Think you can explain it?

[DocUSMCRetired]

non-linear dispersion. What is it? How about an example. You fire a group at 100m and you group 1 MOA. That same group, groups 1/2 MOA at 300 yards. Join us for the discussion see if you can solve this ballistics anomaly!

http://www.longrangehunting.com/forums/f19/applied-ballistics-shoot-thru-target-challenge-144359/

 

[Unofficial Gun Addict (UGA)]

Hmmm... Well... Since I don't have a hi-speed slow mo camera that I can setup to verify what is really going on... Ill lay out two philosophies that I've heard.

1. Some bullets have not yet stabilized out to 100 yards, but settle into a groove somewhere between 150-200 yards, therefore groups that might be wider at 100, May settle down to smaller groups at distance.

2. People often times use the same sized targets at 100 yards as they do at further distances. Since the target is smaller at distance , more care is made to fire when crosshairs are on target, therefore, smaller groups.

In all candor... I just don't know, but I'd much rather have a group that tightens up with distance, as opposed to widens! gun)

 

[WildRose]

Hmmm... Well... Since I don't have a hi-speed slow mo camera that I can setup to verify what is really going on... Ill lay out two philosophies that I've heard.

1. Some bullets have not yet stabilized out to 100 yards, but settle into a groove somewhere between 150-200 yards, therefore groups that might be wider at 100, May settle down to smaller groups at distance.

2. People often times use the same sized targets at 100 yards as they do at further distances. Since the target is smaller at distance , more care is made to fire when crosshairs are on target, therefore, smaller groups.

In all candor... I just don't know, but I'd much rather have a group that tightens up with distance, as opposed to widens! gun)

I'd call those both pretty good shots at it.

 

[600BP]

I would venture to guess that if a three shot group, from the same rifle, maintains the one inch group from 100 out to 300 yards, it would actually be approximately 1/3MOA at 300, 1/2 MOA at 200, and 1 MOA at 100. But I could be way off the page from what is being asked.

Erik

 

[royinidaho]

A new term I learned last night is 'epicyclic swerve'.

I'll be using it a lot for awhile. I get a kick out of not knowing what I'm talkin' about. :roll eyes:

Epicyclic swerve will certainly impress the cowboys at the local leather shop hangout.gun)

 

[RMulhern]

Hmm...I say it's possibly caused by gyroscopic stability increasing as the projectile goes downrange!

 

[7magcreedmoor]

I have Litz's book, and understand maybe just enough of it to be a danger to myself and others now. Never shot a pass through target, but have seen better groups at longer distance with the same rifle and just figured I don't try as hard up close...
As long as I can keep it under "minute-of-venison" I'm gonna leave the science to Bryan.

 

[FearNoWind]

Well, based on what's posted here:

http://www.longrangehunting.com/forums/f17/think-you-can-explain-144418/

Hmm...I say it's possibly caused by gyroscopic stability increasing as the projectile goes downrange!

I'd say the discussion is pretty much over. A picture



is still worth a thousand words.

 

[DocUSMCRetired]

I wish it were that simple @FearNoWind. This is discussed thoroughly here http://www.appliedballisticsllc.com/Articles/ABDOC104_EpiciclicSwerve.pdf

What you are seeing there is a large representation of something that is very small (That motion is inside the same area as the caliber of the bullet.

 

[FearNoWind]

I wish it were that simple @FearNoWind. This is discussed thoroughly here http://www.appliedballisticsllc.com/Articles/ABDOC104_EpiciclicSwerve.pdf

What you are seeing there is a large representation of something that is very small (That motion is inside the same area as the caliber of the bullet.

Well, OK, Doc. Then perhaps it's not as simple as I had hoped. Thanks for clearing that up for me. Nevertheless, IMO, if the bullet meets the target where I want and expect it to, it's not all that important. I recall, during my long professional career, working with my staff to determine specific goals. I'd sign off on the goal, focus on the results, and not worry about how they got there as long as their methods were cost effective and ethical and the project remained on schedule. Never been interest in processes; only results. So I tend to look at life (and bullets) the same way. So far it's worked great. The bullet goes where I aim and the meat goes into the freezer. It's a beautiful thing. gun) ------------

 

[tmmcampbell]

Everyone knows the bullets have devils on them and the longer they spin the more likely they are to fall off. This has been common knowledge since the 1700s.

 

[7magcreedmoor]

Everyone knows the bullets have devils on them and the longer they spin the more likely they are to fall off. This has been common knowledge since the 1700s.

Thats awesome!

 

[CB11WYO]

...As long as I can keep it under "minute-of-venison" I'm gonna leave the science to Bryan.

Safe bet

 

[crowsnest2002]

After reading Applied Ballistics it was stated that it could be the optics or just shooter error if not shooting 3 rounds through two sets of paper one at 100m and then traveling through to the secondary target.