bullet grouping question @ 100 and 300 yards?????

skeetlee

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I am reading a post over on predator master were some guys are arguing that a vld bullet can in fact not shoot all that great of a group at 100yards but shoot a great group at 300 or even further. One guy refers to the bullet as going to sleep, and once it does this it will shoot better. I have personally seen this happen in one of my rifles, but is this the norm? Is it common for a vld to shoot better at longer ranges? I think so but what's the truth? In my mind the VLD bullets are made for long distance shooting, just as a flat base bullet is meant for closer ranges???? Whats the scoop? Lee
 

our gang

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Re: bullet grouping question @ 100 and 300 yards?????

I have had this experience in my 22-06 shooting 80 gr SMks.
For hunting purposes at normal ranges boattails are not needed but for long distance target work they do come into their own.
 

dontstrokeme

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Re: bullet grouping question @ 100 and 300 yards?????

Somthing along the lines of the vibration/harmonics that the barrel recieves from the explosion translates to the bullet....once the spin of the bullet stabalizes it back out it it can hold it's path better?

Seems like I read somthing about that in Understanding Firearm Ballistics book.....but maybe not, but it lines things up in my mind.
 

hunter223

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Re: bullet grouping question @ 100 and 300 yards?????

Ummm, going to sleep? not sure about that. I shot a 5 shot group out of my GAP 6.5 Creedmoor at 100yds the was one hole, not a ragged hole a pretty clean ONE hole group didn't measure it just admired it with one of my friends. so yeah VLDs can shoot ridiculously well @ 100 yds
 

cyberpuppy42

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Re: bullet grouping question @ 100 and 300 yards?????

A lot of what you're describing sounds like over-stabilization of the bullet as it initially comes out of the barrel. I suppose the common term is 'falling asleep', but I hadn't heard that one before.

It's difficult to get a bullet perfectly stable across the entire range of velocities as it slows down (i.e. to remain perfectly tangential to the bullet path at all times). You can get this perfect stability by matching the bullet to it's design muzzle velocity and spin rate. Shooting a bullet too fast for it's design spin rate will cause it to be over-stabilized, and so it has to slow down a bit before it catches up with its trajectory shape. That takes a few hundred yards, so in those cases you'll see some added noise in your groups at closer ranges. My .50 BMG AMAX bullets have that behavior, which is why I sight my rifle at 300 yards as opposed to 100 yards.

Think about a spinning top. When you spin it really fast, it wobbles around a bunch at first, then once it slows down it becomes really nice and clean, then it completely falls apart once it slows down too much. Same exact effect happens with a bullet.
 

GorbashUK

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Re: bullet grouping question @ 100 and 300 yards?????

Using my TRG22 and smk loads, i find they hold 0.5 moa at 100m, over 1 moa at 200m and the back to 0.5 moa at 300m. I cannot get my gun load combo to group well at 200m, it was driving me nuts until a friend shooting the same rig found a similar problem. There is more to this than meets the eye.
 

steve123

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Re: bullet grouping question @ 100 and 300 yards?????

Hi Lee,

I've experienced this phenomenon with a more than a few rifles with HPBT bullets or vld/uld solids throughout the years.For instance my 375CT shoots as good at 400Y as it does at 200Y.

Does one have to have hollow point boat tail vld's to effectively shoot long range ? I think not!The new 10 shot 1000Y benchrest record was just shot with 30cal flat base bullets.

Steve
 

ChadTRG42

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Re: bullet grouping question @ 100 and 300 yards?????

You typically have this problem with heavy/long for caliber bullets. With the 208 A-max in a 308 Win, and in my 300 WM, shooting groups at 100 yards was not the true accuracy of the load. I was able to get a .29" 5 shot group, but it would open way up at 300 and out. Once I did the load work up at 300 yards, the load shot good at distance. The same load shot so so at 100 yards, and shot awesome at 300. When a bullet exits the barrel, it will have some yaw to it. The longer bullets take a little longer to fully stabilize, or "go to sleep".
 

eddybo

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Re: bullet grouping question @ 100 and 300 yards?????

