Parallax....define it for me again.....

[cloverleaf]

OK, so 60 hours a week for the last 3 weeks with no OT pay earns me a little range time......
So I am sitting behind my "beloved aggravation" my 250 Savage at 87 yards cause the 100 yard range is full... :roll: and I touch off a few. Slow and easy, consistoient position in the rest, fundementals, breathing, stock pressure even, consistient sight picture.... in short I am this far away from my favorite "zen" state. First shot, at about 4:00 in a one inch dot.... We are happy.... (Rare for me). the following 3, about 1/2 an inch, to an inch, to the left right. Now I am having a good day. I have been calling shots with my 22 at the same range with a partner spotting for an hour prior to this.
I snuggle up behind "beloved aggie" again, and as I do I notice the vertical wire move across the dot on the target- and I havent touched the rifle. I bob back and forth a little bit and sure enough the vertical wire moves from one side of the dot to the other depending on where my head is. Parallax right? Could this be, because I am not at a full 100 yards? IF I call Luey in the a.m. (its a VX-II) they are gonna say, "yea right, send it in we'll take a look" but some how I dont think they are gonna find any thing. Is my diagnosis off? Could the scope be mounted not parralel with the boere and cause this? I hate to take the thing off the rifle for nothing. Its been back before cause I dropped the rifle and the power change ring didnt "feel right" but Leupold gave it a clean bill of health. Thanks for the thoughts. CL

 

[Guest]

CL, you may be seeing parallax issues. Your scope is very likely set to be parallax free at 150yds. Cutting that distance roughly in half would introduce some parallax between the target distance and the reticle's "focal plane distance" (or parallax setting). How much is the reticle moving in relation to the target? Sounds like about 1" or so. That seems a bit excessive, but maybe I'm misjudging what you'd see. If you can set up at 150yds on the same style of target dot (even if you just do it in a pasture with the bolt out of the gun) you can check it. I suspect, ultiimately, that's what you're seeing, though I'm curious as to the power setting on your scope when you noticed this. At lower powers, say with the scope set somewhere between 2 and 8 or 9, parallax should not be as noticeable. I find it more noticeable at 10x and up. That's why I don't own any scopes stronger than 3-9x without a parallax adjustment. And, everyone's eyes are different, so it might be more or less noticeable to different shooters.

The good news is, you can solve this one. Just get very consistent with your head position and cheek weld. Define a few key anchor points, like where the stock hits your cheek, and where your hands are in relation to your face, and exactly where in your shoulder the butt of the gun should sit. Get very familiar with what it feels like to be in perfect position. (It sounds like you were in perfect position for that first group...just duplicate what that feels like) and practice it regularly, including some dry firing to determine where your crosshairs are going when you break the sear and the pin drops. It's kind of like bowhunting (don't know if you've ever shot a bow or not) in that you have to anchor the same each time in order to get the same shots and the same point of impact. All non-adjustable scopes do this, unfortunately. And the cure isn't to add some whizbang adjustable scope to your 250. That just introduces a moveable parallax and means you have to make one more adjustment prior to every shot.

 

[cloverleaf]

Dub,
Thnaks for the thoughts. Scope was set on 9X and I could visually see 1/2 inch of movement to either side of a 1 inch dot. thought that was abit much. Yes I have shot the bow a little, recurve mostly. Understand exactly what you are saying. I tried to really pay attention to what "centered" looked and felt like once I noticed the problem yesterday. I am probably not good enough or practiced enough to hold that consistiently yet. There are some muscle control factors involved here too. Maintaining a consistient sight picture is important and tricky- as you know. Even with a one inch bull. Do you hold on top of the dot? to a side edge? What will give me the most repeatable sight picture....? Hence the fine cross hairs in a target scope. At 9X the standard Luey cross hairs cover at least a 1/4 of an inch..... (its part of why I enjoy the challenge) Us "rifle looney's" need some serious help dont we...? When not shooting "Aggie" I spent the remainder of my time shooting the .22 at the same distance trying to cut the stem of varios milkweeds growing on the backstop. with a 4 bushnell I was successful on the third shot. (I am so easily entertained.... )

I spoke with Leupold customer service today and the initial suggestion was " try it at 100 or better and see how it goes" and then he says. "Ive got one laying here on the desk thats in for a colmination check and that one dosent show as much movement as you are getting.....maybe you better send it in." :roll: Really dont want to do that, but in the end I probably will.

