load help ?

[zeke]

Metal God-It is not my theory. Bullets spin around an axis, and there can be differing degrees of stabilization. Longer bullets can require faster twists. While some may not agree with what actually happens, google yaw effect on bullet stability. Please notice i did not say the bullet completely destabilizes. While had read about this in years past, did not pay attention till it actually happened. When i see things, i usually believe them.

It is not a regular occurrence, and i can shoot well enough off a bench with an target rifle to tell the difference. Am not prone to postulating on the internet, and the majority of what am posting is from actual experience.

When experimenting with bullets , am like most everyone else and use 100 yards to start checking for precision. Over 99% of the time the moa increases proportional at increasing distance, until other affects come into play. Am not spending much time at a 100 yd bench anymore, and transitioning to shooting off the ground. If wanting to test a loads true potential at 100 yards, will shoot at a cross that matches the subtension on the particular scopes reticle.

After experiencing what happened with the 175 sierra tmk, switched to the 168 grain version. The 168 grain version is as precise at 100, as it is further out. The sig ssg 3000 allows the bullet to be seated out further than max col, which allows increase in powder to maintain the velocity. Using a bipod and rear bag, it is a very accurate combination.
Unfortunately the local range only goes out to 600 yds.

For your assumptions about what is happening to be true, i would be experiencing this on a common basis.

 

[zeke]

younz might be in trouble if i can actually figure out attaching pics
168 sierra tmk with 748, 600 yds off bench with bipod/rear bag no wind from sig ssg 3000

 

[hounddawg]

Please provide a link to where I can buy the bullets that group smaller the farther out that I shoot them. I'll start with a thousand in .264, a thousand in .223, and another thousand in .243

 

[USSR]

Please provide a link to where I can buy the bullets that group smaller the farther out that I shoot them.

Ditto. Never found it to be the case when I was shooting out to 1,000 yards.

Don

 

[zeke]

Never said the accuracy kept improving past where the bullet was fully stabilized. But golly gee wilikers, you're on to the black helicopter plot to start a business selling magic bullets. if ya really want some magic bullets, bet someone will sell ya some.

 

[5whiskey]

I will chime in to Zeke's support. It may be a rare phenomena, but I have a load/rifle combo that does shoot better with distance. 130gn Sierra Gamekings over 52 grains of Win760/H414 will shoot 5 rounds into about .9" (rather consistent group sizes as well) at 100 yards. The same rifle will do 2" 5 round groups at 300 yards consistently (More like 2.1" but I like easy math). The rifle goes from approximately .9moa to .66moa over distance. At around 500 yards, it's goes back up to around .8moa (4" groups during calm conditions, most of the time, but I digress that I am less consistent as environmental factors begin to come in play much more). I cannot explain why this rifle/load does this. Neither can Brian Litz at Applied Ballistics, who wrote an article (link to location of article below) in an effort to explain it with Epicyclic Swerve. In the end he concluded that Epicyclic Swerve did not explain the phenomena, but that he has personally observed the phenomena in real life.

http://appliedballisticsllc.com/ballistics-educational-resources/articles/

Scroll down to the article on Epicyclic Swerve. Again, the ultimate conclusion is that he states that he disproved the theory.

 

[cw308]

rebs
Both your rifles should be tack drivers from 1 - 300 yards , I try to give good advice , your shooting two rifles , I'm a one rifle guy been shooting my rifle for 10+ years . I'm so comfortable behind my rifle at this point things come so natural , changing back and forth from one rifle to the other are two different feels . Would you think to concentrate on one rifle at at time , as you know both rifles won't shoot the same with the same reload . I would start with the recommended OAL listed for the bullet used and just work on powder charge . Then once you found the best charge that groups the tightest , then tweak OAL and see if things improve . All at 100 yards . Then when you move longer you see how form makes a big difference . You have to settle down behind your rifle , when your set its like a well fitting puzzle , hard to explain a feeling . S _ _ t this sounds like a love story , sorry .

 

[HiBC]

zeke: Unclenick fed me an eye opener a while back.It was about 3 round sight in groups.Point is,we might jump to conclusions from small round counts.

I can believe a barrel has a cone of dispersion that we might measure in terms of MOA. I can agree that bullet stability or "going to sleep" can have an effect on the rate accuracy deteriorates ,but I cannot understand how the MOA of dispersion can get smaller at longer ranges.

It can get larger easy.A group dispersiom can head off in any direction,360 degrees.Random scattering.

But in order for MOA to improve at longer ranges,the bullet can only "disperse" back to the point of aim.Unless this bullet has a guidance system like a TOW missile,the bullet has no intelligence to know where the center of the target is.
What I CAN believe is optics may be a factor.The parallax error might be better (less) at 300 than it is at 100.Or,maybe the same SIZE bullseye appears smaller at longer ranges.Aim small,miss small.