This is an old debate that I have read a bit on. Some will claim that bullets are stupid and once they leave their course can never come back to the intended path. I think it is very possible as I have experienced it several times. The only way I can reconcile this in my mind is to imagine the bullet orbiting around its path, like water rushing around a drain.
 

mbandy13

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Re: bullet grouping question @ 100 and 300 yards?????

If you do your load work up properly you should put the bullet to sleep coming out of the barrel. Most people want to push them too fast so just like what cyberpuppy was explaining with the top, it needs time to settle down, but if you find or know the proper speed for that bullet, (there are a number of speeds that will do it) you can get it to be stable exiting the barrel. This in my opinion is where a high quality chronograph is worth its weight in gold.

mike
 

USMCj

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Re: bullet grouping question @ 100 and 300 yards?????

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BOLTRIPPER</div><div class="ubbcode-body">......i'm sleepy now..... </div></div>

coffee.jpg
 

lemmethink

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Re: bullet grouping question @ 100 and 300 yards?????

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: USMCj</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BOLTRIPPER</div><div class="ubbcode-body">......i'm sleepy now..... </div></div>

coffee.jpg
</div></div>


MORE COFFEE!!!

I have observed this myself with a load that seemed to shoot better at 400 yards than at 100 yards and had read about this effect. Thinking about the top analogy it makes more sense now why this might occur.

 

skeetlee

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Re: bullet grouping question @ 100 and 300 yards?????

This wasn't my post over on predator master but it did get a bit out of hand (not on my part). I pretty much knew that this can happen as i had said i have experienced it. One guy called another a Moron. Pretty basic behavior over there. I just thought i would ask the same question over here were the people actually shoot past 100 yards. I am going to try and link this post over to predator master if i can figure out how to do it. I havent been able to link before. Thanks guys i will share the info. Lee
 

Maciej

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Re: bullet grouping question @ 100 and 300 yards?????

Although I don't know the engineering behind it, I think it'd be very possible that due to its low drag it might take a little bit more to fully stabilize, but I could be terribly wrong.
 

Pain_doc

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Re: bullet grouping question @ 100 and 300 yards?????

Chad and Cyberpuppy gave pretty good explanations. I've had it happen with a couple rifles/loads and so like Chad mentioned, I test most of my loads at least out to 300 prior to deciding that it's the "best". I've noticed that the results at 300 translate pretty well through the rest of the ranges out to 1000 for my 300wm/300wsm/7mmWSM. I've had a few people ask about it over the years, and I like the spinning top analogy. Usually, I've asked them if they've ever seen a quarterback throw a pass that started with a little wobble on the release, then seemed to "pick up" a tight spiral...and conversely if they've seen a long pass that was a tight spiral travel most of its distance, but then seem to just start to wobble and drop like a rock at the end. Most say yes, and then they report that they kind of have a good "mental picture" in their head to work from.
 

sailhertoo

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Re: bullet grouping question @ 100 and 300 yards?????

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: a-train</div><div class="ubbcode-body">Chad and Cyberpuppy gave pretty good explanations. I've had it happen with a couple rifles/loads and so like Chad mentioned, I test most of my loads at least out to 300 prior to deciding that it's the "best". I've noticed that the results at 300 translate pretty well through the rest of the ranges out to 1000 for my 300wm/300wsm/7mmWSM. I've had a few people ask about it over the years, and I like the spinning top analogy. Usually, I've asked them if they've ever seen a quarterback throw a pass that started with a little wobble on the release, then seemed to "pick up" a tight spiral...and conversely if they've seen a long pass that was a tight spiral travel most of its distance, but then seem to just start to wobble and drop like a rock at the end. Most say yes, and then they report that they kind of have a good "mental picture" in their head to work from. </div></div>

Good analogy.
 

BLAWTON

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Re: bullet grouping question @ 100 and 300 yards??

