scope trackingl Tall Target Test

[shaunharkin]

Hi there would some one help me to find the CONSTANT number to work out the tall target test
please My scope is in meter and clicks is mrad 0.1 cm Thank you my scope is 5/25/56 smith and bender

 

[Chuckhunter]

Re: scope trakingl Tall Target Test

http://accurateshooter.net/Blog/talltest02op.png

 

[brian427cobra]

MOA's are not inches, and MRAD's are not metric

 

[Jay Christopherson]

You might want to ask Bryan Litz directly, maybe via the Ballistics board. I am not sure how he derived the constants.

 

[MDM]

Get yourself and 1ft section of I-beam, about 70-80 lbs. Drill and tap it for a scope base so you can mount your scope up solid. Make a board with marks to match your click adjustments. Run your scope up and down to see how it matches up. It's the only way to tell exactly how you your scope is tracking and removes all shooter/load induced error. Something like this...
https://www.youtube.com/watch?v=f2VVOfnirFc

 

[Jarhead6870]

Hi there would some one help me to find the CONSTANT number to work out the tall target test
please My scope is in meter and clicks is mrad 0.1 cm Thank you my scope is 5/25/56 smith and bender

Couple of ways of checking scope tracking as mentioned above but for the simple version, I use a 40" - 42" piece of of cardboard that's about 4" in width. I then draw a line with a marker in the center of the cardboard lengthwise. I make a reference dot on the line about 2" from the bottom of the cardboard and then measure from the center of the dot, up 18" and 36" and make hashmarks at each location. The reason you use the 18" and 36" locations is that .1 of a MIL is .36" and 1 MIL equals 3.6". So, 5 MIL is equal to 18" and 10 MIL equals 36". I even go a bit farther and use a pair of dividers to divide the 18" into 5 equal parts thus giving me the locations/measurements for 1 MIL increment all the way to 36".

To test, mount the target at 100 yards and hang the tall target vertically with a level. It's imperiative that it's vertical. Then shoot a 3 shot group at the reference dot making sure the scope is held vertically. Dial your scope up 5 MIL and shoot a 3 shot group while still aiming at the reference dot. Then dial up another 5 MIL, i.e. to 10 MIL, and shoot another 3 shot group, again while aiming at the reference dot. To conclude, dial your scope back to zero and shoot another 3 shot group at your reference dot. Again, make sure that all shots are made with the scope vertical.

If your scope traks properly, you should see your groups all on your vertical line at their respective, dialed MIL locations and the the return of your scope zeroed group consistent with your starting group at your reference dot.

Hope this helps...

 

[/VH]

"To test, mount the target at 100 yards"

Wouldn't he need to place the target at 100 meters?

 

[hogpatrol]

MOA's are not inches, and MRAD's are not metric

Actually, MILRAD is.

"Though many people have adapted to the MOA standard, another system, the MilRad lives in the metric world. A MilRad is equal to one 1000th of the target range. This is laid out in a circle around the shooters position, with the target range as the radius. Which means, 2 x π x 1000. Therefore 1 MOA = 0.2908 MilRad. Adjusting one Milrad up at 100 meters will result in an offset of 100 mm. The markings on a reticle that mark MilRads are called MilDots. Such a reticle is called a MilDot Reticle."

http://precisionshooter.co.nz/shooting-units-moa-minute-of-angle-milrad/

As anyone who has worked with the metric system knows, the tall target test for a milrad scope is a lot simpler than our archaic inch system. Instead of converting and using inches I would hang a vertical metric scale (one with a hole in one end so it hangs plumb) at 100 meters and start cranking the turrets. One click will give you 10mm. Easy peezy. ;D

If your scope's in 1/4 " clicks, use a regular English system ruler.

 

[Jarhead6870]

"To test, mount the target at 100 yards"

Wouldn't he need to place the target at 100 meters?

I always thought this to be the case but questioned it when reading so many posts by other shooters who used yards that I called Vortex, since I use their Razor Gen II, and asked them which to use. Their reply was to use yards...I don't know if this distance holds for scopes from other manufactures. I do know that whichever distance you use as recommended by the manufacture, the distance should be measured from the turrets to the target.

 

[/VH]

In light of hogpatrol's explanation, I think 100yds would be correct for your method, Jarhead.

 

[hogpatrol]

"To test, mount the target at 100 yards"

Wouldn't he need to place the target at 100 meters?

I always thought this to be the case but questioned it when reading so many posts by other shooters who used yards that I called Vortex, since I use their Razor Gen II, and asked them which to use. Their reply was to use yards...I don't know if this distance holds for scopes from other manufactures. I do know that whichever distance you use as recommended by the manufacture, the distance should be measured from the turrets to the target.

Jarhead, since we use mostly yards here, I can understand what Vortex told you but since the OP is in Ireland, probably best for him to stick to the metric system. The whole milrad converting to yards and the english system for him is probably just as confusing as the metric system is to most of the U.S. If I were him I'd stay with the way milrad is supposed to be used, i.e. the metric system.
/VH you are correct, 100 meters.

 

[/VH]

hogpatrol,
Wouldn't 100 yds be the correct distance for Jarhead's 18" and 36" spacing (based on 3.6"/mil)?

 

[hogpatrol]

hogpatrol,
Wouldn't 100 yds be the correct distance for Jarhead's 18" and 36" spacing (based on 3.6"/mil)?

Yes it would. I would qualify that distance as being at one specific power for SFP scopes.

The answer to the OPs question about constant is .03936. (as posted in chuckhunters link)

 

[/VH]

hogpatrol,
Thanks for your explanation above, particularly, "A MilRad is equal to one 1000th of the target range." I may have read this before but this time it seemed to click for me in a way that I think I can remember without the convolution of a "measurement system" and conversions needing to be involved. I think I may have space in my limited brain capacity to remember this simplified version.

 

[fredo]

Hi there would some one help me to find the CONSTANT number to work out the tall target test
please My scope is in meter and clicks is mrad 0.1 cm Thank you my scope is 5/25/56 smith and bender

Sir, your scope is a Schmidt & Bender.

Translated to yards, each "click" of your scope will correct for .36" @ EXACTLY 100yds.

If you want to do a tall target test, use a contractors tape to measure EXACTLY 100yds from the center of your scope's housing.
Set a tall target up and mark a dot at the bottom.
Use a plumb line and mark a 2nd dot EXACTLY 36" above the first dot.

With the rifle leveled & secured firmly, put the xhair on the lower dot.
Dial 10.0mils UP on the scope's turret.
The xhair should now be centered over the 2nd dot, 36" above.

In closing:
0.1mil turret = .36" @ 100yds with each 'click'
_____________.72" @ 200yds
____________1.08" @ 300yds
etc...

1.0mil = 3.6" @ 100yds
_______7.2" @ 200yds
______10.8" @ 300yds
----------36" @ 1000yds

If you want to convert mils--->MOA, multiply mil correction by 3.438.

Once you get accustomed to the 1/10 based math using mils, you'll see how easy things become.
Don't keep trying to convert, just think in mils, and adjust in mils. Constantly reverting back to inches / MOA no longer applies, and only serves to confuse something that is quite simple...

Have fun learning, you've got a super optic to learn on! Odds are very good it will track true, but kudos to you for testing it, anway...