Why does my zero keep wandering?
#1
Thread Starter
Fork Horn
Joined: Feb 2003
Posts: 494
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From: Altadena CA
Every time I go shooting my zero has wandered a few inches at 200 yards. The groups are always great (often 2" @ 200 yds, which is good for my bad eyes), but they keep wandering. I' ll re-adjust it a few clicks to dead on, but the next visit the group has moved.
This also happens on the same day when I readjust for 600 or 1,000 yards, then move the scope back to 200 yds afterwards. Temperature doesn' t seem to be a factor, so I' m wondering what' s causing this.
Here' s the set-up: Model 70 Classic Stainless in .300 Win Mag with BOSS at the factory setting. 2.5-8 Vari-X III. 180 gr Sierra ProHunters ahead of 75 gr of RL22 (2950-3000 fps). (The problem also occured when I was shooting 2850 fps with 70 gr of IMR 4831.)
I sent the scope back to Leupold, who found defective internals, which they said they replaced. The problem continued. I also switched out the factory plastic stock with a glass bedded HS Precision stock, but the problem remains.
Any suggestions where to go next? Sure would appreciate your input. (I still suspect the scope, but I' m not an expert at this stuff.) I' m spending a lot on bullets and powder!
This also happens on the same day when I readjust for 600 or 1,000 yards, then move the scope back to 200 yds afterwards. Temperature doesn' t seem to be a factor, so I' m wondering what' s causing this.
Here' s the set-up: Model 70 Classic Stainless in .300 Win Mag with BOSS at the factory setting. 2.5-8 Vari-X III. 180 gr Sierra ProHunters ahead of 75 gr of RL22 (2950-3000 fps). (The problem also occured when I was shooting 2850 fps with 70 gr of IMR 4831.)
I sent the scope back to Leupold, who found defective internals, which they said they replaced. The problem continued. I also switched out the factory plastic stock with a glass bedded HS Precision stock, but the problem remains.
Any suggestions where to go next? Sure would appreciate your input. (I still suspect the scope, but I' m not an expert at this stuff.) I' m spending a lot on bullets and powder!
#2
Fork Horn
Joined: Feb 2003
Posts: 459
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From: Lexington NC USA
Years ago I had a Remington semi-auto .22 that would do the same thing. You could zero the iron sights dead on at 50 yards, get it out the next day and and it would shoot the same 1.5" group 6 inches in another direction. One day it would go right, the next it might go left, up, or down. Put a scope on it and did the same thing. Mine didn' t have anything to do with weather either. I finally sold it for $50 at a gun show. My dad had the exact same rifle, only 10 years older. His will hit dead on the bullseye everytime. Go figure.
#3
Joined: Feb 2003
Posts: 262
Likes: 0
From: Nowhere
Since its only a couple of inches at 200 yds, I would say you are probably dealing with paralax. If you have a scope with adjustable objective, put it on and see what happens. Or just try shooting the 2.5x8 at the yardage its set to be paralax free at, which I think will be 150 yds. My first guess.
#4
Nontypical Buck
Joined: Feb 2003
Posts: 3,393
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From: Western Nebraska
The problem you described seems very minor to me.......it' s a couple inches at 200 yards?.....and the groups are still good but off center?......this seems like simply relieving of stress in the barreled action to me.....it' s a normal and natural thing that goes on for up to five years.....it doesn' t happen over night.....it' s a change that happens over several months.....relax.....it' ll be ok!!
Damn few riflemen can detect that stress relieving.....congrats.....you' re one in a thousand.
Damn few riflemen can detect that stress relieving.....congrats.....you' re one in a thousand.