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: a-train</div><div class="ubbcode-body">Chad and Cyberpuppy gave pretty good explanations. I've had it happen with a couple rifles/loads and so like Chad mentioned, I test most of my loads at least out to 300 prior to deciding that it's the "best". I've noticed that the results at 300 translate pretty well through the rest of the ranges out to 1000 for my 300wm/300wsm/7mmWSM. I've had a few people ask about it over the years, and I like the spinning top analogy. Usually, I've asked them if they've ever seen a quarterback throw a pass that started with a little wobble on the release, then seemed to "pick up" a tight spiral...and conversely if they've seen a long pass that was a tight spiral travel most of its distance, but then seem to just start to wobble and drop like a rock at the end. Most say yes, and then they report that they kind of have a good "mental picture" in their head to work from. </div></div>


I work my loads up for 1k BR at 300-500 yards. I dont want the varibles you get a 1k to affect my loading decisions. I dont shoot as close at 100 because this can happen alot and even worse with the super heavy for caliber bullets. You need to give it a little travel before you can judge well what its gonna do further. The bullet get to a hundred yards to fast to be able to tell what it gonna do at a distance.
 

Timberwolf

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Re: bullet grouping question @ 100 and 300 yards??

I've had it go both ways in my rifle (.308 w/ 1:10 Rock 5R barrel). What I strive for is a load that holds stable (almost) from 100 to 1000. I tried to work up 155 scenars once and could at best get only around 1MOA at 100 but at 300 it hovered around .5 MOA. On the flip side I have a killer 1 ragged hole 168 load that goes litterally to shit past 300. My present load (178 AMAX) holds between .5 and .75 at 100; .75 to 1.0 at 300; and back to around .6 - .8 (if I do my part and the wind gods have been appeased) at 1000.
 

sandwarrior

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Re: bullet grouping question @ 100 and 300 yards??

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: mbandy13</div><div class="ubbcode-body">If you do your load work up properly you should put the bullet to sleep coming out of the barrel. Most people want to push them too fast so just like what cyberpuppy was explaining with the top, it needs time to settle down, but if you find or know the proper speed for that bullet, (there are a number of speeds that will do it) you can get it to be stable exiting the barrel. This in my opinion is where a high quality chronograph is worth its weight in gold.

mike</div></div>

BINGO!

As noted long for caliber bullets have some harmonic nodes that you have to get in tune with to not have the bullet yawing as it comes out the barrel. Yawing is caused by gyroscopic precession. Which, like on a top that cyberpuppy described, when having a force applied to it (vibration from the barrel) reacts 90 degrees from the point of contact. It also reacts about the lateral and yaw axis. The bullet has three axis, longitudinal, lateral and yaw In a rotating bullet lateral and yaw are the same thing. So truly two axis. So what is happening is the nose and base of the bullet are rotating in circles around the center of rotation of the spinning bullet. To make matters worse the wind deflection is also adding to the initial yawing of the bullet. Once the bullet stabilizes and rotates directly around the longitudinal axis it will begin to move through the air more efficiently. The only thing that stabilizes the bullet is the energy causing it to rotate. Eventually, that energy overcomes the yaw factor and the thus the wind deflection. Sometimes wind deflection even counters yaw(due to harmonics), and the bullet stabilizes sooner. But due to all this yes you can have a bullet shoot average to poor @ 100 yds. and shoot great @ 300. I will say though I've never seen a group from a rifle/ammuntion standpoint that ever shot tighter actual groups @ 300 than 100. I've shot 1 1/4 groups with the same load @ 100 and 300. But, I've never shot 2" @ 100 then turn around and shoot 1" @ 300. At least unless I knew why I screwed up.
 

RH4540

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Re: bullet grouping question @ 100 and 300 yards??

I don't know all the science behind it, but, yes, it happens. I have two loads for one of my .223s that barely make an inch at 100 yards, but, at 200 yards, the groups shrink to 5/8".
 

sniper7mm

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Re: bullet grouping question @ 100 and 300 yards??

I saw this in my buddys AR this past weekend. He was shooting 69 grain Match kings @ 100 yds. It was grouping right around an inch. He was going to give up on that load but decided to shoot a couple groups @ 300 first. It shot almost as good @ 300 as it did @ 100
One of the groups @ 300 was only 1-1/4 inch for 5 rounds.
 

jwfrazier

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Re: bullet grouping question @ 100 and 300 yards??

My LTR .308 usually shoots better at 300-400yds than it does at 100yds with 168gr. SMK. By this I mean smaller MOA wise, not actually smaller groups.
 

Greg Langelius *

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Re: bullet grouping question @ 100 and 300 yards??

Not all group 'shrinkage' related to distance increase is due to ballistic effects.

Some of it can be attributed to optics issues associated with parallax.

This is especially true if the groups tend to 'hourglass', being significantly smaller, MOA-wise, at a given distance, than distances both shorter and longer, with the 'choke' distance often being around 200yd, which is the distance most chosen by scope factories for optimizing parallax compensation.

When I test loads, I do them at 100yd, to reduce wind deflection consequences, and then at the intended distance(s) to 'proof' the loads for their intended use.

I pay a lot of attention to correcting parallax, and really don't see as much group MOA variations at varying distances as I see being discussed on the forums.

Greg
 

Graham

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Re: bullet grouping question @ 100 and 300 yards??

Here's my understanding of it:

VLD's shoot better at longer ranges because of better bullet quality and because they resist wind better due to the higher BC. But, in general, they fly worse: Bullets with a longer bearing surface have more engagement with the lands and take more force to push through the bore. Also, a longer bearing surface means a shorter nose for the same weight, and a shorter nose makes the bullet more susceptible to being tipped in flight.

All bullets travel (spin plus distance) in a wobbly (corkscrew) pattern. Putting a bullet to 'to sleep' means fully stabilizing it: the least wobble. Sometimes a good load at 100 will go bad at 300. Rarely will a bad load get better, because a good load that goes bad at distance is the result of small flaws in the group magnifying with the increased range.

I've heard people say that 'a bad VLD group at 100 can become a great group at 600'. I doubt it. It's true that VLD's are not designed to shoot well at 100 - meaning they won't shoot as well at short range as flat based bullets will in slower twist barrels - but we should be careful about how much we extrapolate beyond that. A VLD load that groups 1.5 MOA at 100, and 1.5 MOA at 300, that I would believe. But a 1 MOA load at 300 won't become a .5 MOA load at 600.

You should not avoid developing a good, accurate load with VLD's that shoots well at 300. In my experience, if it shoots well at 100 it's a crapshoot at 300. If it shoots well at 300, it will probably shoot well to 600 or so. But if it sucks at 200, forget it, it won't get better.

With VLD's it's a design issue: they are not DESIGNED to shoot well at short range - but they can. Speed is key, and VLD's like to go fast, but if the barrel twist won't stabilize it at a safe speed a higher speed probably won't help. Here is a VLD load that will do .5 MOA at 100 and maintain 1 MOA to 1000. Note that it is also slapped-together as Mexican match:

500m223.jpg
 

buckythebrewer

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Re: bullet grouping question @ 100 and 300 yards??

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Greg Langelius *</div><div class="ubbcode-body">Not all group 'shrinkage' related to distance increase is due to ballistic effects.

Some of it can be attributed to optics issues associated with parallax.

This is especially true if the groups tend to 'hourglass', being significantly smaller, MOA-wise, at a given distance, than distances both shorter and longer, with the 'choke' distance often being around 200yd, which is the distance most chosen by scope factories for optimizing parallax compensation.

Greg </div></div>
+1
I have experienced this more than once.I think this effect can be amplified when your using higher magnification too,,Am I correct?

It seems when using lower magnification I can sometimes shoot better(at the same range) and was wondering if the reason for this could have something to do with this topic.
Maybe its just me over correcting or chasing my body movement because of trying to use a higher magnification without stability for the shot.

Anyways I know I have experienced the parallax issues more than once but also feel it can have a lot to do with your tendancy to over correct with closer shots and higher magnification.
The more magnified the image is,,the more you seem to fight to be steady.
Thats what I find anyways.
I can usually shoot just as well or better when using lower magnification if I don't have a rock solid rest.

Maybe I'm missing something?
 

Mag 300

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    Re: bullet grouping question @ 100 and 300 yards??

    Bucky
    Your right on
    I was shooting next to a guy at 300 yds he was at 25 mag on the scope I had a 10 power leup.
    I shot 1/2 the group he did and we started talking . he reduced to 10 power and the group got a lot better.
    This appeared to be the problem.
    Bill