It seems that most people who test to confirm that their scope elevation adjustments track accurately recommend a live fire test: fire multiple groups on a “tall” target with calibrated expected points of impact at different elevation settings.

On the other hand at one time I saw a recommendation that the test be conducted in a similar manner, but by just ensuring that the reticle moved to different points on a target without firing groups.

Assuming that the rifle can be firmly fixed so it doesn’t move during the testing, I would assume that the no-firing test would eliminate the uncertainty of where the groups end up. I have fired successive groups that were nice and tight, but which varied somewhat in elevation. In addition, if conducted without firing, the tests could be completed more quickly and therefore more often than what would be practicable by shooting groups.

My question, therefore, is what advantages are there to conducting a scope tracking test with live fire? Or is it just something that shows up better in You Tube videos?

Thanks for all comments.

Shooting the test seems easier & faster.

I do box tests on all my scopes when I first take them out. Shoot, 10 up, shoot, 10 R, shoot, 10 down, shoot, 10 L, shoot.

Pretty easy to see it's tracking well from that - although I admit that with a quality scope like a NF I'm not breaking out the micrometers to check the percentages as long as it looks close and is tracking well.

A good friend made a base to mount his scope for tracking test. The VERY heavy base with a pic rail, leveling on all corners. Base is bolted to a very heavy/rigid table. He has a CNC router for his business. He CNC'd MIL markings on a piece of tall sheet of some sort. Target placed precisely at 100yds. Lot of of work to do this right. He's offered to let me put my scopes on his test rig, I've declined. He has data for several scopes, interesting most scopes are not dead nuts. That really doesn't matter if their off a few ball hairs.

I've had a handful of scopes fail, quit tracking, won't return to zero. Game I'm playing, LR steel matches, changing elevation for every shot is tough on scopes. Realistically most decent scope are good for about 5000-7500rds before having tracking problems when ramping the elevation turrets up and down.... If I suspect my scope is not tracking. Quick check. Shoot a few at 100yds, dial up and down a few times to 10 MILS or so, go back to zero shoot a few more. No need to shoot at distance for this. If scope passes that and I suspect tracking issue. I'll set up a level target at 100yds with 1 MIL marks to 10 MILS. Hold the same point, dial in 1 MIL increments.....

Scopes I've owned that quit tracking. USO, NightForce, Premier, Schmidt and Bender.

I mount scopes in my basement, with the rifle held firm by a Black & Decker bench/vise (yeah, pretty high tech & tactical A.F.), with an aiming wall 10 yards away. Once I obtain a rough bore sight zero, I dial elevation up 30 MOA, and see if the reticle moves about 3 inches upwards. This isn't exact, as most of scopes don't have parallax settings anywhere close to 10 yards. But it's a feel-good start for me.

Once zeroed outside at 100 yards, I do a quick 10 MOA box test by dialing the turrets -- right, up, & left -- and measure the results with my reticle. Assuming I have good dope for longer-distance shots, I dial up for those distances and confirm elevations with impacts on target.
This has been my process since I moved to Nightforce scopes.

*****
I performed 30 MOA tall target tests via shooting with my early Leupold Mark 4 scopes. They tracked OK, but not as well as my NF models. My Leupolds had some backlash, therefore I learned to dial one click past the intended elevation, then return to the correct elevation.

*****
Last year I had an AR15 that just wouldn't shoot consistently. I would get one bughole group at 100 yards, then the next one would be a shotgun pattern an inch or two away from POA. The carbine had a brand new barrel, with a new Vortex PST 2 2-10x scope. Zero wouldn't remain constant in both elevation or windage. I constructed a 60" cardboard target and tested tracking via live fire for 0 through 50 MOA, in 10 MOA increments.

The tall target test revealed a few issues:
- The new barrel wasn't installed correctly. Somehow the barrel moved a bit as the carbine heated up and cooled down. I discovered this when the gas block occasionally touched the hand guard. My gunsmith fixed the barrel installation and ground a little off the gas block to provide additional clearance to the rail. No more problems.

- The Vortex scope tracks well from zero to 50 MOA of elevation with live fire at 100 yards. For grins I dialed the scope all the way up to maximum elevation -- IIRC 60 MOA -- then back to zero. I found this process changed the zero by 1 or 2 MOA, pretty much every time I did it. When I dialed up to 50 MOA, then back down to zero, I no longer experienced a changing zero.

Lesson learned -- The Vortex PST is a decent scope, but its turret adjustments are not in the league of my NF models. On this carbine, 50 MOA of elevation would in theory get me to 1,000 yards, so there is no need to ever bump up against the top of the elevation capabilities. In reality, the effective limits of my 223 ammo means the scope will likely never be shot while using elevation of more than 25 MOA.

quote:

Originally posted by offgrid:
Game I'm playing, LR steel matches, changing elevation for every shot is tough on scopes. Realistically most decent scope are good for about 5000-7500rds before having tracking problems when ramping the elevation turrets up and down.

The more I shoot steel/tactical/precision matches, the more I see scopes crapping out. Elevation tracking seems to be the major problem. Offgrid and I have discussed this many times, especially as he moved to Tangent Theta scopes.

My NF scopes have not yet shown tracking issues, but a few of them have their share of rounds, with lots of elevations dialed. Some of the things I do now to reduce dialing:
- I no longer dial back to zero between stages-- unless I dialed into the second revolution on a long stage. I'm more cognizant of proper dialing now than I was a few years ago. I don't think I had any elevation dialing errors in this past year's matches. I do recall shooting at the wrong target a few times. In other words, I shot at target #3 with target #2's dope, because I lost target #2 in the transition. But my dope was good for target #2 -- DOH!

