100 Yards from Muzzle or the Scope?

[BigDave]

Please dont laugh. Stupid question here.


Say I had a 40" barrel. I dont..mine is 24". But lets say mine is 40". Do I laser 100 yards from my muzzle?..or scope objective. Muzzle, right?

Now, lets say I want to do a NON shooting tracking test of my new scope. I have a large grid set up with three horizonal lines 18" apart and a stick on yellow circle in the center of each line. Here, just look at this:

http://heelsandhandguns.com/2013/11/test-tracking-rifle-scope/

Instructions say to actually use a 100 yard tape or a 100 foot tape three times from the scope objective lens to the target. Right? So I do the test and all checks out. Now when I actually go to shoot I need to move the target back X number of feet so it is now 100 yards measured from the MUZZLE.

The scope is going to track a bit different now since the target is 303 feet past the target. This has got to be insignificant right? Or not? Since my barrel is 24" the difference between muzzle and objective is about 1.5 feet. Does that distance ever become a factor? Probably not since I have not even seen this idea addressed. Just wondering.

They call it PRECISION Long Range Rifle. Guys measure hand loads (bullet seating, neck trimming etc) to .001". You know what I mean....
We are talking feet of target vs muzzle vs scope objective discrepancy that we just pretend doesnt exist?

So, why dont I just use my Nikon laser range finder to measure out the all the test distances? The cost and hassle of a tape hardly seems worth it. or are the distances really critical for what I want to do...down to factions of a foot?

Off topic but related a bit:
My scope has a measly 7 mils UP travel so I really dont need that giant piece of plywood. Seven mils x 3.6= 25.2"
So, say a 30" x 30" cardboard with a grid in portable Birchwood Casey holder.

In any event this method of tracking testing seems to work quite well. They found one Leupold of theirs that was a good bit off and Leupold agreed and repaired it.

[Jamie]

My honest answer is to shoot more and read the interwebs less. Does the three feet matter? At 100, no but put a target up and shoot it to see if there is a difference. By the time it truly makes a difference most people can't hold inside the error any way.

[shooterfpga]

Sounds like a hybrid box test with a tall target test. Split the difference between objective and muzzle.

[JackinSD]

Holy Crap! Reading way too much into things.

[wbm]

My honest answer is to shoot more and read the internet webs less. Does the three feet matter? At 100, no but put a target up and shoot it to see if there is a difference. By the time it truly makes a difference most people can't hold inside the error any way.

+1.

[barrel-nut]

By the time it truly makes a difference most people can't hold inside the error any way.

+2. Nor can most rifles.

[Robinhood]

My honest answer is to shoot more and read the interwebs less. Does the three feet matter? At 100, no but put a target up and shoot it to see if there is a difference. By the time it truly makes a difference most people can't hold inside the error any way.

This


They call it PRECISION Long Range Rifle. Guys measure hand loads (bullet seating, neck trimming etc) to .001". You know what I mean....
We are talking feet of target vs muzzle vs scope objective discrepancy that we just pretend doesnt exist?

Maybe I'm wrong but for me Precision and 100 yds are not in the same Paragraph. Anybody can get 1/2 MOA or less at 100. Hold that at 600 plus.

[D.ID]

My honest answer is to shoot more and read the interwebs less. Does the three feet matter? At 100, no but put a target up and shoot it to see if there is a difference. By the time it truly makes a difference most people can't hold inside the error any way.


Holy Crap! Reading way too much into things.


This



Maybe I'm wrong but for me Precision and 100 yds are not in the same Paragraph. Anybody can get 1/2 MOA or less at 100. Hold that at 600 plus.

+ Another.
Do not waist your life worrying about the irrelevant theory within the imaginary margin. GET OUT AND SHOOT! You'll get allot more out of it.

[yobuck]

Well if it's (precision) long range how come all those that ever set records never repeated it?

[shooterfpga]

You guys missed the ballpark. It sounds like hes performing a tall target test. Its to measure how accurate his scope turret tracks to what its advertised as holding. Once he gets this measurement he will adjust his dope chart with the correction factor.

[Jamie]

This has got to be insignificant right? Or not? Since my barrel is 24" the difference between muzzle and objective is about 1.5 feet. Does that distance ever become a factor? Probably not since I have not even seen this idea addressed. Just wondering.



You guys missed the ballpark. .

I can't speak for the rest, but am pretty sure I understood what he was asking. If he does a tracking test with the target 100 yards from his scope and then shoot his groups at 100 from the muzzle, there could/should be a variance of accuracy for the tracking of the scope to actual bullet impact. Barrel is 24, scope probably overlaps from breech 6" +/-. leaving at target variance of about 18" (1.5 ft).

Original answer still applies, go shoot it. On paper it will be about .6" at 500 yards and 4" at 1K yards with my 6x47 Lapua, which means for the vast majority of people it will never be a factor, but you have to go shoot it and see.


Dave-
I understand the larger picture, you want to learn everything possible to be as good as possible for this endeavor. Good on you! But......the absolute best way to learn it is to spend time behind the trigger. By the time you get 2K rounds through that rifle at different distances, you will know what happens at those distances, you may not understand why it is happening but you will at least know what is happening. Basically don't worry so much about the little things until they start showing up in your shooting. Until then they are what ifs and theories.

[Newsshooter]

Yep, tracking test, good to do to make sure the scope is working correctly. Computer dope vs real world dope, the two don't always match. While my computer dope gets me in the ballpark, real world shooting gives me the actual dope. Might be only a few clicks but it does make a difference.

[yobuck]

Yep, tracking test, good to do to make sure the scope is working correctly. Computer dope vs real world dope, the two don't always match. While my computer dope gets me in the ballpark, real world shooting gives me the actual dope. Might be only a few clicks but it does make a difference.

And you know what else? real world might vary from today till tomorrow. Precision my butt, it is what it is the day your doing it.

[Newsshooter]

And you know what else? real world might vary from today till tomorrow. Precision my butt, it is what it is the day your doing it.

Yep, temp and baro pressure can change it but isn't going to change that much and it can be calculated. How often do you shoot from 300 to 1K or farther? F Class, High Power, Tactical, Bench Rest etc? The guys that shoot the Precision Rifle Series are pretty **** good at shooting, Period. Matches include shooting in a wide variety of positions, moving positions between shots, shooting off barricades, and different types of props, multiple targets at different distances and generally under time constraints. 90 seconds would be a long shoot time for a stage that might include two shots on five different targets none being bigger than 3MOA at different distances from say 100-600 yards. Might not be benchrest groups but it's **** difficult to do well.

[yobuck]

Yep, temp and baro pressure can change it but isn't going to change that much and it can be calculated. How often do you shoot from 300 to 1K or farther? F Class, High Power, Tactical, Bench Rest etc? The guys that shoot the Precision Rifle Series are pretty **** good at shooting, Period. Matches include shooting in a wide variety of positions, moving positions between shots, shooting off barricades, and different types of props, multiple targets at different distances and generally under time constraints. 90 seconds would be a long shoot time for a stage that might include two shots on five different targets none being bigger than 3MOA at different distances from say 100-600 yards. Might not be benchrest groups but it's **** difficult to do well.

There isnt any argument from me on any of that. But try that same approach while sitting on a mountainside looking across a wide
deep valley with a very large stream running below. Conditions could be changing while your getting all your ducks in a row.
Yes it might not be much, but enough for whats known as a miss. Especially with distances starting at 8 or 9 hundred and going to a mile or more.

[wbm]

Conditions could be changing while your getting all your ducks in a row.

Yobuck say it ain't so! You shooting Daffy Duck with a rifle?:suspicion:

[yobuck]

Yobuck say it ain't so! You shooting Daffy Duck with a rifle?:suspicion:

Well to tell the truth ive not been able to hit one of those dammed things.
Either the currents too swift or im not swift enough.
But seriously large streams do cause some pretty impressive thermals.
In the early fall especially hang gliders jump off some of those ridges like at Hyner view vista for example.
They can seemingly glide around as long as they wish up and down those valleys.
Shooting thru that stuff can be challenging.
You can Google some of the places, Bush dam vista is another chip shot lol.
Shooting from there starts at 1600 to you aint got enough gun.

[Newsshooter]

There isnt any argument from me on any of that. But try that same approach while sitting on a mountainside looking across a wide
deep valley with a very large stream running below. Conditions could be changing while your getting all your ducks in a row.
Yes it might not be much, but enough for whats known as a miss. Especially with distances starting at 8 or 9 hundred and going to a mile or more.

I suppose that is true, but I'd guess the guy shooting 100 rounds a month or more might have a decent chance. I've certainly seen wind changes catch shooters out at long distance. I only shoot targets a long ways away for fun. For shooting at game I use a Bow. :)

[barrel-nut]

I googled Hyner View. That's some pretty country up there. Looks like the country in the movie "The Deer Hunter" if I remember correctly.

[Russmerle]

I check scope tracking by:
- zero rifle,
- aim for center, shoot center
- adjust 16 click up 16 click right, aim for center, shoot
- adjust 32 click down, aim for center, shoot
- adjust 32 click left, aim for center, shoot
- adjust 32 click up, aim for center, shoot
- adjust 16 click down 16 click right, aim center, shoot center

Connecting the dots, this will print an 8" x 8" box with two rounds in the center. You can tell if 1. Your scope is level 2. The turrets are actually 1/4 MOA adjustments. If the shape is a diamond, your scope is slightly crooked. If your shape is square, your scope is level. If the pattern isn't 8"x8" and the distances are off, your adjustments are not 1/4 MOA. Also, please take into consideration the human aspect in this test if shot placement is off.

If you're splitting hairs, for the purpose of this scope calibration, the 100 yards should be measured from the lens. Will it matter? Not so much because at 100 yards your difference in 18" will equal .052"... This should be unmeasurable and like some said here, we can't shoot that good nor can our rifles...

If you really want to test your dope; you should try the Hornady ballistics calculator and print the chart after you enter proper info. Do the generic version because it doesn't take environment into consideration. Zero the rifle at 100 yards and then move to 300... The hornady chart will tell you the bullet drop and how to compensate. Mine is approximately 14" at 300 yards. Make adjustment to your dope and then shoot. It's pretty amazing when your rounds impact where they're supposed to. I used my Hornady ballistic chart when I shot at my buddy's farm and it was pretty fun. Mapping your own dope is the way to go if you have the freedom to shoot at different distances. Good luck shooting and I'm sorry this was so long.