I'm trying to sight in a rifle and ran out of adjustment when I got 4 inches below point of aim. I'm using low rings so if I used med or high rings would that help? I can't see how going higher with the optic would help but I'm probably confused. Any advice would be much appreciated.

What rings and bases? You could go to a 20MOA setup or I'd probably start by lapping the rings, centering the crosshairs in the scope and then resighting in.

Are the proper bases on the rifle in the right orientation?

If you can, try a different scope. If you have the same problem it's your mounts or rifle. Burris Signature rings have plastic inserts. The offset insert kit will allow you to correct for the problem.

I believe they are talley quick release rings with bases. The bases look like they are in the correct places. This is a pre 64 winchester model 70 action they are on. I bought the gun last week with the scope, rings and bases on it. Shot it yesterday and had this problem so I put a known good trijicon scope on it and this morning had the same issue.

Burris Signature rings with offset inserts should cure your problem.

Thanks guys

Won't cure the problem per se but may allow you to center the scope.

If that's right, figure out what the problem is and fix it. Shimming one way or another (that's what the Burris rings do) is a bubba fix IMHO. (But that's just me.)

So if I'm shimming or using the Burris rings the rear needs to go up some to raise the point of impact, is this correct?

Yes. In your mind see a line from the muzzle to where the bullet impacted. And see a line from the scope to where you aimed. Then see how the scope has to move so the aim point ends up at the point of impact.

good description right there...

You bore sighted first, right?

When I had this problem I determined which base I needed to shorten a tiny bit and then lapped the base against the receiver with sandpaper on it. It won't take much. Just go slow and keep checking.

Not exactly correct to shim the scope. Puts stress on the tube. Better to shim the bases as needed. Best of all is a tapered base.
Ring height means nothing and the lower to bore the better.

Furthermore, shimming the bases should only be done enough to bring the ring holes into alignment with each other. If you go farther than this in an attempt to Bubba up a canted base effect you're putting the scope in a bind.

Indeed. Check to see if the right bases are on it.

Some years ago I ordered a set of bases from Brownells which just didn't work. Compared them to the ones already on a similar rifle. Turned out to be a misprint in the catalog....

The Burris inserts are not the same as shims, because they do not stress the scope. The beauty of the Burris inserts is that they are curved, and pivot in their recesses, so stress on the scope tube is eliminated or at least reduced. Shimming places one ring out of parallel alignment with the other, so that the scope is contacted by one edge of the ring, which is a common source of ring marks.

Another way to deal with this situation is to build up one ring bottom with epoxy, so that there is full contact with the scope tube. I do it in a couple of steps, starting with a shim using a narrow strip of tape, then remove the tape strip and add a second coat of epoxy for full coverage. A bubba solution, but done carefully it works and is neat.

Paul

The Burris setup is pretty neat, might cost some, but you'll save your time.

You should make DANG sure you have the correct bases, but because this is a Model 70, it might be the way the receiver was put together way back when. But if it's in fact correct, then ---

I would get out the calculator, center the scope adjustments, fire a round, measure THAT below point of aim, divide distance of shot by distance between rings, and that will give you a good number of how much you have to shave, shim, or both.

Then, after you've put the bases back down, you will pretty much have to lap the daylights out of the rings to keep the scope happy.

Anybody know what number leupold std bases should be correct for a pre 64 model 70? I put some 50023 on and the rear base is about .0035" lower than the front if I put a strait edge a cross them. This is the problem but I need to figure out which ones are correct.

You could try swapping the rings around, that has worked hor me a time or two.

Leupold Mounts Selector

Squint!

When rings are on the base, tilting the base will not change a thing as far as scope stress. I have milled bases for long ranges but rings do not change at all. But put a shim in the ring and you can stress the scope. You change alignment from one ring to another. I do not trust the Burris system. Rings must be in line no matter. Now you might get it right but how do you measure? Roll the rear inserts to raise the back and where are the fronts? Best is the base movement. Shimming is always done under the base.

He said bases, as in plural for two piece. Shimming under one of those two pieces is definitely not the same thing as tilting a one piece base.

Try resetting your scope back to mechanical zero.This may get your adjustment back without having to change your mounts.Here are some videos on the subject.I ran into the same problem before too.I reset the scope back to zero and it gave the adjustment back.
https://www.youtube.com/watch?v=GZ-pF52t4TQ

Really?

Look today with long range rifles. The base will be milled for a 20 MOA change. ONLY the base. Thicker at the rear and never the rings. Now many rifles have different heights at the actions but they made bases to level the scope, never for extra long ranges. Yet you can shim the rear base to shoot far . Not as good as a one piece, One piece is still best. It keeps the scope in line with rings.
You want the scope to be near center with adjustments no matter. To be at extremes is bad on the scope. Also to go too far with elevation will effect windage too. Pads on a tube will move in and out.
A scope is easy to understand so don't bend the tube.

has worked for me several times

Signature rings work great. If there's any easy way to guarantee a mounting job free of stress on the scope tube, that is it. The offset inserts are really helpful when dealing with misaligned D&T on receivers. I use em on one or two rifles.

As I said, won't cure the problem but may allow you to center the scope.

Years ago, I got a Charles Daly 98 that had the rear scope base holes drilled off center. CD said they were within spec despite clearly not being centered and tilting to the right. A scope base would sit cockeyed. The shop that sold it actually felt bad for be and provided a set of Burris rings and inserts. Ultimately I redrilled (milled actually) the holes and re tapped for 8x40 screws. That fixed the problem, no band-aids.

Or, as I did as I don't have a machine shop and still building skills, modify the base. The first modified base was truly modified, into something other than a base.

My motto: Always work on the part cheapest to replace.

Sounds like they got the wrong bases on it. They probably put bases for a modern post 64 action on a pre 64. The rear bridge height on pre 64's is different than modern model 70's. Ran into this when putting modern bases on a pre-64. Some scopes may have enough vertical adjustment to compensate but the misalignment of the rings caused by the unequal base height stresses the scope tube and can bend it or leave nasty ring marks in your tube.

Yes, knives, even wunnderful wunnerful Winnies had manufacturing tolerances that stacked. Like all firearms, Winchesters were made by humans, not God.
Really.

Mechanically, it does not make sense. Only if the inserts can rotate sideways should it work so no matter how they are turned they will align with each other. To force one end over against a fixed other end is stress. I do not have any so I don't know. If they work like a round bushing in a race it is fine. A tilted base can be shimmed on one side to level but can be off center if the holes are off center. If the outsides of the inserts are rounded and fit a rounded ring cut so they can swing--good. If flat, NOT.
I need you to tell me how they are made.

That .0035" is enough of a difference to create your problem. Since you are using 2-pc bases you could likely shim the rear base .003-.004" and correct the problem. Alternatively you could use the Burris rings as suggested by others,

Of note, several years ago, about the time Winchester first introduced the Classic and brought back the CRF action, I purchased one brand spankin' new in 300Wby. Took it home, topped it with Leupold Std bases and rings and went out to shoot. Ran into the same issue that the OP has. Tried different bases, and base ring combos all to no avail. Took the gun back to where I purchased it, showed the gunsmith there the issue and he agreed that something wasn't right. The gun was returned to Winchester to have them look it over. About a month later I got a call to come in and pick my gun up. Turns out the gun I returned, DID have an issue with the bridge height, and Winchester replaced the rifle. Took my ring, bases and scope, mounted everything up, shot it and never had a problem.

Moral of the story is, the issue COULD be with the rifle itself.

You don't mention what kind of scope it is. I had the same issue with a zeiss conquest hd5 with target turrets. I did not realize but the zero stop was causing it. Zeiss sent me the instructions on how to change it and I fixed the issue.

Would be interesting to hear where limabean is at with this.

Thanks guys, I ended up shimming the rear base to get the rifle to shoot where it needed to. I still don't like this setup but it is working for now. I wish I could find some bases that would work without shims but no success yet.

Cool.

Shims are your friends, Lima. One thing you might want to try is getting some Loctite agent, it's not threadlocker but it's this creepy green stuff that acts like a bedding epoxy. 629 or something. But it will help give you full support of the rear base.

As for the shims themselves, once you've gotten everything down and done a neat job of it, with the rings lapped, you won't have a problem or even notice it is there. I have shims on lots of my toys, it's actually less aggravating than swapping stuff out or chasing parts.

Your bases are probably not in the proper orientation. I've never had to shim a pre 64 base.

Why not use the DD's?

Stick to golf.

I don't play golf and the bases that are on it now are leupold std bases but thanks for the suggestion.

Really like to see pictures of this setup

That's what I was thinking. I put a set of factory-recommended Leupold bases and rings on a standard pre-64 70 two weeks ago and had zero issues. That's with both the Weaver 3-9 Classic initially installed and then with the Leupold 3-9 that's on it now. No issues with bore sighting and final zero-ing with either scope. Both reticles were centered before installation and didn't require but a few clicks to get to final adjustment.

If there's one gun that had holes and dimensions worked out perfectly while in production, and one gun for which every scope mount maker in existence since the beginning of time has worked out the dimensions for its mounts, is the Model 70. If someone is having troubles of this nature I daresay there's a gremlin in the wood pile not caused by the gun or the mounts (if the correctly matched ones were used).

The shim guide says .001" at 100 is 1", .002" is 2", .003" is 3 ", etc.

What ring spacing is assumed here?