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View Full Version : So now they tell me.....



Pete K.
07-27-2010, 11:47 PM
When you finally have your adjustable scope set up just perfect and the POI is exactly where the POA is and you are extremely pleased with the setup you go and change the power setting. You were shooting SOooooo good at 100 yards on say 16X you just had to see what you could do on say 20X. You were able to sight on the last bullet hole on 16X and it would hit that same POA/POI!! Just terrific you think. Now you decide to set at 20X you see a bigger target where you can place the cross hair or 1/8" target dot anywhere you wish on the 2" bright red bull. You confidently hold on the center mass and gently squeeze one off and it barley touches the bottom 5 o'clock edge of the target. What the heck just happened??? You squeeze off four more rounds and see a nice group no where near the center of the bull where just minutes ago you owned the target.
So you read up on everything you can find and you learn that the POA changes with power setting adjustments. So does the POI as you just found out. Now you may be thinking that you really should trade in that adjustable power scope and buy a fixed quality scope in the 36X range for target shooting so it will not change POA/POI. Now you happen upon an article on the March scopes which in itself is difficult to find as they have only one distributor and very few articles. While reading about the very advanced and expensive March scopes you learn that they have overcome this problem with internal designs. If only you could come up with the $2400 or so for these terrific 10 X 50 X 60MM or so scopes you would have this problem licked as they say.
Ok, that isn't going to happen so what do we do instead? Do I set the scope to it';s maximum 20X, adjust the Parallax and clarity and just leave it where it is when satisfied or do I dare change the power setting and start all over again. What do hunters do when encountering game at different distances with adjustable power scopes???
I went from dead nuts on and seeing and hitting green 12 gage shot gun shell husks at 100 yards in seconds and white golf balls to hitting nothing much but dirt!! The two inch red targets are now off by around 1" low right and barely touching the outer edge.

Help please....

Pete K :o

Modified to add; Found this helpfull article but it still doesn't answer the problem of POA/POI shifting when the power setting is changed.

file:///C:/Documents%20and%20Settings/Pieter%20Klein/Desktop/Nikon/Parallax%20-%20And%20how%20scopes%20work.htm


I still need thoughts and help. PLZ.......

Matt Peetz
07-28-2010, 10:29 AM
If it is POI and POA is shifting while adjusting the power ring your scope is defective.
In all the scopes i have had i have not experienced this. Scopes ranging from nightforce to tasco varmints.

What scope do you have?

hotbrass
07-28-2010, 10:45 AM
I have read about it but I have not experienced this with any of my scopes. But I do buy good scopes to begin with. If it ever happened to me, I would send it back to the factory for repair.

Pete K.
07-28-2010, 12:39 PM
If it is POI and POA is shifting while adjusting the power ring your scope is defective.
In all the scopes i have had i have not experienced this. Scopes ranging from nightforce to tasco varmints.

What scope do you have?


Matt it is a Nikon Monarch UCC 6.5 X 20 X 44MM AO with fine cross hairs and 1/8" target dot. It has 1/8" clicks @ 100. It is sharp & clear and has been very carefully cared for. I use scope caps and a Scope Coat. It's never been dropped or banged. Friday I will got to the range at set the AO @ 50 with a white piece of paper then move out to 100, set the power at 20X and adjust for clarity. I will do a box test to check the movement adjustments etc. It may be that I had the AO out of adjustment so that what I thought I was aiming at was changing depending on my eye placement behind the scope. I'll have to check this out.

http://www.deon.co.jp/march/Benchrest_scope.html

Quote from this link;

"The EP Zoom Scope integrates a specially designed device with the March 50x52 BR Scope, eliminating the mechanically induced shift in POA during zooming which is inherent to all other zoom scope designs"


Pete K.

EFBell
07-28-2010, 01:52 PM
Now you see why Professor Hammer is so fond of fixed power scopes

21 Guns
07-31-2010, 03:49 AM
I'll bet money it's not the scope...

frank1947
08-03-2010, 12:58 PM
yes they will change poi go to nikon website they have a free ballistics software and you can pick a scope with maybe same power settings as yours and adjust the ranges and it will show you poi

http://www.nikonhunting.com/SpotOnRegistration/