Long Range Hunting Online Magazine


Go Back   Long Range Hunting Online Magazine > Hunting > Long Range Hunting & Shooting

Long Range Hunting & Shooting Nightforce Optics


Reply

Help with my long range shooting

 
LinkBack Thread Tools Display Modes
  #8  
Old 01-05-2012, 12:18 PM
Gold Member
 
Join Date: Jan 2009
Location: GSP, SC, USA
Posts: 629
Re: Help with my long range shooting

Quote:
Originally Posted by WildRose View Post
Good explanations above. I'll add to it however in that the very long VLD bullets are going to begin destabilizing at transonic speeds and the non VLD's with the shorter profile are going to suffer less destabilization at sub sonic speeds but give up accuracy while at super sonic speed vs the VLD designs.

Unfortunately no one has found a bullet that can reshape itself to perform at peak levels at both plus and sub sonic speeds.

A sub MOA weapon and load should be sub MOA at any range as long as the bullet remains super sonic, but after than it's going to open up.

Thanks for that explaination. Talking about just that point in the flight where conversion to sub sonic occurs I would like to learn what we (ya'll) know as to what the good-bad & the ugly is if you are shooting rounds that have: (i.e. something like this..... a FB will be more accurate up to that point, but at that point it will go to hell in a skinny nanosecond...bla..bla ...what ever. Or the opposite...what ever. Even if you can't prove what you believe at that point in the flight please give your best guess, you have been there and I have not.....please I know some of you have gotten into some of these areas. I am wanting to be a spounge on this stuff just because alot of us can learn something from your tests. It might allow us to make a better GUESS which bullet to use in certain situations.
A) FB......

B) BT......

C) RBT......

D) VLD & any thing else......

Thank you for your support. {:>)
__________________
Son, The first shot is the important one - the others just make him run faster! Grandpa 1949
NRA Life Member 1970
Reply With Quote
  #9  
Old 01-05-2012, 02:13 PM
Silver Member
 
Join Date: Oct 2008
Location: pa
Posts: 385
Re: Help with my long range shooting

I dont know about all that, but I have been shooting the 300 blkout and testing my own supersonic and subsonic loads and it seems not to have the same reaction as you stated when I get above 1150 fps or so an when they reach my target at 100yds an by then they sure slowed down a bit , they have not keyholed or destabilized ... I cant explain this ..? Could it be the distance ?
Reply With Quote
  #10  
Old 01-05-2012, 03:36 PM
Silver Member
 
Join Date: Jun 2009
Location: Bedford PA
Posts: 286
Re: Help with my long range shooting

I would say that it is the distance. Let's use a spinning top for an example. Once you initially spin it, the top wobbles momentarily then stabilizes (this would be the yaw) after the bullet reaches its maximum distance (remember the top) the destabilization begins to occur. which is similar to the yaw once created outside of the barrel. This explains why heavier bullets sometimes shoot better at longer distances. Also this is why it's important to have the correct spin on the bullet.

To summarize things, once the bullet goes subsonic at extended distances variables affect accuracy at a higher degree when the projectile is running out of steam. That's why VLD bullets tend to do better down range.
__________________
My final authority in all matters of faith and practice is the King James Bible. It's still the monarch of books!!
Reply With Quote
  #11  
Old 01-05-2012, 03:57 PM
Platinum Member
 
Join Date: Feb 2011
Location: Halfway between Lubbock and Dallas
Posts: 5,140
Re: Help with my long range shooting

Quote:
Originally Posted by T3-OleMan View Post
Thanks for that explaination. Talking about just that point in the flight where conversion to sub sonic occurs I would like to learn what we (ya'll) know as to what the good-bad & the ugly is if you are shooting rounds that have: (i.e. something like this..... a FB will be more accurate up to that point, but at that point it will go to hell in a skinny nanosecond...bla..bla ...what ever. Or the opposite...what ever. Even if you can't prove what you believe at that point in the flight please give your best guess, you have been there and I have not.....please I know some of you have gotten into some of these areas. I am wanting to be a spounge on this stuff just because alot of us can learn something from your tests. It might allow us to make a better GUESS which bullet to use in certain situations.
A) FB......

