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Scope base not aligned with barrel?

upacreek

Well-Known Member
Joined
Dec 6, 2012
Messages
271
Location
Caldwell, ID
I personally own a Winchester M70SA in 7WSM that if you center the windage adjustment and use leupold windage bases the windage adjustment is around 1/8" off center. I have a good friend who just bought a brand new M70LA in 264WM. His one piece base and wings would not allow the rifle tozero windage on initial sight in. The windage adjustment bottomed out. After a few scopes and a couple one piece bases he opted for the leupold windage bases and found the same thing my rifle has.
Does anyone have experience with this? My buddies scope is a brand new huskemaw and mine is a vortex. Is this a barrel alignment problem? To look at the action it would be obvious if the scope mount was off center that far and my naked eye cannot see any discrepancies. What should we look at? Once set up they act like a normal rifle, nothing weird about how they shoot.
 
I personally own a Winchester M70SA in 7WSM that if you center the windage adjustment and use leupold windage bases the windage adjustment is around 1/8" off center.

Is that 1/8 inch off center on target or 1/8 inch off center from the center bore of the rifle?

I have a good friend who just bought a brand new M70LA in 264WM. His one piece base and wings would not allow the rifle tozero windage on initial sight in. The windage adjustment bottomed out.
Did he bed the one piece scope base? Has he tried Burris Signature rings with inserts?

Did you do it like this:

 
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Both guns ends up with leupold windage adjustable bases. At the rear adjustable base the ring is off center to the base by 1/8". Very noticeable. Can't remember which bases my friend used, but they were reputable for sure.
No I am not familiar with 'bedding' a scope. Honing the rings is not the issue. It's way more significant than that.
 
Had the same issue with a Remington 700 and took it to a gunsmith. Like the OP, I had used Leupold windage adjustable mounts as a Band-Aid fix, but wanted to mount my scope with a Picatinny rail.

I was wondering if the receiver was mis-drilled or if the barrel was that out of square with the receiver. The problem turned out to be much more simple than that.

The smith said the mounts were "off" and needed to be machined for proper fit to my receiver. It was an easy and inexpensive fix. My scope is now mounted squarely and securely.

I had the same problem with both Remington 700's that I have owned. Never had that problem with any of my other rifles. I guess the OP's issue goes to show that it can happen with any make of rifle.
 
If you find it is a defect from the factory, definitely contact Winchester before you have it corrected....any work you have done outside their authorization may void your warranty.
 
I'm fighting this problem at the moment.

I switched from the rear mount windage mounts as heavy recoil in shorter time than one would think the ring base gives out at the little wedgie thing that seats into the screw.

In my braked 338 Rum it simply sheared off. On my 270 AM It wore so that the screw came up against the base allowing the ring to kind of float. Groups went to hell in a hand basket all at once with both rifles.

Switch to double dovetail Burris Zee rings with the 10 MOA inserts on both rifles. The Rum zeroed fine.

The AM built on a old Rem 721 lacked about 4" windage @ 100 to zero. I simply rotated the rear inserts 90 degrees in the proper direction after a couple of brain-farts, and she works just fine.

However a full 8th of an inch is a considerable amount. May be a big problem....
 
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