To compensate for range the only variable I want to work with is sighting.

That might be hold,whether Kentucky windage or BDC reticle,or it might be twisting knobs.


Or,I might optimize my sight in and trajectory to pretty much hold on and shoot (MPBR)

 

[rebs]

cw38 your right I should be concentrating on one rifle instead of working with two and getting no where

 

[zeke]

HiBC-At no time did i indicate the experience was based on a single 3 shot group. The group pictured was not from the 175 grain load. Am glad you have been able gain something from this forum in regards to basing knowledge on a single 3 shot group. Perhaps someday you might experience what is being referred to.

Read the posts again, and perhaps google up bullet yaw. Bullet rotation, and yaw (minute) occur while the bullet is on a trajectory. The slight yaw of a bullet does not send it off in another direction. The bullets were still grouping (at a size likely acceptable to many), but not to the standard the rifle is capable of.

I do not know the exact physics behind it, but the analogy of the bullet flying off in a differing direction is so far off base as to not warrant further response.

https://www.youtube.com/watch?v=4pF8W5liSRc

 

[cw308]

rebs
I wouldn't say no where , your just making harder on yourself . You know more then most , hang in there.

PS are you checking parallax , sorry just wanted to be sure.

Chris

 

[Metal god]

I may be misunderstanding what you are saying so I'll give it another try . Are you saying you have a load that shoots a consistent 1moa or worse group at 100yds but also shoots a consistent 1/2 or 3/4moa groups at 300yds ? I don't mean consistent 1moa group at 100yds and once and awhile it shoots 3/4moa group at 300 . It needs to shoot NO better then 1moa at 100yds and almost always shoot smaller groups 300yds or further ??? If not it's just the stars aligning sometimes allowing you to shoot the tighter group .

Example : here are two targets at 300yds

This first one is a .33moa group from a load that almost never shoots that at 100yds . Thing is , It almost never shoots that at 300 either .

Here's another target I shot at 300yds with a 3 shot group of 1/2moa . Again this is a 5/8 to 3/4 moa load at 100yds most of the time . This is the only under 5/8moa group I've ever shot at 300yds with this load . I'll add this group IMHO is way better then the one above even though it's larger . That's because it was windy that day and each shot had a different POA but still had the same POI on target . The other target was a calm day and I just aimed at the center dot .

My point , at least for me . Just because I have shot a smaller group at distance then I have at 100yds does not mean that's what that load is likely to do at distance consistently . In fact if you are looking to shoot small groups at 500yds plus . Your POA is likely going to be slightly different every shot . Which makes it hard to say the load shot a smaller group if your POA was different each shot like I did in that second pic Which none of my POA were actually on the target .

FWIW the firearm is a 308 Savage model 10 . Two different loads , top target is 190gr smk and N-540 . lower target is 178gr A-max and IMR-4064 .

 

[Pathfinder45]

I would agree with those that say it's not possible for a rifle to shoot the same ammo better at 300 yards than it can at 100.... if I had not experienced it myself. We have hashed this out more than once before here at TFL.... While this may be an unusual occurrance, it is clearly not rare. My 270 is accurate enough at 100 yards to do the job, but I have yet to find a single recipe that will put 5 rounds into an inch. The best it has ever done is 1.25" for 5 shots at that range. At 300 yards, most of those better recipes go all over the paper, many five shot groups are well over a foot. A lot of you would get rid of this rifle....but get this: A certain load recipe that will only make 1.5 inches for five shots at 100 yards will consistently place 5 into 2.5" or less, at 300 yards. It would seem that somewhere in the flight-path of the bullets, stability improves to the point where the dispersion decreases or stops altogether as the bullets paths continue on in a more nearly parallel manner. I may not fully understand it, but I know it's happening.
If some of us don't believe this is possible, it's because their rifles probably don't do this. Some rifles, like people and horses, can have vices. I could probably cure my rifle by floating the barrel and bedding the action, but it shoots so darn well with a few loads that I am loathe to change anything.

 

[rebs]

cw308
Thank you for your help and advice. You gave me the best advice I could receive, one rifle at a time. I have been dealing with too many variables and have been shooting at too many different ranges, 50, 100, 200 and 300 yds. I am going to follow what you said and do my load development all at 100 yds.
I have had trouble with adjusting parallax, what is your procedure for setting parallax ? The scopes I use are a Nikon prostaff 5 with side focus and a Leupold with an adjustable objective.
I appreciate your help.

