close
Long Range Hunting Online Magazine


Go Back   Long Range Hunting Online Magazine > Rifles, Reloading, Optics, Equipment > Rifles, Bullets, Barrels & Ballistics

Rifles, Bullets, Barrels & Ballistics Applied Ballistics

Reply

Rotational velocity vs wound severity

LinkBack Thread Tools Display Modes
  #15  
Unread 10-26-2012, 09:40 PM
Platinum Member
 
Join Date: Dec 2009
Location: LaPine Or.
Posts: 2,536
Re: Rotational velocity vs wound severity

What if you throw in a gain twist barrel.....? There's a monkey wrench

Looking forward to seeing a baseline, & results of your testing.
__________________
"Its not Rocket Surgery.....'
GOD,GUNS,&GUTTS MADE AMERICA, LETS KEEP ALL 3!winmag

"I have No idea why that cop made me ride in the back seat, when I Clearly called Shotgun!"
Reply With Quote
  •   #16  
    Unread 10-26-2012, 09:57 PM
    Platinum Member
     
    Join Date: Dec 2008
    Location: rathdrum, id.
    Posts: 5,019
    Re: Rotational velocity vs wound severity

    Quote:
    Originally Posted by winmag View Post
    What if you throw in a gain twist barrel.....? There's a monkey wrench

    Looking forward to seeing a baseline, & results of your testing.
    That's a good one. Seriously though, the rotation is still whatever the velocity x twist is as the bullet leaves the barrel......Rich
    Reply With Quote

      #17  
    Unread 10-26-2012, 10:11 PM
    Platinum Member
     
    Join Date: Dec 2009
    Location: LaPine Or.
    Posts: 2,536
    Re: Rotational velocity vs wound severity

    Quote:
    Originally Posted by elkaholic View Post
    That's a good one. Seriously though, the rotation is still whatever the velocity x twist is as the bullet leaves the barrel......Rich
    Very true for rpm.

    However "IF" a tight twist tends to grind up lighter/shorter bullets, & a gain twist can sometimes "Ease" or "Aleviate" the grinding effects but still have a faster rpm at exit, there may be some Merritt to the jacket stress vs twist ratio. Hmmmm sounds too scientific not to be a monkey wrench hahahaha

    This is like rocket surgery... I love it
    __________________
    "Its not Rocket Surgery.....'
    GOD,GUNS,&GUTTS MADE AMERICA, LETS KEEP ALL 3!winmag

    "I have No idea why that cop made me ride in the back seat, when I Clearly called Shotgun!"
    Reply With Quote
      #18  
    Unread 10-26-2012, 10:16 PM
    Platinum Member
     
    Join Date: Dec 2008
    Location: rathdrum, id.
    Posts: 5,019
    Re: Rotational velocity vs wound severity

    Quote:
    Originally Posted by winmag View Post
    Very true for rpm.

    However "IF" a tight twist tends to grind up lighter/shorter bullets, & a gain twist can sometimes "Ease" or "Aleviate" the grinding effects but still have a faster rpm at exit, there may be some Merritt to the jacket stress vs twist ratio. Hmmmm sounds too scientific not to be a monkey wrench hahahaha

    This is like rocket surgery... I love it
    But gain twist also makes larger grooves in the jacket by virtue of the fact that that the angle changes as the bulllet progresses, which causes GREATER loss of jacket integrity........Rich
    Reply With Quote
      #19  
    Unread 10-26-2012, 10:18 PM
    Platinum Member
     
    Join Date: Apr 2012
    Location: The cold part of Montana
    Posts: 1,391
    Re: Rotational velocity vs wound severity

    The modified Point mass trajectory calc. includes rpm. It's neither linear or constant but the rpm loss seems to be about 20% over a 100yrds for a 168gr 7mm

    JBM - Calculations - Modified Point Mass Trajectory

    click on the link and then hit calc at the bottom
    __________________
    Keep in mind the animals we shoot for food and display are not bullet proof. Contrary to popular belief, they bleed and die just like they did a hundred years ago. Being competent with a given rifle is far more important than impressive ballistics and poor shootability. High velocity misses never put a steak in the freezer.

    Joe
    Reply With Quote
      #20  
    Unread 10-26-2012, 10:24 PM
    Platinum Member
     
    Join Date: Dec 2008
    Location: rathdrum, id.
    Posts: 5,019
    Re: Rotational velocity vs wound severity

    Quote:
    Originally Posted by Joe King View Post
    The modified Point mass trajectory calc. includes rpm. It's neither linear or constant but the rpm loss seems to be about 20% over a 100yrds for a 168gr 7mm

    JBM - Calculations - Modified Point Mass Trajectory

    click on the link and then hit calc at the bottom
    I'm only seeing about 2.3 % ??
    Reply With Quote
      #21  
    Unread 10-26-2012, 10:54 PM
    Platinum Member
     
    Join Date: Apr 2012
    Location: The cold part of Montana
    Posts: 1,391
    Re: Rotational velocity vs wound severity

    1000yrd rpm-166249
    Muzzle rpm-212793

    166249/212793=0.781

    1 - 0.781=0.219

    100%*0.219 =21.9%
    __________________
    Keep in mind the animals we shoot for food and display are not bullet proof. Contrary to popular belief, they bleed and die just like they did a hundred years ago. Being competent with a given rifle is far more important than impressive ballistics and poor shootability. High velocity misses never put a steak in the freezer.

    Joe
    Reply With Quote
    Reply

    Bookmarks

    Thread Tools
    Display Modes


    Similar Threads for: Rotational velocity vs wound severity
    Thread Thread Starter Forum Replies Last Post
    Treatment of primer explosion wound proload Reloading 31 09-11-2011 05:50 AM
    exit wound from 200grn Nosler accubond dmproske Rifles, Bullets, Barrels & Ballistics 5 11-09-2009 11:45 AM
    30-378 velocity SUNDEVIL Rifles, Bullets, Barrels & Ballistics 2 03-05-2008 07:57 PM
    exit wound stxhunter Long Range Hunting & Shooting 4 02-06-2008 05:47 PM
    Do you want a exit wound???? lerch Long Range Hunting & Shooting 81 07-03-2005 03:37 PM


    All times are GMT -5. The time now is 01:40 AM.


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