Bullet Design and Precession
Anyone want to give their thoughts on 'precession' and it's effect on bullet flight and design? (without spilling the beans on any proprietary info)
I spent a few too many hours w/ a group of Engineers/Physicist at a long range shooting clinic yesterday and my head is spinning as well as the projectiles!
Edit: Rufe, most of these engs and one Physics prof are rather new to shooting let alone @ long ranges.
The question of precession actually came up days before the clinic as one German Eng was unable to understand why he could shoot tight groups w/ his .357 Carbine and only shot large groups w/ the same rifle and .38 spls (same distance). It seemed like a simple 'speed, time distance' problem to me, but the Physicist insisted it was due to precession (which was new to me). I haven't seen the groups nor was at the range when this even happened.
I doubt the Professor understands the difference between a 38 spl and a 357 mag. He just recently asked me if he could shoot 270, 30-30 or 308 out of his 30-06, thinking they were just different in 'power' w/o understanding they are VERY different cartridges. It has been interesting on my end, to say the least.
Bob - Thanks for the link/info.
Mark C I'm right there w/ you! (but am willing to learn)
I know nononsense and others have designed VLD bullets and was hoping they'd wade in with some design info.
I spent a few too many hours w/ a group of Engineers/Physicist at a long range shooting clinic yesterday and my head is spinning as well as the projectiles!
Edit: Rufe, most of these engs and one Physics prof are rather new to shooting let alone @ long ranges.
The question of precession actually came up days before the clinic as one German Eng was unable to understand why he could shoot tight groups w/ his .357 Carbine and only shot large groups w/ the same rifle and .38 spls (same distance). It seemed like a simple 'speed, time distance' problem to me, but the Physicist insisted it was due to precession (which was new to me). I haven't seen the groups nor was at the range when this even happened.
I doubt the Professor understands the difference between a 38 spl and a 357 mag. He just recently asked me if he could shoot 270, 30-30 or 308 out of his 30-06, thinking they were just different in 'power' w/o understanding they are VERY different cartridges. It has been interesting on my end, to say the least.
Bob - Thanks for the link/info.
Mark C I'm right there w/ you! (but am willing to learn)
I know nononsense and others have designed VLD bullets and was hoping they'd wade in with some design info.
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quote:Originally posted by iceracerx
Anyone want to give their thoughts on 'precession' and it's effect on bullet flight and design? (without spilling the beans on any proprietary info)
I spent a few too many hours w/ a group of Engineers/Physicist at a long range shooting clinic yesterday and my head is spinning as well as the projectiles!
If a bunch of engineers and physicists don't know? Why do you expect a bunch of retards like us to know?0 -
When I am at the SHOT Show I steer well clear of the ballistics guys at the ammunition displays because I am in over my head within 30 seconds! 0 -
Arent engineer's, and physicists' similar to politicians????? 0 -
Here's some reading for you.
http://library.med.utah.edu/WebPath/TUTORIAL/GUNS/GUNBLST.html0 -
quote:Originally posted by babun
Here's some reading for you.
http://library.med.utah.edu/WebPath/TUTORIAL/GUNS/GUNBLST.html
Great illustrations of the physics of bullet flight!0 -
iceracerx,
I'm pretty sure you've read this little dissertation but I thought it might be a good time to post it again:
http://www.nennstiel-ruprecht.de/bullfly/
This is the illustration from the article noted in a previous post which shows the motion of the bullet in all three phases.
"Yaw refers to the rotation of the nose of the bullet away from the line of flight. Precession refers to rotation of the bullet around the center of mass. Nutation refers to small circular movement at the bullet tip. Yaw and precession decrease as the distance of the bullet from the barrel increases."
Best.0 -
nononsense - excellent illustrations! Thanks. 0 -
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Google books has "The Bullets Flight" by Dr. F.W. Mann as a free PDF download
Originally published in 1909, it is still considered the definitive work on external ballistics.
I'd loan you my hard copy (printed in 1942), but I'd worry about what a bunch of imagineers/physissies would do to a valuable reference book.
Edit That could probably be arranged, I'd just need to contact the land owner to tie down a date.0 -
quote:Originally posted by Tailgunner1954
D
Google books has "The Bullets Flight" by Dr. F.W. Mann as a free PDF download
Originally published in 1909, it is still considered the definitive work on external ballistics.
I'd loan you my hard copy (printed in 1942), but I'd worry about what a bunch of imagineers/physissies would do to a valuable reference book.
I believe I have a copy of that book but can't put my fingers on it (I looked for it to support my position but it's not where I thought it would be). At least I understand why the .223 shots better groups @ 100 than @ 50. It will be interesting to see what it can do @ 200 @ Ortonville (unless we can use your corn field?)0 -
Hello Nononsense This is what I think I was talking about on another topic about a cork screw . "Nutation" do you have any IDEA of how far say a 168 grain 30-06 would travel from the starting point at 6-OCLOCK to the 8-oclock one large diameter arc and almost one complete small circle.That is what I remembered seeing through my spotting scope with my rifle shooter shooting at 1000 yards in Hawaii. Thanks for any insight Karl. 0
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