B) BT......

C) RBT......

D) VLD & any thing else......

Thank you for your support. {:>)
Mainly it has to do with the front half of the bullet.

At SS speeds the bullet is piercing the air and traveling within a vacum created by the sonic wave generated by the tip. The long thin VLD design allows those bullets to maintain super sonic speeds and stability longer than the more blunted non VLD designs.

At sub sonic speeds lift characteristics come into play.

It's the same reason that early generation super sonic fighters had serious problems at sub sonic speeds. In order to achieve the greatest possible speeds the wings were shortened and swept back in a sharp V design and made ultra thin so as to reduce drag.

Conversely low speed aircraft have a much greater wing area and the wings are straighter giving them much more air to work with.

Many of the early SS fighter prototypes did fine as long as they were accelerating o0r cruizing above the speed of sound but destabilized often to the point of no longer being controllable as they tried to slow back to sub sonic speeds for maneuvering and landing.

Today we get around that with planes that can change the angle of the wings and or make use of flaps for greater maneuverability and stability at low speed.

I'm not a physicist or an engineer so I can't do a very good job of explaining it but I understand the basic principles involved and have seen the results.

Google Bullet design and VLD bullet design and you can find some good articles on the subject.
__________________
Without the First and Second Amendments the rest of The Constitution is Meaningless.
Reply With Quote
  #12  
Old 01-05-2012, 04:12 PM
Silver Member
 
Join Date: Oct 2008
Location: pa
Posts: 385
Re: Help with my long range shooting

Complicated but I see what your saying for a bullet fired from a great distance, but would that would mean my 1100 fps 220gr SMK bullet fired from my 300 blackout should destablize as soon as it leaves the barrel ? Even at 200 yards its still maintaining a decent 3 inch group . This has me questioning things ?
Reply With Quote
  #13  
Old 01-05-2012, 04:20 PM
Silver Member
 
Join Date: Jun 2009
Location: Bedford PA
Posts: 286
Re: Help with my long range shooting

Not necessarily, the bullet you're using has a consistent pattern to it. At that velocity it doesn't see extreme variances. You could use a 22 for example and the results would be similar.
You take an object and spin it at several hundred thousand rpm's. When it slows there's nothing to contain the energy so it will wobble or tumble.
__________________
My final authority in all matters of faith and practice is the King James Bible. It's still the monarch of books!!
Reply With Quote
  #14  
Old 01-05-2012, 04:20 PM
Platinum Member
 
Join Date: Feb 2011
Location: Halfway between Lubbock and Dallas
Posts: 5,140
Re: Help with my long range shooting

Quote:
Originally Posted by snowpro440 View Post
Complicated but I see what your saying for a bullet fired from a great distance, but would that would mean my 1100 fps 220gr SMK bullet fired from my 300 blackout should destablize as soon as it leaves the barrel ? Even at 200 yards its still maintaining a decent 3 inch group . This has me questioning things ?
No your SMK is not a VLD and it's never exceeding SS speed therefore that transition that happens as the shock wave begins to collapse never occurs.

It is a BTHP but not a VLD, it has a much shorter and thicker profile than a VLD of similar diameter and weight.

Compare photos of the SMK and a Lapua Scenar or Berger VLD and you'll see what I mean.
__________________
Without the First and Second Amendments the rest of The Constitution is Meaningless.
Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes


Similar Threads for: Help with my long range shooting
Thread Thread Starter Forum Replies Last Post
Hello everyone, new to long range shooting dstewart51 Member Introductions 8 11-10-2012 03:26 PM
Long Range Shooting Video & Shooting Simulation dariuszczyszczon Long Range Hunting & Shooting 11 04-02-2012 08:41 PM
New to long range shooting huntintales Long Range Hunting & Shooting 25 12-21-2011 08:28 PM
long range shooting w/.243? DanielLudwig Rifles, Bullets, Barrels & Ballistics 11 06-02-2010 04:55 PM


All times are GMT -5. The time now is 06:26 PM.


Powered by vBulletin ©2000 - 2014, Jelsoft Enterprises Ltd.
Content Management Powered by vBadvanced CMPS
All content ©2010-2014 Long Range Hunting, LLC