All content ©2010-2015 Long Range Hunting, LLC