 

[zeke]

Pathfinder-Had never seen the video attached in my last post before, but bullet pitch and yaw are real. The video appears to represent the effects of it. What some are experiencing just appears to be this occurring to a more significant extent than what the video demonstrates. Belief most every rifle bullet goes through this yawing, even combinations we deem fully "stabilized". It is just to such a small extent to not be noticeable.

So at one extreme we have this yaw happening that we never notice. I do not consider this a "theory", but factual. At the other extreme we have bullets so unstabilized they tumble at 50 yards. Again this is not a "theory", but factual. Without being able to prove it at all, logic tells me they are differing stages of this occurrence in between the two extremes. Likely related to how differing length of bullets react to differing rifling twists, barrel lengths and load combinations. Am also of belief this becomes more noticeable as other factors affecting accuracy are minimized/controlled.

 

[David R]

zeke, I get it. The bullet travels like a cork screw then settles down in a straight path.

Never happened to me, but makes total sense.

Rebs, keep at it.

David

 

[hounddawg]

Zeke you are the one with the magic bullet idea I thought maybe you had some for sale. In the real world the divergence from point of aim will continue to infinity unless some outside force acts on a bullet in flight, ie gravity and wind

here is a thread on accurate shooter by Bryan Litz discussing this back in 2015

http://forum.accurateshooter.com/threads/applied-ballistics-shoot-thru-target-challenge.3861880/

and post 9 of this thread shows why even Bryan Litz can have a oopsie

http://forum.accurateshooter.com/threads/bullet-dispersion.3863237/

 

[cw308]

rebs
If your having alittle trouble setting up your parallax , that could be most of your problem . Start with adjusting your parallax on your scope to the distance your shooting . Then setup behind your rifle , cheekweld , proper eye relief then when looking through your scope cross hairs fixed on bullseye , slightly move your head up and down and side to side to see if cross hairs shift off bullseye , you will see movement but cross hairs will stay fixed on target . Then your parallax is correct . Most scopes are very close to good so very little adjustment is needed . Just make sure your cross hairs don't drift as you make very slight movements with your head , that's when you know parallax is off.

PS What is your setup at the bench meaning rear bag , bi pod , front rest or sand bags , also where positioned on front rest . Not on barrel.

 

[5whiskey]

Zeke you are the one with the magic bullet idea I thought maybe you had some for sale. In the real world the divergence from point of aim will continue to infinity unless some outside force acts on a bullet in flight, ie gravity and wind

here is a thread on accurate shooter by Bryan Litz discussing this back in 2015...

Houndawg, I read that thread and I am going to try the experiment outlined on accurate shooter since I have a rifle/load that appears to shoot convergent groups. I'll post my findings, and I guess will find out if it's a real phenomena or if I just tend to shoot better at further targets because of parallax, concentration, or whatever other reason. Groups are consistent enough that I'm inclined to not believe it's in my head, but we will see.

 

[zeke]

houndawg-thanks for the article, but this discussion is not about an individual rifle being able to shoot smaller angular groups at increasingly longer distances. It is about bullets shooting smaller MOA if they become more stabile at longer distances where this change can be observed before other factors affect the path more. Nowhere (that i am aware of) has anyone who experienced this occurrence related it to a single rifle, or implied the groups continue to get smaller at ever increasing distances after the bullet stabilizes. As you well know, their is no "magic bullet" People wanting to discuss Berger's simulation should take it up with the producers of the video.

From the linked article:
"Furthermore on this theory; Lets assume for a moment that the bullet really is flying a corkscrew flight path of constant, or diminishing magnitude. In order for the groups to be angularly bigger at shorter range would *require* that the bullets always passed thru the 100 yard target on the OUTER edge of their orbit, and pass thru the longer range target on the INNER edge of their orbit."

I could not "guess" if this is required, but certainly possible. My initial reaction to this statement is that the "orbit" is becoming smaller, as the Berger video simulates. And yes, it just be a simulation. And that the decrease in orbit is enough so that the outer edge of the decreased orbit is still less than the inner edge of the larger orbit. An yes the timing of a load combination could influence everything. For the vast majority of situations this does not occur.

Also don't believe this is regular occurrence, but related to combination of factors including the rifling twist and length of bullet. Not a specific "magic rifle/bullet" Certainly there are numerous other possibilities people have't thought of yet.

Would also expect that shortly in the future, someone will be able to actually use high speed video to capture the action of the bullet during a flight path in controlled conditions, while measured any deviations.

Thanks for the link, it helps. Was not aware of the various discussions held on this over the years. For my purposes will continue to check some loads that aren't quite up to snuff at longer distances. From a specific rifle, the Sierra 175 tmk carry's very well at distances available to me, but will stick to the 168 tmks for my experience with their combination of short/longer range capability.