Tall Target Test for Precision .22LR?

[GearMaker]

I haven't seen anything on this in my search of previous posts, so hopefully I'm not asking something that has been covered.

For the precision rimfire shooters (PRS Rimfire, NRL22, etc.) mounting your optics, do you perform a tall target test the same way as one would do for a centerfire rifle to ensure proper reticle orientation and scope tracking? I'm assuming you would, but what is the appropriate distance to place the target? I'm thinking 100 yards is too far since environmental factors could effect the .22LR POI as alignment/tracking issues with the scope. Are there any other changes to the testing that are necessary for the .22LR?

Thanks for your help!

 

[CNC-Dude]

With ammo velocities being out of your control, a tall target test would likely vary every time you did it making it difficult to establish a good scope dope. You could get close, but I doubt you can get as spot on as a centerfire shooter that can make precise reloaded ammo....

 

[GearMaker]

With ammo velocities being out of your control, a tall target test would likely vary every time you did it making it difficult to establish a good scope dope. You could get close, but I doubt you can get as spot on as a centerfire shooter that can make precise reloaded ammo....

Thanks, I probably wasn't clear in my post. I didn't mean for the purpose of obtaining dope, but verifying that a scope is mounted properly. My reference point was this video I saw on Youtube regarding using a tall target test as part of the optic installation process:

 

[Trung Si Ma]

Brian Litz at Applied Ballistics mentions tall target tests in several of his books.

I did it on my Vudoo with the Vortex Razor Gen III and was very happy with the results. Brian talks about doing the test at 100 yards but I did mine at 50 yards on a 48" piece of 1/4" gridded paper (got a 36" wide role from Amazon). I put a 1/2" dot on the row that was about an inch from the bottom and then moved the scope 5 mils left and shot a 5 round group before moving the scope 10 mils right and shot using the same center dot as an aiming point. When I was done with that group, I went 5 mils up, shot, them moved 5 mils left, shot, 5mils left shot again. Wash, rinse, repeat until I had used all 30 mils of elevation that I have in the Razor. When I shot my last group, I returned the scope to zero-zero and shot the 1/2" dot. I shot the dot last so that I would have the same clean aiming point throughout. I ended up with 21 beautiful little groups that tracked right up the vertical lines and across the horizontal lines.

My back up Vudoo is being rebarreled with a Shilen Ratchet and I will add a second Razoe to that and then do another tall target test on it. The only change that I will make is to high light the center lines around the dot to make it easier to alighn the cross hairs.

 

[jbell]

I do them on every one of my precision rimfire rifles when I install a new scope. I get a baseline for accuracy with that particular rifle and ammo combination so I know what my limits are. Then I test on calm days. I also test at 100 yards. I haven't yet not been able to get solid feedback with any of my precision rimfires at that distance.

In addition to the tall target test (shot on a plumb line) I also do a very intensive box test of my own design to confirm overall repeatability of my scopes.

Basically I do everything the same as with my centerfire rifles.

 

[USMC22]

With a tall target test you're attempting to identify the sight scale factor (i.e. yours scopes ability to track and identify any error).

The Snipers Hide Tall Target: https://www.boxtobenchprecision.com/store/snipers-hide-100-yard-scope-tracking-target

and a scope tracking tool such as: http://www.targetsusa.com/scope-tools.html or https://shortactioncustoms.com/product/final-scope-level/

is what you'll need. With that said... a 50 yard zero on my 22lr I'm ~1.8 mils for 100 yards. The variation in ammo is still going to be there even if you're scope it 100% dead on which is the variable you can't really iron out.

 

[GearMaker]

Thank you for the replies!

I have the Snipers Hide targets on the way and I'll go through the exercise of checking the scope's tracking as soon as I can get a day scheduled out at the rifle range. Hopefully I did a good enough job getting everything leveled when I installed the scope. I never quite trust how exact those Wheeler levels might or might not be.

 

[oldfatjonwick]

I haven't seen anything on this in my search of previous posts, so hopefully I'm not asking something that has been covered.

For the precision rimfire shooters (PRS Rimfire, NRL22, etc.) mounting your optics, do you perform a tall target test the same way as one would do for a centerfire rifle to ensure proper reticle orientation and scope tracking? I'm assuming you would, but what is the appropriate distance to place the target? I'm thinking 100 yards is too far since environmental factors could effect the .22LR POI as alignment/tracking issues with the scope. Are there any other changes to the testing that are necessary for the .22LR?

Thanks for your help!

the test should be done at your zero distance.

 

[GearMaker]

the test should be done at your zero distance.

Thank you! That makes sense.