Home Forums Hunting & Shooting Long Range Hunting Tall target test

The point of aim remains the same. The adjustments alter the point of impact only.

The accepted norm for most load testing is groups at 100 yards, it only makes sense to test a scope at 100 yards in this way. A known rifle, with a known load, will yield recognizable results regarding the center of a group size at the point of impact.

Wind ~ first of all pick a day with minimal wind conditions. Second of all, that's part of the point of testing a load or scope at 100 yards. Far less chance of wind influence than at say, i dunno, 1000 yards?

Bench technique ~ most folks who would bother with a test like this already possess more than adequate bench technique. Personally, I don't like a bench. Bipods and rear bag. I test the same way I would shoot.

Mirage ~ wonderful wind indicator if your lucky enough to see it when your shooting.

Shooter fatigue ~ eat your Wheaties, get some sleep.

3 shot groups ~ two less than 5. Shoot whatever floats your boat. We are testing a scope, not a load.

Canting ~ time to install an anti-cant device if canting is an issue.

Inherent accuracy of the rifle ~ dunno about you but I'm not putting a scope worthy of long range on a rifle that isn't.

Point of aim ~ in this test your point of aim always remains the same. Optimally at the bottom center of the target. You are testing the erector of the scope by comparing the actual point of impacts with the amount of MOA or MILS dialed into the scope. IOW, does inputting 5 MILS in the scope actually move the point of impact UP 5 MILS above your POA? Does 10 MILS dialed move the impact UP 10 MILS above your POA? When you dial back to your zero stop do the impacts actually return back to your actual "ZERO"? These are important things a long range shooter needs to know about his rig. Thus, the test.

I do center fire at 100, rimfire at 50.

In both cases, minimizes the effect of wind on the outcome

Yeah, that's where I'm at as well. No need to shoot a centerfire rifle ever at 50 yards, unless a nice bull is standing broadside in front of you.

Excellent thread John. I always appreciate your input. I know you are a shooting sob!!! That Tract scope looks like it's doing a great job. One of my buddies back in Washington uses Tract scopes on some of his precision rifles. The glass is pretty nice.

Great post buddy. I appreciate that. Hopefully barm understands all that. One thing I'd like to mention is, even though I am calling this a "tall target" test, it is really more than that, as you have explained. I like to use this test to also confirm the load and rifle, and how it shoots as the barrel heats up: Or if it shifts POI as it heats up.

Also, as long as you make note of what the wind is doing and it pushes your group over, you know that is what caused it. You'll notice on some of my targets, that I made note of that. With the "long range" competitions I shoot, you are also dealing with barrel heat, because you can not wait long between shots because they are a timed event. Not like some of my other shoots, where you do slow fire: 1 shot per minute.

In this test, I am firing roughly 18 rounds without letting the barrel cool. Unless I'm shooting 2 rifles. Then the barrels have just a little time to cool. I'll shoot the groups pretty quickly, especially if its windy.

Last week I was thinking about this thread and figured I should add this information in, so guys know exactly what my intent is with this test. I think you explained it well though. Thanks

Put your rifle in a vise and place the cross hairs on your target. Start moving your elevation turret, what happens? Don't touch the rifle or try to move it. Does your point of aim move?

Place your rifle in the same vise and place the cross hairs on your target. Shoot a group on the paper. Now place a piece of cardstock that has been folded between your barrel and the forend of the stock. Slide it back with enough force that it wedges in the gap with force and won't go back to the receiver. Shoot another group. Does the group change it's location on your target? Remember your scope is still on the target and you have not made any adjustments to the elevation knob. Did your scope fail the test?

Next place your rifle in the same vise and get the bore perfectly level to the target. Now shoot a group. Where did it hit? I am sure it is low, correct?

These examples should illustrate that point of aim and point of impact are not the same. We use scopes and sights on a rifle to move our point of impact. That doesn't mean point of impact will accurately measure changes to the point of aim. To measure the accuracy of a scopes adjustments you need a test which measures changes in point of aim.

I am not trying to crap on the test. I am really glad to OP went to the trouble of doing it and sharing his results with us. It is valuable information that he provided. I am trying to get all of us to put our heads together and determine a way to get the answers we all want.

That's a LOT of words to say you don't understand what's going on here.

There are also "scope checker" fixtures available where two scopes are mounted parallel to each other to verify tracking off the rifle. One scope remains locked on the starting point where the other is tracked/checked on a grid. I have never seen one used, but some of our local F Class competitors have them.

I ve seen it done with a scope checker you have to have a frozen fixed scope on the checker to test your scope against. Its the only way to test a scope properly.
Think about it, how may thou does it take to build in 20 moa into scope rings.
I think .001 = 1 moa

Feeling generous today, and I have a few minutes. I'll address that paragraph. The rest of it you're just inventing unrealistic scenario.

We start with a zeroed rifle. That would be a scope that is adjusted to cause the trajectory of the bullet to intersect your line of sight at a prescibed distance. Typically 100 yards.

