Confirm if I was correct, please.

[DartonJager]

Had friend ask me at what ranges do ES & SD begin to matter in shooting.
I paused for thought for a moment and replied;
I'm not certain but seeing as bullet BC doesn't come in to play and have a significant impact in popular hunting high velocity rifle calibers until after 400 yards or more I felt SD & ES were of similar importance and so they also don't begin to matter until after 400 yards.

Was I correct or not.

 

[jessej]

Velocity spread alone will affect your groups vertically. Also keep in mind that if you have bigger ES's, you probably don't have a perfectly tuned load, which means vertical and horizontal changes in POI. I have rifles that shoot really good out to 500 that have horrible ES and SD. They tend to fall completely apart on my 800 yard tall target. But they are skinny barrel hot rods that I don't expect much out of. The rifles u have that shoot LESS than half moa at 1k, all have very minimal ES. But what do I know, I'm just a dumb ole redneck that deals with 90+% humidity 10 months out of the year……..

Careful. You're circling one of the rabbit holes.

 

[.gacton]

^^^
What jessej said. And watch that rabbit hole! Lol

 

[jessej]

^^^
What jessej said. And watch that rabbit hole! Lol

A brief moment of clarity. Don't always count on it

 

[Mikecr]

I don't completely agree.
BC and SD/ES are different things.

Whether ES/SD matter, and how much, depends on the tune.
I shoot groundhogs with headshots, often all I have,, a bit beyond 500yds with a low BC 22cal BR bullet and relatively high cold bore SD (~15fps).
My tune just works good with it.
There is no ballistic software that can predict this, so it has to be shot to know.

 

[dhbikerczar]

So I had a load that typically has a5 shot group with ES of 5 to 3 fps but I could never get it to group. I tried another load that was well under 1/2 MOA, but ES on 5 shot groups was closer to 15 fps. Can't tell the velocity spread under 500 yards, (214 gr HH going 3200 fps)

 

[Greyfox]

For a given cartridge and target size it would be easy enough to determine your effective range using a ballistic calculator. By loading the two extreme velocity(ES) values you can compare the difference in the two drop values to the size of your target. ES/SD matters at the range in which the spread exceeds the desired target size(weapon employment zone). The same methodology can be applied to determine wind dope certainty.

 

[Mikecr]

You should believe what a target tells you

Neither ballistic calculator, nor chronograph, will tell you where a barrel puts bullets.
Also, ladder testing shows barrel summations and compensations, in both vertical AND horizontal.

 

[L.Sherm]

You should believe what a target tells you

Neither ballistic calculator, nor chronograph, will not tell you where a barrel puts bullets.
Also, ladder testing shows barrel summations and compensations, in both vertical AND horizontal.

1000% correct.
Nothing else matters except what the target says.

 

[fnlights]

1000% correct.
Nothing else matters except what the target says.

Agreed. The only real time I even look at my velocity is after my load has been developed to get a rough baseline for the ballistics calculator.

I think it also depends on the chrono that you are using. If you are trying to find single digit ES with a cheap Caldwell chrono, odds are you will shoot out the barrel and still not find your load. I have seen my cheaper Caldwell vary significantly - so if you are going to stress finding ES and SD, make sure you are using a reliable chrono.

 

[Greyfox]

You should believe what a target tells you

Neither ballistic calculator, nor chronograph, will not tell you where a barrel puts bullets.
Also, ladder testing shows barrel summations and compensations, in both vertical AND horizontal.

I "tend" to agree with this, but unfortunately with the broad spectrum of conditions, and distances encountered when LRH, a MUCH higher level of control, certainty and consistency can be achieved when analytics and actual targeting excercises(ladders, etc.) are symmetrical…"It's all relevant"….IMO

 

[bassassassin104]

IMHO, as long as your tune is decent you are correct. Mikecr said it pretty well and I agree with him. A ladder test will show you how much velocity variation your load can take without seeing extreme variation in point of impact. As for the direct affect of velocity on bullet drop, you can play with a ballistics calculator a bit and get a good idea of how much variation to expect with a specific ES. For example my .260 from 2920-2950 fps shooting a Bullet with .625 BC will have a theoretical vertical variation of .6" at 400 yards. That calculation is assuming everything else is exactly the same every time but it gives you a decent general idea.

 

[Beluebow]

Having looked at thousands upon thousands of shots through electronic targets at LR...I can tell you with absolute certainty that the rifles with the lowest SD's tend to be the smallest shooters.

I think it probably comes into play at 100yrds but being able to see it is another story. The dispersion becomes more apparent at longer yardages and over longer strings of fire (repeatability).

Examples

Low SD over a 27 shot string

Higher SD over a 23 shot string....notice the vertical dispersion starting to come into effect.

 

[Mikecr]

Considering both of those targets, and long range HUNTING, you could focus and stop on shots #1 & #2.
For those, notice better accuracy with the higher SD shooting. That's the load I might lean toward.

As far as 20 shot patterns, it means nothing for hunting.