#5
Joined: Feb 2003
Posts: 389
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From: Newport Maine USA
Stress Relieving?takes a couple years to stop? A natural thing?Wow my guns have shot well from the start or I found out why and fixed them,maybe Savages don' t need to stress relieve themselves(pillar bedding and floating barrels).I would suspect the scope since they found problems and changed some internals already.Parallax,unless you hold your eye in exactly the same position each time won' t result in tight groups slightly off center,but will tend to scatter your shots slightly.If possible try another scope of some kind so you can eliminate the scope as a possibility.At the same time if you use the same mounts it can eliminate them also.Synthetic or wood stock?
woods
woods
#6
Guest
Posts: n/a
Well, think there has been one thing that you said was found defective. I would try a friends scope that is tried and trusted. Also, maybe the way the scope is mounted. If your using dovetails for the front on a two peice base, and adjusted the windage screws in the back alot, this puts alot of stress on the scope while it is tightened down in the front.
I really don' t see zero being off from the gun or barrel stress' s unless your taking the action out of the stock every time. That might do it.
I really don' t see zero being off from the gun or barrel stress' s unless your taking the action out of the stock every time. That might do it.
#7
Typical Buck
Joined: Feb 2003
Posts: 563
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From: Greensboro NC USA
BTM,
I am assuming that your H-S stock is free floated, so I would eliminate that. If it is not free floated, get it free floated. It could be the factory barrel does indeed have stress in it, due to not being properly stess releived from the factory. It could also be due to parallex, but with a 2.5-8x scope, you can' t do much about it.
There again, it very well may be changes in the weather conditions. Changes in air temps, barometric pressures, humidity, winds, etc., always have some kind of effect on a bullet' s trajectory and flight, some times minor, some times major effects. As the ranges increase so do the amount of the effect of the atmospheric conditions.
I am assuming that your H-S stock is free floated, so I would eliminate that. If it is not free floated, get it free floated. It could be the factory barrel does indeed have stress in it, due to not being properly stess releived from the factory. It could also be due to parallex, but with a 2.5-8x scope, you can' t do much about it.
There again, it very well may be changes in the weather conditions. Changes in air temps, barometric pressures, humidity, winds, etc., always have some kind of effect on a bullet' s trajectory and flight, some times minor, some times major effects. As the ranges increase so do the amount of the effect of the atmospheric conditions.
#8
Thread Starter
Fork Horn
Joined: Feb 2003
Posts: 494
Likes: 0
From: Altadena CA
Thanks for your input, gents!
Scope is focused for 150, and I don' t see how paralax could be the cause of such radical shifts in POI. Rifle is 5 years old and has had 1500-2000 rounds through it, so it' s probably stressed relieved and then some. Barrel is free floated. I' ve done enough shooting in enough different conditions to have ruled out atmospheric conditions.
I think it' s time to send the scope back to Leupold.
Scope is focused for 150, and I don' t see how paralax could be the cause of such radical shifts in POI. Rifle is 5 years old and has had 1500-2000 rounds through it, so it' s probably stressed relieved and then some. Barrel is free floated. I' ve done enough shooting in enough different conditions to have ruled out atmospheric conditions.
I think it' s time to send the scope back to Leupold.
#9
Joined: Feb 2003
Posts: 352
Likes: 0
From: Raleigh NC USA
Hey BTM, considering the wide geography of people on these forums we' re practically neighbors. I' m curious what type of hunting you do, and what general area you go to. A friend and I have recently purchased rifles and just joining the sport. Have to submit our info and try to get a deer tag soon. We' re also kicking around the idea of imposing on my relatives back east, hunting in Pennsylvania, Kentucky, or Georgia.
#10
Thread Starter
Fork Horn
Joined: Feb 2003
Posts: 494
Likes: 0
From: Altadena CA
Calnewbie: I' m primarily a bowhunter, but a few hogs and deer have fallen to my firearms. If you want to get started locally, there are plenty of places to hunt hogs in Central CA for not too much money, plus the eatin' is great! Wish I had someone back east who' d let me hunt on their land.
If you want more info re. hogs, give me a buzz: [email protected]
If you want more info re. hogs, give me a buzz: [email protected]