An optic with elevation turrets allows you to internally adjust your line of sight, to cause a change in the attitude of the barrel, to cause a taller trajectory, so that the bullet will intersect your line of sight at distances beyond your initial zero. Everyone knows the same can be done with reticle hold overs, but the turret allows the line of sight to remain centered in the scope.

If your data calls for 11.2 MILS to intersect your line of sight at 1000 yards with a rifle that is zeroed at 100 yards, dialing 11.2 MILS will cause a bullet to pass over your line of sight 11.2 MILS high at 100 yards, or roughly 40.3 inches above line of sight. The easiest way to SEE that is to have the bullet strike a tall target at 100 yards.

The entire point of THIS test is to see if the scope actually produces 11.2 MILS of adjustment, meaning you're causing the exact amount of elevated attitude of the barrel for the bullet to strike the point of aim at 1000 yards.

You can do the same exact test AT 1000 yards if that suits you, seeing if your bullet strikes low or high from POA, but you're dealing with wind as well and likely skewing your results. Wind doesn't just affect lateral movement of the bullet, it can affect elevation as well. A scope passing this test at 100 yards leaves you with concentrating on atmospheric conditions instead of factoring in scope adjustment error as well.

Great post. Where was the range that you shot? MTG

barm, the main intent of this test is to test the scopes for accuracy of the elevation turret adjustment. This test is best done with the recoil from the rifle vs. a static test in a vise. There are some scopes that will pass a static test, but fail a test that is done when recoil is added. Formid did one a while back, on Rokslide, with the same type of scope my buddy was having issues with. This is the reason I decided to check my scopes. As it turns out, I have 3 Nightforce SHV rifle scopes that have about a 3% tracking error. The other 2 Nightforce rifle scopes I have are pretty much spot on. I have also checked these scopes multiple times, and they show the same error. That confirms the errors are consistent, and one of the reasons they do not match up exactly with the ballistic calculators I've used.

I also want to add that this test can be done with any scope, as long as it has a numbered turret. Even a cheap Burris...


...like what I use on my AR's can be tested and checked^^^^.

Moral of the story, if you twist your dials at all and you have noticed some kind of anomaly or error on targets downrange, then a test like this may tell you what you need to know. When I say downrange, I mean past 400 yards.

It's easy enough to do at 100 yards. Hang your target plumb, shoot at one point (the bottom dot on my targets for example), and adjust your turret and see how it matches up with your measured increments. When I do this test, I am also testing my natural point of aim, to see If I am holding the rifle so the reticle is perfectly plumb. If you find that you cant your rifle when you shoot, that could throw the POI off to one side or the other. So like I said in another post, it's not just about the tracking of the scope. When shooting this test, you are testing many factors that may cause a miss downrange. However, most importantly is if your scope is dialing as it should.

Thanks buddy. This is in Nevada.

The things I’m confirming when I do the test are alignment with the bore, and that it tracks accurately and returns to zero.

If it tracks accurately and returns to zero, that beats a lot of scopes.

If it doesn’t track accurately, alignment past 300 yards or so doesn’t matter, and that’s where I usually start dialing.

I have a friend that shoots PRS who uses a night force ATACR with the tremor3 reticle. Once alignment is confirmed, he shoots dope using the reticle without dialing.

That is a good suggestion. I use my MOAR reticle as well sometimes. It's real quick for shots out to 600 yards and even further. Many ways to skin that cat. Also, I was thinking about this in my post yesterday, but if you have a reticle that is very accurate, like the MOAR in the Nighforce scopes I use, you can check your target with it to confirm you have measured out your points correctly. I did this each time, with every scope, and the reticles were spot on. But like I said, there was tracking error in 3 out of the 5 scopes tested. Not including my buddies Vortex Razor HD. That thing was whacked out in the horizontal adjustment and actually moved (shifted POI horizontally) during recoil. That was pretty frustrating.

He does that like just about every other PRS shooter does. There's no time in a stage to fool with turrets, none. My match partner and I would dial for one target, usually the closest, and hold for the rest. Occasionally some stage rules we would shoot would not let you dial anything, you had to use holds. Came home many a time with dope scribbled on my hands. I never dialed wind ever, always held for wind.

That is why I own a herd of NF's.

Don't ever think a NF is immune to problems, I saw one go completely to [bleep] on the line at Deep Creek in Missoula, MT. I saw another not do so well with a scope checker.
There was alot of BR shooters had problems few years ago with the 15-45 NF thats why you saw alot of them for sale.
They are a good scope I have 2 - 4- 32 NX8 on my LR hunting rifles

Thanks for the info sherm. I know a few guys that run these same cheaper SHV 5-20x56 rifle scopes and dial them a lot in our long range varmint silhouette matches here. Haven't seen one fail yet, but I am always keeping an eye on stuff like that.


I've wondered why the various NF target scopes were less expensive. I'll stick with the SHV and ATACR then..