The Tall Target Test (video) Comments?

[LDHunter]

This was pointed out to me/us in a Gunbroker newsletter and it makes a lot of sense to me. I hope y'all forgive me if this has been discussed before.

https://www.youtube.com/watch?v=12Wf0Cuwwi8&feature=youtu.be

I'd like to hear from some of the long range shooters here if this guy is right on the money or not.

The guy that made the video is Bryan Litz, ballistician, author and president of Applied Ballistics, and he says, "Before you go to long range you need to to some short-range work." Watch his walk-through of the "Tall Target Test" and learn how to get your sights properly aligned, zeroed and tracking vertically.

I'll be interested to see how my Mark 4 scopes stack up against my NightForce scopes.

Comments?

$bob$

 

[Bravo 4]

Couple of comments:

I do this as well. However I test the adjustments of the scope without firing first, you can find out if the turrets/reticle track true without firing a round. Takes out a lot of inaccuracies from the gun and shooter. Then put some rounds on target to make sure all is well, kind of a trust but verify ordeal.
I also would have used the tape first and moved the rifle back accordingly, my bench and target are exactly 100 yards apart. That just makes sense to me but I understand why he showed how to make a correction.

This video showed what I have observed with almost every Leupold I've owned, check your adjustments!

 

[LittleCornball]

I have yet to apply this technique to my optics but the process appears sound lest I am missing something. Bravo I am curious as to your process for testing without firing are you able to explain it briefly for me. Thank you.

 

[Rick Richard]

Make reference points such as 1 inch marks (horizontal lines) across the vertical line. Move scope X amount of clicks and verify where it ends up on the vertical line. 100 yards of course.

 

[LittleCornball]

So obvious where is my brain. Thanks.

 

[Reloder28]

I am still on the long range learning curve. When he cranks his scope up, how many MOA is he going? I thought he said 30 MOA. If it only takes 9+/- moa to reach 600 yards how far is 30?

 

[Rick Richard]

Depends on caliber, BC, Muzzle Velocity and a couple of others. All of these inputs are needed to determine MOA = yards for a specific application.

 

[sambo3006]

He is cranking it up 30 moa to make it easier to see if the scope is canted at all. The farther up you adjust from zero when you shoot the tall target test, the farther off the impact will be if the scope is canted. If he only went 9 moa up, the impact shift from a very slightly canted scope would be small enough as to make one question whether it was just shooter error or part of the actual grouping capabilities of the rifle rather than scope cant. Hope that makes sense. I does to me but maybe not to anyone else.

 

[Bravo 4]

Most guys don't check their scope adjustments. It can play into the whole "junk in-junk out" response to truing your ballistic apps. If you don't know to input the correction to your turret adjustments then you will end up tweaking your BC or velocity numbers to compensate for the correction and not even realize where the correction needed to be applied in the first place.
Is it usually enough to throw you off if you make it up elsewhere? No, especially if you aren't going to be shooting some crazy freaking distances and expecting your app to get you a true solution for first round hits. I have checked some rather expensive scopes and found their adjustments to be off by as much as 10%! That is huge and this optics company when contacted said "What's the problem with that?"
You can also find out if your adjustments stay true through the whole range of adjustments. I check from top to bottom, I've heard that the adjustments can go astray towards their outer most limits. I haven't found one that does that, but I will check because I have had a setup that only had 4 moa left with a 100 yard zero. It was at the outer limit of its adjustment range and I needed almost all the rest to shoot past a mile if so wanted.
You can also check for any reticle cant, which some scope manufacturers seem to have crappy acceptable tolerances for. One of them being the same company stated above.

Now then, with all of that said I think that as long as everything is repeatable then it is functional. You can compensate for pretty much anything. It's a system and if you change something (like your rangefinder, how many guys check their rangefinders?) then you need to verify again.
The process is time consuming because I will do it many-many times to verify any findings.

As stated above, I will make a target like Mr. Litz but taller and with .25 moa or .1 mil marks and strap the scoped rifle (or maybe just the scope) to a gun cradle and bench so that it will not move when I turn the turrets and go from there. The set up process is the time consuming part, getting everything lined up and strapped down just right. Sometimes I get my youngin to aid me with this.

 

[royinidaho]

from where should the distance from shot spot to target be measured. From muzzle or from somewhere along the barrel?

It appears to me that he measured the distance from well behind the muzzle?

Also, if the Tall Target line is precisely perp to the earth and the scope level says shows level and the vertical reticle is not parallel to the Tall Target line..... and ..... the scope level is adjusted to make things plume.....will that not introduce cant? Don't know, just ask'n...

 

[bruce_ventura]

For the purpose of measuring turret click values, the range should be measured from the scope objective to the target.

 

[Barrelnut]

Also, if the Tall Target line is precisely perp to the earth and the scope level says shows level and the vertical reticle is not parallel to the Tall Target line..... and ..... the scope level is adjusted to make things plume.....will that not introduce cant? Don't know, just ask'n...

I always make my reticle perpendicular to the earth by aligning it with a plum-bob and then I set the bubble level to agree with that. I pretty much do it just for this reason.

 

[Bravo 4]

As do I Barrelnut, for the most part as long as the reticle isn't canted.

This can make a small difference if you turn turrets or if you use a mil/moa/BDC reticle.
If turning turrets and the reticle is canted inside the scope, then do you make sure to go off where the turrets are taking the reticle? My last two MK4's had a noticeably canted reticle and Leupold wouldn't fix them. Can't go off the plumb bob with that happening.

 

[Bravo 4]

Here ya go: