Pre-64 M70 Scope Mounting Oddity

[Bigslug]

My pop and I have a pair of pre-64 .30-06 standard weight rifles - one Super Grade from 1947 and one Standard from about 1952.

Both rifles exhibit the same strange behavior.

We initially tried to set them up with Leupold QRW Weaver/Picatinny bases so we could QD to the iron sights if desired, but we ended up having to max out the windage on the scopes to one extreme to get them zeroed. We switched to Leupold STD dovetail front/windage rear bases to deal with that.

I switched out the scope on the Standard Grade to a low magnification 1.5-5 a couple days ago. Have not shot it in that configuration yet, but at 1.5x, you can see the front sight in the scope. Aligning the vertical crosshair with the front sight took all the "left" windage the base had to offer (right side screw all the way in / left side all the way out), plus a fair bit of what the scope had as well (glad that it has 125 MOA to work with).

I would be willing to chalk ONE of these guns up to someone at the factory having a bad day at the mill, but TWO of Winchester's flagship models, made five years apart, filtering down through the years to end up in the same place, exhibiting the same problem strains my credulity a bit.

FWIW, the forend stud screw under the rear sight is missing from my Standard Grade. Replacement has been ordered and we'll see if that changes anything. Not immediately sure about the state of my Dad's.

I'm wondering if this is a "known thing" with Model 70's that just isn't known to me yet.

What say the Hive Mind?

[Texas by God]

I'm not much help here, but every low powered scope that I could see the front sight in- when sighted in- did not line up vertical hair to sight.
I think that I would center the adjustments on the scope, center windage on the rings, then bore sight it to see what's up. I agree; two mis- milled actions years apart would be way strange!

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[Mk42gunner]

Not sure about the Model 70's, but I have had a few of the smaller Leupold variables 1-4X and 1.5-5X on several different rifles. They have such a wide field of view on the lowest setting it is common to see the front of the barrel in the scope. Not always centered when finally sighted in either.

My advice is to shoot the rifle on paper to get a good zero, then just ignore the barrel in the field of view.

Robert

[Bigslug]

Not sure about the Model 70's, but I have had a few of the smaller Leupold variables 1-4X and 1.5-5X on several different rifles. They have such a wide field of view on the lowest setting it is common to see the front of the barrel in the scope. Not always centered when finally sighted in either.

My advice is to shoot the rifle on paper to get a good zero, then just ignore the barrel in the field of view.

Robert

Well, yes, that was done with the 4.5-14 (30mm) and 3.5-10 (1") through which the sight could not be seen. Been a few years, but as I recall on the QRW rings, so much windage needed to be sucked out of one of the scope's adjustment that the amount of available elevation was severely reduced. In the case of the 1.5-5, the misalignment was plainly visible as a clue. Gonna shoot it this week to confirm, but it's plain from all of the above experiences that something's rotten in Denmark.

[tazman]

I had a friend that bought a Winchester model 70 many years ago. It had the mounting hole misaligned so badly you could see it just by looking.
He had a gunsmith remove some metal from the side of one of the bases. This brought it right in so he could properly adjust the scope.

[eastbank]

i have had several rifles with factory scope base screw holes out of alienment, not limited to cheap rifles either.

[243winxb]

Shims & base mounts with windage screws , would seem to be needed. Plus a good gunsmith.

[M-Tecs]

You just got "lucky".

I have built a couple of dozen NRA Match Rifles for friends and local competitors on pre-64 action plus owning 9 of the same in hunting rifles or match rifles. I have not had any windage issues with them.

If you want them repaired I would recommend Chad Dixon of https://www.longriflesinc.com/collec...winchester-m70

He thread mills the 6-48 mount holes to 8-40 on CNC equipment. That is by far the best method to repair misalignment of mounts holes. Next is using a boring bar or custom sized endmill. Drill bits tend to follow the existing holes.

[Bigslug]

My rifle builder buddy says it is a known thing. I've got it zeroed at 25Y in prep for Friday, so I'm functional, but I'm still a bit vexed.

I pulled the scope off in the midst of all this and broke out the straightedge of a four-foot drywall square. That line runs straight through the tops all four screw heads directly to the front sight blade. . .yet aligning the scope with that front sight blade requires the aforementioned removal of nearly all windage from the rear base.

[sigep1764]

Swap the bases. See if the problem is the exact opposite. If the brand and model of rings is the same for each rifle, I imagine it is the rings.