Thanks for the reply- CL

 

[cloverleaf]

Well, I pulled the scope and sent it in back. It arrived May 23rd. Called and checked on it today. "yes....it has arrived, we have it here.....it should be about three weeks to get through assessment and repair....then another week to get it back to you" :shock: Apparently everyone wants a CDS reticle converson. Two weeks my Arkansas Mule....

 

[SJB358]

Hope it is good to go when you get it back CL.

 

[Ridge_Runner]

parralax in a scope makes the target and reticle appear to be on different focal planes, if you leave your head in the same place and just move your eye to look through a differnt place in the lense the crosshair will appear to move on the target, however at 87 yards you should not have a shift of impact of an inch just from parrelax.
RR

 

[cloverleaf]

parralax in a scope makes the target and reticle appear to be on different focal planes, if you leave your head in the same place and just move your eye to look through a differnt place in the lense the crosshair will appear to move on the target, however at 87 yards you should not have a shift of impact of an inch just from parrelax.
RR

So Ridge- Im a little dense and not quite following you. You are saying that the movement of that vertical crosswire from left tor right would be normal and expected? If so then my 2inch group is operator error. Maybe I gotta find a different hobby..... :? CL

 

[Oldtrader3]

I would be willing to bet that the parallax issue that you have been having is resolved when you get the scope back from Leupold. They usually do a pretty good job of setting the two crosshair lenses to appear to be on the same focal plane. We can talk again and in greater detail when you get the scope back and see how it compare before and after Leupold repair when compared at 100 yards.

 

[Ridge_Runner]

parralax in a scope makes the target and reticle appear to be on different focal planes, if you leave your head in the same place and just move your eye to look through a differnt place in the lense the crosshair will appear to move on the target, however at 87 yards you should not have a shift of impact of an inch just from parrelax.
RR

So Ridge- Im a little dense and not quite following you. You are saying that the movement of that vertical crosswire from left tor right would be normal and expected? If so then my 2inch group is operator error. Maybe I gotta find a different hobby..... :? CL

what I'm saying is IME parralax was never much of an issue with a 9 power scope if it is set correctly at 100 yards, then 13 yards difference isn't gonna make a bughole a 2" group. I never bother with setting it unless I'm shooting beyond 200 yards and on 12X or greater.
RR

 

[cloverleaf]

Well, I guess I will eat a little crow.... scope sent in on the 19th May, back June 11th. On the other hand, the paprwork says: Paralax adjusted, Focus adjusted, Erector system replaced, full disassembly, inspection and reassembly. So I wasnt all wrong :shock: and my neurotic tendencies paid off. I may not be able to shoot it any better but...at 3x I can read the "fathers day" fine print on the calender across the living room, great eye relief and full field of view holding it buy hand. So far so good.
Thought about trying to mount it up tonight but decided I was too tired tonight. Will get some time off in the next week or two and get her set back up.
Somebody with more knowledge than me explain exactly what the erector system is.....? In laymans terms I assume its the "tube inside the tube" that holds the crosshairs....CL

 

[Oldtrader3]

That is the "erector system", the tube inside the tube, with those lenses involved in the barrel cam action movement for smooth power (magnification) ring control adjustment and for setting the windage and elevation adjustments by moving the erector tube on their two axes with the turret knobs.

 

[cloverleaf]

Spent the evening getting her mounted up again. Everything looks SO much better at this point. I even took some time off on Mondy with the intent of sighting her in. Here's hoping that all goes well. CL

 

[Oldtrader3]

I had a similar issue with my 2002 Leupold VXII 3-9x40 scope about a year ago. I sent it back to Leupold and they did the same things that they did to your scope. Mine was gone 2 weeks and works great now. It is also much clearer and brighter than before they fixed it.