Tricky Optics question??? HELP

T.Zimm · #1 03-25-2007, 03:17 PM

Good morning! Friday I did some longer range testing on my new .204 Ruger. My friend has a small steel flag at 253 yards. I have a 4-12 AO Nikon Monarch scope on my rifle. I started by zeroing one inch high at 100 yards. Then sighted on the flag and smacked it twice. I then noticed that the image was a bit fuzzy so I adjusted the objective to 250 on the dial. I then promptly missed the flag twice. So I moved it back to the 100yd. setting and HIT it twice more. Now I am not an OPTICS guy, but I didnt think that by changing the objective focus you would change your poi. Anyone know what could be going on here? Thanks Tyler.

sicero · #2 03-25-2007, 03:54 PM

I am guessing there are several possible answers. You didn't say how big the flag is. Maybe the 250yd setting is correct and the distortion from the 100yd setting is getting you hits when in reality it should be missing. The first thing I would try is shoot the 100yd target on the 250 setting. If you are 1" high at 100 it would drop to maybe 1.5" below at 250. Just a thought. Kenny

T.Zimm · #3 03-25-2007, 04:34 PM

I have not tried that yet, and that was my next thought. The steel flag is 3"X5". Thanks for the thoughts.

Daryl · #4 03-25-2007, 04:41 PM

I've never tried using a steel wind flag. That must be a prairie requirement.

: A non-perfectly ground lense will change point of impact if it is rotated. his is, I assume, why some scopes change point of impact when power rings are changed. It's a good test for optics. I think Kenny's probably spot-on with his guess.

muzr257 · #5 03-25-2007, 07:28 PM

You will find that when using a collimator, POI can change with both power change AND paralax adjustment - i mounted a Nightforce the other day that had no power shift poi but did have a small vertical poi with the paralax, so it happens even in the very best scopes. Normally it only happens either at a very close range ie 10-25yards, or sometimes infinity.

Murray

BJS17 · #6 03-25-2007, 08:25 PM

Maybe it was purely coincidental and you just happened to have missed on those two shots ?? I'd shoot on paper to see what is really happening.

T.Zimm · #7 03-26-2007, 12:40 AM

Quote:

Originally Posted by BJS17

Maybe it was purely coincidental and you just happened to have missed on those two shots ?? I'd shoot on paper to see what is really happening.

I am going to put it on a target at 200 yards and see what is going on. I will re-post with the results.