- I practice holding elevation changes via the reticle, rather than dialing. This has helped me in a few stages in certain matches. Especially when time limits are tight and the targets require relatively little adjustment in elevation. My reticles all have relatively simple vertical & horizontal lines -- they don't have the "Christmas Tree" holdover marks. Therefore, large changes in elevation are best done via turret dialing for me.

Time will tell when my NF scopes show their age.

Thanks, fritz; you addressed some of what I’m getting at.
For this question I’m not referring to catastrophic complete failure of the adjustment mechanism. It’s how well the sight’s mechanism is calibrated.

quote:

Originally posted by offgrid:
That really doesn't matter if their off a few ball hairs.

Well, that’s what drives my question. It obviously depends on the ranges we’re shooting at and the sizes of the targets, but in my reading some people believe that it can be very important.

As an example, if a scope adjusts the reticle position with 90 percent accuracy, what would that mean in absolute terms? If I dial up a mildot scope 10 mils at 100 yards, it should move the POI of a perfectly accurate bullet 36 inches. If the scope moves the POI up only 90% of that, however, the correct point of aim would be off by 3.6 inches at 100 yards, and by 36 inches at 1000 yards. Ninety percent would be a very gross error, but 95% accuracy would still cause a 1.8 inch aiming error at 100 yards and 18 inches at 1000.

This is something that the ballistician Bryan Litz discusses at some length, and the Applied Ballistics solver he developed even permits including scope’s tracking accuracy into the calculations.

I, however, have no experience to know how much error is likely to be inherent in the mechanisms of high tier scopesights. Long ago I checked a Leupold sight using the nonfiring method and had no concerns about the results, but I’m wondering if I’m missing something as compared with shooting groups.

To reiterate, even when my groups are nice and small, they don’t always end up in the same place relative to the point of aim. If one is 1/2 inch higher than the other due to my poor shooting technique, which do I decide is the correct indicator of how accurately the scopesight moved those points of impact? Yes, I could shoot more groups and try to find an average, but it seems to me that eliminating that uncertainty from the process would be a good idea. In my research thus far I often find advice to do X for the test, but no one ever seems to say, “Do X rather than Y because of Z.”
(And I’m not referring to the cost, convenience, or difficulty of either method, just which would give me more useful results.)

One useful bit of the Strelok Pro application:


If you find that your optic which is supposed to adjust .1 MRAD per click actually adjust .1053 MRAD per click. You can set that value in your optic information within the app.

So if you punch in your distances and wind to get a data card, it will give you the appropriate number of clicks.

quote:

Originally posted by IndianaBoy:
One useful bit of the Strelok Pro application:

Yes, Applied Ballistics has a similar feature.

quote:

Originally posted by sigfreund:

quote:

Originally posted by IndianaBoy:
One useful bit of the Strelok Pro application:

Yes, Applied Ballistics has a similar feature.

I played with it a bit in Strelok.

The app doesn't entirely solve the problems caused by a scope tracking error. Unless you dial everything, all the time, and can work in 'clicks'.

If you use a Christmas tree reticle and use a combination of 'clicks' and holdovers, having an error will screw you up eventually.

To me the tall target tests with a very solid fixture and a graduated target to measure adjustments is a very valid and viable test.


Live fire is just another variable which can introduce error.


Although I shoot box drills with all my optics when I first get them. I haven't build a fixture to test with.

quote:

Originally posted by IndianaBoy:
If you use a Christmas tree reticle and use a combination of 'clicks' and holdovers, having an error will screw you up eventually.

I can see that.

quote:

Originally posted by sigfreund:
To reiterate, even when my groups are nice and small, they don’t always end up in the same place relative to the point of aim. If one is 1/2 inch higher than the other due to my poor shooting technique, which do I decide is the correct indicator of how accurately the scopesight moved those points of impact?

That's a good question.

With a shooting discipline like heavy gun (or unlimited, or howitzer-class, or whatever they call it) bench rest, the shooter can be almost completely isolated from the rifle. And the results of their ludicrously small groups at 100 or 200 yards show the results. Not my game, but what is passed down from that discipline to other shooting events is incredibly valuable.

Which means that the least human-involved method to verify a scope's tracking accuracy probably involves a fixture similar to what offgrid describes above. Or strapping a rifle down to a solid bench, as I've seen in reviews of some ELR courses. If that works for you, go for it.

I'm probably stubborn, but I feel I should be part of the equation. At least some of the time. Shooting positions in steel/precision/tactical matches can vary from pretty solid to WTF-unstable. If I'm going to compete well in such matches, my shooting technique better be pretty good. Not bench rest good. And maybe not even F-class good. But good enough to hit what generally is 2-3 MOA steel, with occasional &$%*# 1 MOA steel, and a few 4 MOA gimme targets -- probably from unsupported positions.

Unfortunately, when I began playing this game, my shooting technique was pretty variable every day. Some days, it still is. But I've learned from those more experienced than I. Little things, which can be done without extra equipment.
- Like making certain the fundamentals are all solid. If the reticle's POA moves at all during the recoil cycle, the fundamentals aren't perfect.
- When targets are big and nebulous at distance -- as occurs with white-painted steel -- aim at the bolt on the plate. Or maybe the top or bottom edge of the plate, and adjust elevation a bit. Something I picked up locally from offgrid and Scott.
- Place a bold, contrasting, and horizontal line on a distant target when you're testing elevation or vertical variation. Don't worry too much about wind drift, but work on technique for elevation control. An offgrid thing.
- Being certain your ammo is up to par. Since I don't handload, I must search for ammo that works in my rifles. This can be challenging, but with some patience I get there. Not ludicrously small 1-hole groups, but generally close enough for my game.

Understand there are days that your shooting just won't be up to snuff. So be it. There will be other days to test the precision of your equipment.